Conservation of Marine Birds of Northern North America : Papers

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CONSERVATION OF MARINE BIRDS OF NORTHERN NORTH AMERICA

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UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE Wildlife Research Report 11 WILDLIFE RESEARCH REPORTS

This series comprises reports of research relating to birds, mammals, and other wildlife and their ecology, and specialized bibliographies on these, issued for wildlife research and management specialists. The Service distributes these reports to official agencies, to libraries, and to researchers in fields related to the Service's work.

Library of Congress Cataloging in Publication Data

Conservation of marine birds of northern North America.

(Wildlife research report; 11) Supt. of Docs, no.: I 49.47/4:11 1. Sea birds— North America— Congresses. 2. Sea birds— Northwest, Pacific—Congresses. 3. Birds, Protection of— North America—Congresses. 4. Birds, Protection of— Northwest, Pacific—Congresses. 5. Birds—North America—Congresses. 6. Birds—Northwest, Pacific—Congresses. I. Bartonek, James C. II. Natural Resources Council of America. III. United States. Fish and WildUfe Service. IV. Series. QL681.C59 333.9'5 79-607005

Use of trade names does not imply U.S. Government endorsement of commercial products. CONSERVATION OF MARINE BIRDS OF NORTHERN NORTH AMERICA

From the collection of

International Bird Rescue Research Center

Cordelia, California

in association with

n m Prelinger V Jjibrary

h P I:

San Francisco, California 2006

CONSERVATION OF MARINE BIRDS OF NORTHERN NORTH AMERICA

Papers from the International Symposium held at the Seattle Hyatt House, Seattle, Washington, 13-15 May 1975

Edited by James C. Bartonek and David N. Nettleship

Sponsored by Natural Resources Council of America National Audubon Society National Wildlife Federation U. S. Department of the Interior, Fish and Wildlife Service

UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WILDLIFE SERVICE

Wildlife Research Report 11

Washington, D.C. • 1979 Dedicated to the Memory of Robert D. Bergman, Leonard A. Boughton, and J. Larry Haddock, Wildlife Biologists of the Fish and Wildlife Service, and Robert Johnson, Pilot of the Office of Aircraft Services, all of the U.S. Depart- ment of the Interior, who perished in the Gulf of Alaska on 30 September 1974 while conducting aerial surveys of marine birds, and to Einar Brun, Professor of Zoology in Troms6 University and a con- tributor to these proceedings, who perished in the Vega Sea on 13 July 1976 when returning from making aerial surveys of marine birds.

IV Contents

Page Foreword, by Harvey K. Nelson vii Introduction, by Lynn A. Greenwalt ix

Marine Environment of Birds 1 Long-term Climatic and Oceanographic Cycles Regulating Seabird Distributions and Numbers, by M. T. Myres 3 Sea Ice as a Factor in Seabird Distribution and Ecology in the Beaufort, Chukchi, and Bering Seas, by George J. Divoky 9

Status of Marine Bird Populations 19 Distribution and Status of Marine Birds Breeding Along the Coasts of the Chukchi and Bering Seas, by James C. Bartonek and Spencer G. Sealy 21 Breeding Distribution and Status of Marine Birds in the Aleutian Islands, Alaska, by Palmer C. Sekora, G. Vernon Byrd, and Daniel D. Gibson 33 The Historical Status of Nesting Seabirds of the Northern and Western Gulf of Alaska, by LeRoyW. Sowl 47 Status and Distribution of Breeding Seabirds of Southeastern Alaska, British Columbia, and Washington, by David A. Manuwal and R. Wayne Campbell 73

The Biology and Ecology of Marine Birds in the North 93 Trophic Relations of Seabirds in the Northeastern Pacific Ocean and Bering Sea, by David G. Ainley and Gerald A. Sanger 95 Population Dynamics in Northern Marine Birds, by William H. Drury 123 Time-energy Use and Life History Strategies of Northern Seabirds, by Erica H. Dunn 141 Zoogeography and Taxonomic Relationships of Seabirds in Northern North America, by M. D. F. Udvardy 167 Conflicts Between the Conservation of Marine Birds and Uses of Other Resources 171 Social and Economic Values of Marine Birds, by David R. CUne, Cynthia Wentworth, and Thomas W. Barry 173 Resource Development Along Coasts and on the Ocean Floor: Potential Conflicts with Marine Bird Conservation, by Donald E. McKnight and C. Eugene Knoder 183 Mortality to Marine Birds Through Commercial Fishing, by Warren B. King, R. G. B. Brown, and Gerald A. Sanger 195 Interactions Among Marine Birds and Commercial Fish in the Eastern Bering Sea, by Richard R. Straty and Richard E. Haight 201 Interrelations Between Seabirds and Introduced Animals, by Robert D. Jones, Jr., and G. Vernon Byrd 221 Oil Vulnerability Index for Marine Oriented Birds, by James G. King and Gerald A. Sanger 227

Programs and Authorities Related to Marine Bird Conservation 241 Programs and Authorities Related to Marine Bird Conservation in Washington State, by Ralph W. Larson 243 Programs and Authorities of the Province of British Columbia Related to Marine Bird Conservation, by W. T. Munro and R. Wayne Campbell 247 Petroleum Industry's Role in Marine Bird Conservation, by Keith G. Hay 251

V Conservation of Marine Birds in Other Lands 259 Conservation of Marine Birds in New Zealand, by Gordon R. Williams 261 Marine Birds in the Danish Monarchy and Their Conservation, by Finn Salomonsen 267 Present Status and Trends in Population of Seabirds in Norway, by Einar Brun 289 Symposium Summary 303 Conservation of Marine Birds of Northern North America—a Summary, by Ian C. T. Nisbet 305

Appendix. Papers and oral summaries presented at the symposium but which do not appear in this publication 319 Foreword

The international symposium "Conservation of Marine Birds of Northern North America" was convened because of a growing awareness that not all was well with our marine birds. The symposium provided a forum for scientists, governmental administrators, conservationists, and laypeople to discuss the diverse topics and issues that we must all understand if we are to act both responsively and responsibly to assure that marine birds will not be lost through our neglect. The symposium was cosponsored by the Natural Resources Council of America, National Audubon Society, National Wildlife Federation, and the U.S. Department of the Interior, Fish and WildHfe Service; additional support was provided by the Canadian Wildlife Service, the International Association of Game, Fish, and Conservation Commissioners, the Pacific Seabird Group, the Sierra Club, the Smithsonian Institution, the Wildlife Management Institute, and the Wildlife Society. Persons interested and knowledgeable in the many and varied aspects of marine bird conservation were invited to participate in this symposium. There were 139 registered and several

score of unregistered participants in attendance. Major topics treated were: (1) socioeconomic

considerations and conservation of marine birds; (2) the marine environment of birds; (3) status of marine bird populations on land and sea; (4) the biology and ecology of marine birds in the North; (5) conflicts between the conservation of marine birds and uses of other resources;

(6) programs and authorities related to the conservation of marine birds; and (7) conservation of marine birds in other lands. The objective of the symposium was to identify problems and the needed information and programs necessary for the conservation of marine birds of northern North America. For the purpose of this symposium the term "northern North America" referred to the coasts of Wash- ington, British Columbia, Alaska, Yukon Territory, and Northwest Territories and the adjacent North Pacific and Arctic Oceans. "Marine bird" was defined as being any bird using marine or estuarine waters. Speakers were asked to describe the status of information or the state of the art as it pertained to their topic within the limitations set by the objective of the symposium. Examples from other regions and of bird species not found in the regions of concern were to be used for comparative purposes when little pertinent information was known for regions or species of concern. Speakers were asked to identify the gaps in the knowledge and methodology that are most critical to their topic.

I believe that this symposium was particularly successful in that it provided a timely forum for many scientists who were about to embark on studies of marine birds in those areas of Alaska and California being considered for outer continental shelf oil and gas exploration and development. These pubUshed proceedings may be of lesser importance from that standpoint because some data, particularly those on populations, are out of date. However, I believe that the proceedings will long be of importance to biologists and administrators alike in charting their respective courses to ultimately assure conservation of this valuable avian resource. Many people from many organizations and agencies worked hard to put together the symposium in the relatively short time of about 8 months. Nathaniel P. Reed was the person primarily responsible for bringing this symposium to fruition. The Steering Committee was composed of Daniel A. Poole, John S. Gottschalk, David N. Nettleship, Amos S. Eno, C. Eugene Knoder, Warren G. King, Louis Clapper, Robert Hughes, Fred G. Evenden, James C. Bar- tonek, and me. James C. Bartonek, Warren G. King, David N. Nettleship (Cochairmen), C. Eugene Knoder, David A. Manuwal, William H. Drury, and Spencer G. Sealy served on the Program Committee. David A. Manuwal and Terence R. Wahl arranged trips for persons to observe pelagic birds off the Washington coast and other birds on Skagit Flats. C. Eugene Knoder handled financial matters. John A. Sayre and Richard Bauer made arrangements for facihties and entertainment. Elaine Rhode prepared the program and abstracts for printing. John Pitcher kindly contributed the artwork used in this publication as well as that used in the program and abstracts. George Reiger made general introductions to the symposium; Spencer G. Sealy, Daniel W.

Anderson, and I served as Session Chairmen; and James C. Bartonek served as General Chair- man. Elvis J. Stahr was guest speaker at the symposium banquet. Most credit for the success of this symposium goes to the 52 persons who as authors, coauthors, or summarizers of sessions presented much meaningful information in their presentations, during recorded discussions, and during many informal occasions. I wish to make special recognition of Ian C. T. Nisbet for his skillful summary of the symposium. Editorial assistance in preparing the proceedings was provided by Judith Brogan.

Harvey K. Nelson

Chairman of Symposium and Director of Wildlife Resources

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Introduction

Migratory birds make up a resource that is shared by many people of many nations. Public awareness of marine birds— their manifold values, ecological requirements, and problems—is prerequisite to their protection. I am proud that the Fish and Wildlife Service can further this needed awareness by publishing these proceedings of the international symposium "Conservation of Marine Birds of Northern North America. Lynn A. Greenwalt, Director Fish and Wildlife Service

MARINE ENVIRONMENT OF BIRDS

Long-term Climatic and Oceanographic Cycles Regulating Seabird Distributions and Numbers

M. T. Myres

Department of Biology, University of Calgary Calgary, Alberta, Canada T2N 1N4

Abstract

Seabird ornithologists have generally paid little attention to the possible roles played by long-term climatic cycles or air-ocean interactions on population changes at established colonies or on the processes of colony establishment or extinction. Yet, a rapidly expanding literature in the physical sciences suggests that seabird numbers are not naturally stable at particular colonies for any great length of time. It is suggested that the establishment of new colonies at one end of the range may counter the decline of colonies at the other end. Perhaps these changes in small marginal colonies are important, and they may be more indicative and significant (when detected and explained) than are much larger changes in numbers in bigger reproductive units in the center of a species' range. Fluctua- tions in seabird numbers must in future be first considered as possible responses either to short-term, or turnarounds in longer term, natural climatic or oceanographic cycles, or to trends ranging in length from a few years to at least several decades.

During the last 30 years extensive litera- with a few notable individual exceptions, only ture in the fields of physical and biological as an off-duty pastime. The reason is not far oceanography has accumulated that is not to seek. It is far less important to examine the readily accessible to the nonprofessional stu- ecology of organisms at the next highest level dent of seabirds and not as widely understood of the food chain to the ones that are the pri- by career seabird ornithologists as it should mary concern than it is to examine the next be. This literature in oceanography and lowest level (the food of the fishes or, in the marine fisheries is as extensive in Russian and case of phytoplankton, the physical and Japanese together as in the main languages of chemical environment in which the organisms Western Europe combined; this abundance grow best). compounds the problem of becoming familiar Seabirds are at the very top of the marine with it if, as a student of seabirds, one's in- food chain, and they are not wholly aquatic in terest in the literature is initially somewhat any case since they mainly travel through the marginal. Nevertheless, to achieve the best air rather than the water and reproduce on possible appreciation of the oceanographic inland rather than in the sea. Only with the rela- fluences affecting seabirds, particularly in the tively recent recognition that seabirds con- north Pacific Ocean and its adjacent embay- tribute to the recycUng of nutrients back into ment seas, it is necessary to make the effort. the ocean to an important degree, have sea- Because of the rigor of carrying out their birds gained a new scientific constituency. primary duties while at sea, only a very few At about the same time, governments have North American and European oceanog- begun to recognize that seabirds are rela- raphers or fishery biologists have found time tively easily examined indicators of the pres- to interest themselves in seabirds and then. ence of unseen chemical pollutants in coastal M. T. MYERS

seas, perhaps primarily for the very same rea- significance for seabird ornithology and con- sons that they were previously so largely servation of the rapidly expanding under- ignored; namely, that they are at the top of standing of the oceans, the air-sea interface, the food chains (and so accumulate the most- atmospheric dynamics, and influences upon persistent and least-degradable pollutants) the world's climate of extraterrestrial events. and that the on-land failures in their reproductive biology are readily visible. Small-scale or During the last 10 years, it has become evident that yet another fundamental science is Short-term Influences even more basic to the achievement of a balanced and in-depth understanding of the influ- There is no need to dwell on the well-known ence of the environment upon seabirds—the events that could be mentioned under this combined field of astrophysics, geophysics, heading. Seabird ornithologists are familiar and climatology. New developments in this with the fact that the atmosphere is the field (when they are not published in Nature or medium of seabirds both when searching the Science) appear in journals that are less ocean for feeding areas and when on migra- familiar to seabird ornithologists than those tion, and also a violent enemy, as when par- in which the fishery biologists and biological ticular storms cause occasional "wrecks" of oceanographers publish their findings. seabirds inland from coastlines. As a refine- Unfortunately, important advances in ment of the former, Manikowski of Poland understanding the dynamics and energy suggests that seabirds respond to the passage transport mechanisms of both the atmos- of weather systems, so that their distribution phere and the water masses of the oceans are over the open ocean may be constantly chang- not being picked up by students of seabirds ing. Whereas some species may attempt to because of the natural lag in communication avoid the stormy conditions of low-pressure that occurs between disparate disciplines. areas (cyclonic conditions), others more highly Only in the last few years have oceanog- specialized for exploiting the aerodynamic raphers and climatologists been invited to properties of wind over a moving water sur- address gatherings of ornithologists, and the face may possibly, instead, try to avoid large modesty with which they have sometimes high-pressure regions (anticyclonic conditions done so has limited the impact of their of- with little or no wind). My student, Juan Guz- ferings. man, is attempting to determine whether this At this symposium, it was left to a biologist may be so; if it is, it might be possible, for with no pretentions in either physics or example, to predict some things about the dis- mathematics to demonstrate the need for sea- tribution patterns and population structure of bird ornithologists to understand basic envi- southern hemisphere shearwaters while they ronmental processes well beyond their usual are visiting the oceans of the northern hemi- range of interests. I did so with a series of sphere during the nonbreeding season. slides taken from this "other" literature, and In comparison with the "wrecks" brought I had intended to include in the published ver- about by storms, which are of short duration sion of this paper an extensive bibliography, and not usually very serious, seabird orni- subdivided into category groupings, so that thologists are also familiar with relatively seabird ornithologists could make their own brief and localized disasters caused by selection of the points in the spectrum at changes in the ocean itself. The best-known which they most needed information. example is a slight change in the boundary of Unfortunately, limitations upon space in an ocean current (or other shift in the position this volume, daily additions to the exploding of a distinctive water mass) that results in the literature, and my own inability to keep up failure of food fishes to appear as they nor- with understanding this have forced me to mally would, close to breeding sites of con- omit any references and not to attempt to ex- spicuous colonial seabirds, such as the peri- pound detailed specific physical mechanisms. odic shift in the El Nino off the west coast of Thus unencumbered here, I shall briefly out- South America. A scarcely studied refinement line instead what I perceive to be some of the of this type of event would be the effects of LONG-TERM CLIMATIC AND OCEANOGRAPHIC CYCLES

less-pronounced oceanic changes that might seabirds in the nonbreeding season. These reduce the planktonic food supply of noc- birds may be far from land and hard to study, turnally active, burrow-nesting seabirds. In but what happens during those phases of such instances, the effects might also be a their lives is basic to the composition of the breeding failure for only one or two seasons; colony and condition of the birds when breed- in all probability such events occur, but ing. A start would be to learn everything that whether they are as likely to be detected by us is known and is being discovered about the is problematical. However, the populations of oceans by oceanographers and, thus foremost seabirds are probably already adapted armed, go looking for the seabirds with cer- to survive short-term crises of this type be- tain questions clearly in mind. cause, having long adult Ufe spans, reproductive adults that fail to raise young one year may mostly Uve to succeed in doing so in the Detecting the Effects next or succeeding year, when the oceanic of Long-term Cycles "anomaly" has disappeared. What consti- tutes an "anomaly" will be considered again A scientist's working life lasts only a few shortly. decades, and few studies of seabirds by a A third critical condition for seabirds may single author or agency have been continued be local or widespread, temporary or final, or for longer than 5-10 years on any one prob- some combination of these. A single local lem. Further, while we as individuals may hve spill, or outfall, of a chemical pollutant will be to be equally active in a certain field of re- short term if we can take steps to alleviate the search 20 years hence, our collective con- consequences or stem the flow. Alternately, science and collective muscle consist of we may consider it to be long term if we take several levels of government that tend to ex- the view that it is one additional act of vio- hibit 4- or 5-year changes of direction and lence resulting from the "progress" of Indus- priorities. Certainly, the civil service may live trial Man, and that it is never going to shift on as an inertial recorder of collective experi- into reverse gear. We may say that the effect ence. Certainly, too, those who Uve under one on seabird populations of spills of oil products form or another of dictatorship or, as in some or chemical pollutants in coastal waters of a Canadian provinces, where conservative pat- region will be a "final solution" for any that terns of voting occur, may experience a conti- become wholly extinct before the oil wells go nuity of research and development and con- dry or the industries fail. On the other hand, servation pohcies that exceed the 4- to 5-year the effect will have been merely a perturba- turnaround pattern that is most common. tion of the population if the species survives Yet, even these more continuous systems may and outlives these activities. Recent upturns come to an end quite suddenly because of eco- in populations of peregrine falcons (Falco nomic or pohtical happenstance. peregrinus) and pelicans {Pelecanus sp.) in cer- The point of this digression is to show that tain places where environmental controls seabird ornithologists must not rely on gov- have been enacted give us hope that crises of ernment programs to provide continuous data several years' duration can be withstood by at over a long period of years—not, at least, in least those species that once were common in most countries. Monitoring the biological cir- relation to their respective food sources or cumstances of seabirds is not the same as re- available safe breeding habitats. The really cording the temperature regularly by machine critical features to document are the means at a weather station, since this activity is un- whereby abandoned breeding sites are reoccu- likely to be terminated unless the society col- pied and the time it takes. lapses altogether. We may know that in some It must never be forgotten that we know al- countries the amateur naturalist exists in most nothing about the ecology of subadult or such numbers that records of seabirds will nonreproductive adult seabirds during the continue to be made whatever the circum- years they are at sea unconfined by member- stances. Nevertheless, planning of censuses ship in a breeding unit and that we know al- that will be repeated every 10 years is best as- most nothing about the activities of pelagic sured if government and career biologists M. T. MYERS

combine with the amateur element, so that and each pole. The outcome is zonal winds, any one of them can continue the work if any such as the trade winds and the westerlies. other element should be incapacitated. At any However, as the influence of the sun on the at- one time, either the amateur or the govern- mosphere is variable, the input of heat and the ment or the university personnel may be the extent of the major high-pressure areas vary, prime mover, and each of these forms now as does the path of the jet stream. The recent exists in various countries. droughts in northern Africa and unusually What the scientific Uterature in the fields of heavy rains in AustraUa are both linked to a the geophysical, atmospheric, and oceano- southward shift of the Intertropical Conver- graphic discipUnes demonstrates is that natu- gence Zone in the atmosphere and a "corruga- ral cUmatic oscillations probably range in tion" of the wind circulation from a more nor- length from the 11 -year sunspot cycle through mal zonal (latitudinal) path. These shifts in several decades (or a human lifetime) to the atmospheric circulation are almost cer- several hundred years. So, when our children tainly transmitted also to the ocean currents are the new trustees of seabird colonies 20 or and the marine ecosystem, with the influence 40 years hence, they must interpret their data being felt for a long period of years. using the full range of physical as well as bio- One of the oceanic domains of the North logical data that we can leave for them. In- Pacific is the transitional domain, which Ues deed, the information is, I beUeve, already east-west where the West Wind Drift im- available over a long enough period (since pinges upon the coasts of British Columbia 1940 at least) to allow some speculative inter- and Washington State. It is precisely in this pretations of what may have been happening sector that there was a well-documented to our seabird populations, whether or not we "temperature anomaly" in 1957-58. Since an knew or had any evidence of it. anomaly implies something completely out of

I have already suggested that extraterres- the ordinary, I seriously question the appro- trial events, particularly the 11 -year sunspot priateness of the term for an event that may cycle, are increasingly believed to influence or may not be recurrent (at the time it was a the atmosphere of this planet. The Chinese pronounced variation from the oceanographic and Japanese have remarkably precise rec- records accumulated up to that time, but the ords of the northern limits of certain agricul- period had not been a very long one). It is no tural crops at particular times, the phenology coincidence that the numbers of albatrosses of flowering, and the freezing of lakes. These recorded at Ocean Weather Station "Papa" demonstrate long-term trends in overall cU- was higher during this warmwater "anomaly" mate in eastern Asia that extend over hun- than subsequently (indeed, an 18-year record dreds of years. The chmate of Japan is influ- of the seabirds recorded at "Papa" also ex- enced by the high-pressure area in winter over hibits other interesting fluctuations from the mainland East Asia. There is evidence that base-Une data in certain years). severe ice conditions in the Bering Sea during Recent analyses of sediments from off the the early 1970's may have been due to an east- coast of California have demonstrated long- ward shifting of this high-pressure area. term fluctuations in sardine populations ex- Again, the water mass of the Kuroshio Exten- tending back at least 1,800 years, with in- sion and the West Wind Drift takes several creases lasting 20-150 years and spaced years to travel across the Pacific Ocean, and 20-200 years apart. The number of anchovies there is an established temperature variation declined steadily. Yet until now. El Nino that travels like a slow wave with it. Off events have been treated as anomalies in that Japan, the Kuroshio Current periodically de- region as well as off the coast of Peru. Just as velops meanders which slow the speed of the we recognize that different species of fish fol- eastward flow. Cold and warm "pools" of low the warm water north on such occasions, water approach the west coast of Canada and we must also recognize the rather distinct sea- the western United States from time to time. bird species assemblage that is trapped, as it Ocean currents are driven by the atmos- were, in the Gulf of CaUfornia. Clearly, like pheric motion above them, which consists of the termination point of the West Wind Drift several convective cells between the equator at about the 45-55° parallel, the coast of Baja LONG-TERM CLIMATIC AND OCEANOGRAPHIC CYCLES

California and southern California State, from Conclusions the 25-35° parallel where the California Cur- rent begins to swing away from the coast to the west as the North Equatorial Current, is We know little of the accuracy of censuses another zone of instability. of seabird numbers made between 1850 and I think that it is no accident that the south- 1950. There has been a tendency to assume ern limit of several northern species of North that numbers of seabirds at long-established Pacific seabirds ends in southeastern Alaska colonies have been relatively unchanging, or northern British Columbia, and that the even though the expansion of some species northern limit of the ranges of several other into previously unrecorded breeding sites in species occurs in Washington State or south- low numbers is well documented. Contraction ern British Columbia. Indeed, the west coast of breeding ranges, likewise, has most com- of Vancouver Island is not rich in species, and monly been attributed to the influence of man. several of those that exist are not present in Recent literature from the physical sciences, great numbers. This is a region of rather more on the contrary, suggests that seabird num- variable conditions than elsewhere, and bers at particular colonies are most unlikely species evidently find that it is difficult to to have been stable for any great length of colonize and it quickly becomes unsuitable time, at least at high or middle latitudes and again. Since 1940, indeed, there has been a particularly at points where boundaries be- parallel decline in the annual mean sea-surface tween currents impinge on continental coasts. temperature at a number of coastal recording Indeed, some early estimates of colony sizes stations in British Columbia, and this seems may not have been as much in error as we may to have been a rebound from a less well-docu- have assumed, neither when apparently too mented rise in sea-surface temperatures dur- large nor when apparently unlocated by pre- ing the 20 years before that, which culminated vious visitors. in a peak around 1940. Sahnity has Ukewise The halving of a large colony over a period trended downwards during the last 30 years. of 20 to 50 years in the middle of the range of The seabird colony size data before 1960 are a species and the establishment and disap- so nonquantitative that it is impossible to be pearance of smaller breeding groups at oppo- sure what changes in seabird populations and site extremes of the range (both latitudinally breeding sites may have taken place in re- and longitudinally), may equally reflect natu- sponse to these physical changes. ral long-term climatic or oceanographic The lesson is that we must now examine all changes and may naturally be reversed at future census and distribution data with some time in the future, perhaps within half a trends in sea-surface temperature and saUnity century. The implication for conservation of in mind as two of several likely factors influ- seabird colonies that are at the contracting encing them. We must no more ignore data end of a species' range is that cultural rather outside our own field than a salmon ecologist than biological criteria may be the best might. determinants.

Sea Ice as a Factor in Seabird Distribution and Ecology in the Beaufort, Chukchi, and Bering Seas

George J. Divoky^

U.S. Fish and Wildlife Service Fairbanks, Alaska

Abstract

Arctic sea ice has a variety of effects on seabirds. Although the decrease in surface area available for feeding and roosting is probably the major restrictive effect, also important are productivity of water covered by ice and the reduced prey abundance in nearshore areas due to ice scour. The most important benefit that sea ice provides to seabirds is the plankton bloom that occurs in the ice in the spring. In the Beaufort and Chukchi seas this bloom supports an under-ice fauna that is an important food source for seabirds.

Sea ice is a major factor in the distribution possible feeding area by half. The effect on and ecology of many of the birds treated in diving species is not as severe since, if open this symposium. Sea ice is defined here as ice water is scattered throughout the ice, diving formed by the freezing of seawater and in- species still have access to much of the prey in cludes both free floating pack ice and the the water column and benthos. When open more stable shorefast ice. Since icebergs are water is scarce, however, diving species can composed of ice of land origin, they are not become concentrated in the available water, discussed. resulting in intense competition for available Before discussing the specific relationship prey. In certain situations the open water is of birds and sea ice in the Beaufort, Chukchi, used only as a migratory pathway, but open and Bering seas, I hst the general effects that water is necessary for birds that must roost or arctic ice can have on seabirds. For purposes feed. of discussion these effects can be divided into negative effects, or disadvantages, and posi- Sea Ice Reduces Primary Productivity tive effects, or advantages. in the Water Column

General Effects of Ice inhibits phytoplankton blooms in the Ice on Birds water column, thus decreasing the biological productivity of ice-covered waters. This inhi- Negative Effects bition occurs in two ways: • By decreasing light penetration of the Sea Ice Decreases the Surface Area of Water water column.— Mxich. of the sunlight reaching The decrease in the surface area of water is the ice is reflected by the ice and by snow on the simplest and most immediate effect that the ice. The amount of Ught reaching the sea ice has on birds. Ice acts as a barrier that water depends on the angle of the light, thick- restricts the availability of food in the water. ness of ice, and amount of snow cover. When Surface feeders are the most severely affected the layer of under-ice algae forms, it absorbs since, in general, ice cover of 50% reduces the light and further reduces the amount of light 'Present address: Point Reyes Bird Observatory, reaching the water (Bunt 1963). This reduc-

4990 State Route 1, Stinson Beach, California tion in light reduces the depth of the euphotic 94970. zone. 10 G. J. DIVOKY

• By increasing the stability of the water rated from the mainland by open water but coZumn.— Increased stability of the water are adjacent to the pack ice. column reduces the upwelling of nutrient-rich waters into the euphotic zone. Ice stabilizes the water column primarily by preventing Advantages wind-driven movement of surface waters and Sea Ice Provides a Matrix and by forming a layer of meltwater at the surface Substrate for an Ice-associated Plankton in the spring and summer (Dunbar 1968). Bloom and an Associated Under-ice Fauna

The first detailed studies on the blooms of Ice Benthic and Sea Reduces diatoms that occur in the lower levels of ice Intertidal Biota were done by Appollonio (1961). The impor- Benthic flora and fauna can be reduced by tance of this bloom in the energy budgets of the presence of ice in two ways: In shallow arctic and subarctic seas has only recently water ice can freeze to the bottom for much of been realized (Alexander 1974; McRoy and the year and prevent the estabUshment of Goering 1974). In areas where ice is present plant and animal populations; and when ice throughout the year, the plankton bloom sup- floes are pushed together, they form under- ports a population of under-ice invertebrates. water ice keels that can scour the bottom These populations have been little studied but when the ice moves. Both of these events not apparently consist primarily of copepods and only act directly to decrease benthic popula- amphipods (Mohr and Geiger 1968). Feeding tions but also disturb the sediment, making it on the invertebrates associated with the ice less suitable for colonization. In areas with are two species of fish, polar cod (Arctogadus heavy ice scour, sessile benthic populations glacialis) and arctic cod {Boreogadus saida). can be greatly reduced, although motile Andriashev (1968) used the term cryopelagic species may move into scoured areas during to describe such fish, which are found in the the ice-free period in summer. In addition to mid-water zone but also are associated with preventing the establishment of sessile ice during some part of their life cycle. benthic animal populations, ice scour also pre- The underside of multi-year ice has vents the estabUshment of beds of kelp and numerous ridges and pockets that provide a eelgrass {Zostera marina), thus decreasing the heterogeneous environment for the under-ice diversity and productivity of arctic inshore fauna. This environment is protected from waters. Both kelp and eelgrass beds are im- disturbance from currents and wave action by portant feeding sites for birds in areas south ice keels acting as barriers, which also provide of the region affected by ice scour. shelter from predators in the same manner as a coral reef. The overall effect of the under-ice Sea Ice Allows Terrestrial Predators flora and fauna is to increase the diversity of Access to Breeding Sites surface waters in arctic seas by creating an in- verted benthic biota. The formation of ice between the mainland and offshore islands allows the arctic fox (Alo- Sea Ice Provides Hauling Out pex lagopus) and other predators access to the Space for Marine Mammals islands used by breeding birds. Foxes can become permanently established on islands that The mammals that inhabit the ice in the have food sources during the period when Chukchi and Bering seas and their adapta- birds are absent from the island. Often, how- tions to the pack ice environment were discussed of these species ever, there is Uttle to attract foxes to the is- by Fay (1974). Many lands other than breeding birds. Because frequently haul out on the ice, where they pro- moats form around many islands before the vide food in the form of feces, placentas, and breeding birds arrive, foxes are primarily a carcasses. problem when moat formation is incomplete Sea Ice Provides Roosting Sites or when the breakup of ice is late. Arctic foxes are found on the pack ice throughout the sum- Ice provides a hard substrate that allows mer and thus can visit islands that are sepa- seabirds to leave the water to roost. This SEA ICE AS A FACTOR IN SEABIRD DISTRIBUTION 11

allows such species as the Larus gulls, which billed murre (U. lomvia) occur throughout the typically roost on hard substrates, to occur in winter (Swartz 1967). It is likely that black large numbers well offshore. guillemots are also found in this area. The lack of chronic lead systems in the Sea Ice Reduces Wind Chill Beaufort Sea precludes the presence of win- that The unevenness of the upper surface of the tering seabirds. The one species may be found wintering in the Beaufort is the Ross' ice reduces the speed of winds directly over gull (Rhodostethia rosea). Ross' gull is be- the ice, thus providing a microhabitat and re- lieved to winter primarily in the Arctic Ocean ducing the amount of wind chill for birds sit- (Bailey 1948). The number of sightings that ting on and next to the ice. have been obtained in both the eastern and Sea Ice Decreases Wave Action western Arctic indicate that the species may winter over much of the Arctic Ocean. It may Ice floating on the water reduces the sur- thus be expected to occur in both the Chukchi face disturbance of the water. Although and Beaufort seas during winter. swells pass through areas with much ice Ice cover—not prey abundance—plays the cover, waves do not. In addition, surface major role in severely Umiting bird numbers waters on the lee side of ice floes and cakes in the Arctic Ocean in winter. Prey is known usually have little surface disturbance. Sur- to be abundant in parts of the Arctic Ocean face feeders may be able to locate prey more during the period of ice cover. In the Chukchi easily because of these reductions in surface Sea, Eskimos fishing through the ice can disturbance. catch 23 kg of arctic cod per person per day (D. C. Foote, unpubhshed data). Eskimos jig Specific Effects of Ice for the fish at considerable depths, and the on Birds in the cod do not appear to be as common directly Western Arctic below the ice as they are in summer. The effects of new ice (which forms on the underside The retreat of the pack ice each spring and of the ice during the winter) on the under-ice the formation of ice each fall greatly af- new fauna are not known. The abundance of am- fect a large area of the Arctic Ocean off the phipods in ice-covered waters in winter is of and of the Bering Sea. coast Alaska much demonstrated by the experience of the Specific in which birds are affected by ways Greeley Expedition in the eastern arctic. They ice in the western Arctic are discussed on a discovered that any scrap of food thrown into All observations are own, seasonal basis. my a lead was quickly consumed by amphipods. unless otherwise stated. Nets were made to catch the amphipods and the availability of this food source played a Winter major part in the survival of the expedition (Schmitt 1965). Chukchi and Beaufort Seas Aside from the food found in leads in the From late November to mid- April, ice cover ice, the only food available to birds in the of the Chukchi and Beaufort seas is almost Beaufort and Chukchi seas in winter is carrion complete. The only areas where birds can be and the feces of mammals found on the pack expected to winter in these seas are the ice. The presence of the arctic foxes on the chronic lead systems. Such lead systems are pack ice during the winter demonstrates the found off Wainwright and Point Barrow and availabiUty of scavenging opportunities on south of the Point Hope-Cape Thompson the ice. Arctic foxes on the pack ice Uve on area (Shapiro and Burns 1975). Only the black feces and the remains of seals killed by polar guillemot {Cepphus grylle) is knoAvn to regu- bears (Urus maritimus). Polar bear and seals larly winter offshore from Wainwright and are both common in the Beaufort and Chukchi Point Barrow (Gabrielson and Lincoln 1959; seas in winter, but no scavenging seabirds are Nelson 1969). In the Point Hope-Cape Thomp- found there in the winter. It was thought that son area, glaucous gulls (Larus hyperboreus), the ivory gull {Pagaphila eburnea) was asso- the common murre {Uria aalge), and the thick- ciated with marine mammals during the win- 12 G. J. DIVOKY

ter, but they are now known to winter at the duction (0.29 mg C/m^ per h), and that in the Bering Sea ice edge, where they feed on fish water south of the ice is lower yet. At this and crustaceans (Divoky 1976). The only birds time production within the ice is very high associated with polar bear kills in the Chukchi (more than 5 mg C/m^ per h) (McRoy and Sea in March are ravens, Corvus corax (T. J. Goering 1974). Because this phytoplankton Ely, Jr., personal communication). bloom is trapped in the ice, it is not available to grazers. Thus, before the spring melt the ice front is the only area where a large quantity of phytoplankton is available to higher Bering Sea levels of the marine food chain. Ice begins to cover the northern Bering Sea The winter distribution of birds in the in November and reaches its by maximum Bering Sea correlates well with the findings February, when it usually extends as far on primary productivity. Densities south of south as the edge of the continental shelf, and the ice and the continental shelf average less covers nearly 75% of the surface of the Bering than 10 birds/km". At the ice front during one Sea (Lisityn 1969). Coverage can vary greatly cruise in March, densities exceeded 500 from year to year. In certain years Bristol birds/km^ Densities at the ice front increase Bay may be completely covered and in others from south to north; they drop in the region ice is found only in the northern part of the where the ice front grades into more consoli- Bay. Almost all ice in the Bering Sea is first- dated pack ice, and are less than 0.1 bird/km^ year ice. This ice tends to be flat on the top in the consolidated pack. and underside and in general lacks the extensive keels and pressure ridges found on multi- The most numerous species at the ice front are common and thick-billed murres, which year ice. constitute more than 90% of all birds seen. The Bering Sea ice has a number of large- Irving et al. (1970) were the first to report on scale features of importance to birds. The the large number of murres at the ice front. "front" is a zone of ice south of the consoli- Feeding flocks of 25,000 individuals have dated pack that is composed of small floes, ice been observed at the front, in which densities pans, and brash ice. This zone is prevented were as high as 10,000 birds/km''. No other from forming large floes by the action of diving species is common at the ice front. The swells from the open water to the south. The parakeet auklet {Cyclorhynchus psittaculus) front continually changes in width: When is seen on most cruises, but only during a winds are from the south, it is compressed small percentage of observation periods and into a narrow band; when winds are from the always in low numbers. Black guillemots are north, it is a broad zone composed of bands of common north of the ice front and stragglers ice interspersed with open water. are occasionally seen at the front. Pigeon Polynias (areas of open water) are found im- guillemots {Cepphus columbus), least auklets mediately south of the large islands in the {Aethia pusilla), and crested auklets {A. crista- northern Bering Sea. They are formed by the tella) are irregular visitors to the front. southward movement of ice caused by the prevailing winds. This movement causes ice to be Surface feeding species commonly found at pushed away from the south side of islands, the ice front include the northern fulmar [Ful- leaving areas of open water. Large polynias marus glacialis) and five species of gulls. The are associated with St. Lawrence, St. fulmar is common south of the ice and is Matthew, and Nunivak islands and with the found only in the southern portion of the south side of the Seward Peninsula (Shapiro front. Three species of Larus are found at the and Burns 1975). ice front. The most common is the glaucous- The most biologically active area of the winged gull (Larus glaucescens); the glau- Bering Sea in winter is the ice front. Studies cous gull is less frequently seen. The slaty- of primary productivity in April show that backed gull (L. schistisagus), a species that production at the surface in the ice front is breeds in Asia, is most common west of St. high (1.98 mg C/m' per h). Surface waters di- Matthew Island (McRoy et al. 1971). The rectly under the pack ice have much lower pro- black-legged kittiwake (Rissa tridactyla) is SEA ICE AS A FACTOR IN SEABIRD DISTRIBUTION 13

common in open water south of the ice but is mots. A severe winter in the White Sea in also found throughout the entire width of the 1965-66 decreased the amount of open water front. The ivory gull is unique in that it is and caused an increased black guillemot mor- found only at the ice front in winter. In addi- taUty (Bianchi and Karpovitsch 1969). On a tion to these species, the fork-tailed storm- windless day in March I conducted bird obser- petrel (Oceanodroma furcata) is a regular but vations in the Bering Sea ice where no leads or uncommon visitor to the ice front in winter. open water were encountered. The only bird Densities of surface feeding species at the ice seen was a black guillemot flying over the ice. front are low when compared to the high den- In situations such as this, where black guille- sities of murres, and do not regularly exceed mots are prospecting for open water, they 10 birds/km^ may use the "water sky" and steam fog associated with leads as visual aids. "Water sky" The primary food consumed by birds at the is the reflection of the dark water in the clouds ice front is pollock (Theragra chalcogramma). over the lead, and contrasts sharply with the An amphipod {Parathemisto libellula) and the "ice sky." The presence of "water sky" allows euphausiids are less important. Examination birds to detect open water from a distance of of the stomach contents of birds and fish many miles. show that large feeding flocks are usually as- Aside from birds found in and near island- sociated with schools of pollock feeding on P. associated polynias, only murres and black libellula and euphausiids. guillemots are regularly found on the consoU- The habitat of the consolidated pack in the dated pack ice in winter. Bering Sea is markedly different from that at The polynia associated with islands in the the ice front. Whereas the front is charac- consolidated pack provide refuge(s) for sea- terized by bands of ice interspersed with open birds. Fay and Cade (1959) found the polynias water and ice coverage rarely exceeding 4 south of St. Lawrence to be most important to oktas (4/8), the consolidated pack consists pri- oldsquaws (Clangula hyemalis). King eiders marily of large expanses of unbroken ice. {Somateria spectabilis), common eiders {S. Small leads are formed by the shifting of the mollisima), and oldsquaws are common in the ice caused by currents and wind. Ice coverage St. Matthew Island polynias (McRoy et al. is usually 7 to 8 oktas. The southern part of 1971). Because these polynias are in shallow- the consolidated pack, which grades into the water areas, they provide feeding opportu- ice front, has frequent leads. Most of the nities for benthic feeding species. species found at the ice front can be found in the southern part of the consolidated pack, but murres are most common. Their numbers Spring- decrease, however, in the more northerly Chukchi and Beaufort Seas pack, where leads are less frequent. Black guillemots, in contrast, increase with increas- In April and May a lead system develops ing ice cover, and reach their greatest abun- from the Bering Strait north to Cape Lisburne dance in the small leads constantly forming and then northeast to Point Barrow. The lead and refreezing deep within the ice. Because is a flaw lead that occurs between the shore- they exploit this habitat, they are dependent fast ice and the free-floating pack. It is a on the formation of lead systems. I have often major migration route for a number of species seen leads a quarter mile wide refrozen to the of birds, primarily eiders. East of Point Bar- point where new ice covered all but a small row in the Beaufort Sea, no similar well-de- patch of open water; black guillemots were fined large lead exists. Consequently, there is frequently crowded into this open water. Be- a greater chance of bird mortaUty occurring in fore the lead closes completely the guillemots the Beaufort Sea than in the Chukchi Sea be- must fly to an open lead. When winds are light cause the early migrants are unable to find and temperatures low, lead systems fail to open water. In 1960, 10% of all the king eiders form as rapidly as usual, and when they do that migrate through the Beaufort Sea died they refreeze quickly, causing a loss of the during a late freeze (Barry 1968). Additional preferred habitat of wintering black guille- records of eider mortaUty due to late breakup 14 G. J. DIVOKY

or sudden freezes were presented by Palmer of breeding may be delayed at northern (1976). Bering Sea colonies and for some tundra In late May, rivers that empty into the species. northern Chukchi and Beaufort seas begin to At the time of decomposition the large flow. The shorefast ice is still present at this standing stock of phytOplankton present in time and the rivers flow over the ice. For large the pack ice is released into the water. No in- rivers, such as the Colville and the Saga- formation is available on fish and invertebrate vanirktok, the area of ice covered by water is populations that are associated with the de- considerable. Openings in the ice develop composing ice. The quantity of organic carbon sometime after the river runoff starts and the released is considerable, although it is not river water drains through the ice. known what fish or invertebrate populations This river overflow plays an important role are supported by this plankton as soon as it is in the breeding biology of certain island nest- released. For birds breeding in areas where ice ing species, since the overflow surrounds is- is present in the initial stages of breeding, the lands and prevents arctic foxes from reaching phytoplankton released by the disintegrating the islands. The overflow also allows birds to ice could play an important part in the birds' sit in the water near breeding sites. It is not energy budgets. known whether river overflow contains prey items available to birds. After the overflow drains through the ice, the shorefast ice that Summer has been covered with river overflow decom- Chukchi and Beaufort Seas poses quickly, and patches of open water occur early in areas just seaward of major In the northern Chukchi and Beaufort seas river deltas. For this reason the largest breed- the nearshore marine environment is domi- ing colonies on barrier islands in the northern nated by sea ice in June and July. In June the Chukchi and Beaufort seas are all found near coastal areas are characterized by a snow-free the mouths of large rivers. Islands away from tundra teeming with nesting waterfowl and rivers become isolated from the pack ice by shorebirds next to an expanse of sea ice al- moats, which are caused by the absorption of most completely devoid of bird life. In areas solar radiation by the islands and the melting where river outflow does not occur, the use of of the ice immediately adjacent to them. Moat nearshore waters usually begins when a moat formation is not as predictable and uniform as forms along the shoreUne. Amphipods and river overflow. other invertebrates are found in this moat, especially at stream mouths. Limited but regular use of the moat occurs, primarily by Bering Sea loons (Gavia spp.), oldsquaws, and arctic When the ice in the Bering Sea begins to terns (Sterna paradisaea). melt in April, the edge of the pack does not re- As the snow on top of the shorefast ice be- cede northward as is frequently thought. gins to melt, ponds form on top of the ice. As Rather, there is a general decomposition of ice melt proceeds, these melt ponds merge into throughout the pack. The leads that are con- long, parallel channels and may cover well stantly forming in the ice no longer freeze. As over 50% of the ice surface. Only when thaw melt continues and ice becomes rotten, leads holes form and the melt ponds are connected form with increasing frequency. This manner to the water under the ice is food present in of ice decomposition is important to birds. the channels. Amphipods are then seen swim- The leads that form deep in the pack ice pro- ming in these channels. Bird use of these vide feeding and roosting areas near the large channels is not extensive. seabird colonies found north of the ice edge, It is usually late July before the nearshore and are used by certain tundra-nesting ocean ice begins its rapid decomposition. Ice in the migrants such as eiders, red phalaropes lagoons is the first to melt. Ice seaward of the (Phalaropus fulicarius), and jaegers {Sterco- barrier islands decomposes more slowly be- rarius spp.). If ice decomposition is retarded cause of the presence of keels and pressure by persistent low temperatures, the initiation ridges. As the ice melts, the in-ice algal bloom SEA ICE AS A FACTOR IN SEABIRD DISTRIBUTION 15

is released into the water. These algae are im- cipal species encountered on the ice are the portant because they provide at least 25 to black-legged kittiwake and the thick-billed 30% of the productivity in coastal waters and murre. In the Beaufort, red phalaropes, old- allow the biological growing season to begin squaws, and glaucous gulls are the most com- before the open-water plankton bloom occurs mon species. (Alexander 1974). In nearshore areas close to Numerous arctic cod are associated with Barrow, large populations of mysids and am- the underside of the sunomer pack ice. Ship- phipods are associated with the decomposing board censusing in the ice is complicated ice. At least in certain areas, these ice-asso- when cod are stranded on ice floes, as the ice ciated zooplankton populations are a major shifts under the weight of the ship. Gulls, arc- food source for nearshore migrants, especially tic terns, and jaegers gather behind the ship red phalaropes, arctic terns, and Sabine's to feed on these fish; mixed flocks of more gulls (Xema sabini). than 100 birds are common. In the absence of The effects of ice scour on the shoreline and a ship to provide the disturbance needed to the nearshore bottom of the Chukchi and make large numbers of cod available, these Beaufort seas is demonstrated by the absence birds are dependent on locating the fish in the of sessile benthic fauna and flora. The effect surface waters next to ice floes. Because cod this absence has on birds is seen in the feeding frequently swim over underwater ice shelves habits of nearshore birds. Oldsquaws and they are highly visible from above and should eiders, which frequently feed on molluscs, feed be easily accessible to aerial feeders. instead on motile benthos species such as mysids, amphipods, and isopods. The emperor goose {Philacte canagica) is absent from the Fall northern Chukchi and Beaufort seas, ap- Chukchi and Beaufort parently due to the absence of eelgrass beds. Seas Ice scour is the major cause of the absence of By the time ice formation begins in late Sep- eelgrass in northern Alaska (C. P. McRoy, tember or early October, most seabirds have personal communication). left the Arctic on their southward migration. The offshore ice in the Chukchi decomposes The principal exception is the oldsquaw, more rapidly than that in the Beaufort, which does not begin its migration until Sep- largely because Bering Sea water enters the tember. Some oldsquaws remain in nearshore Chukchi through the Bering Strait (Coach- waters until they are driven out by the forma- man and Barnes 1961). By late July the Chuk- tion of new ice. In contrast to the spring mor- chi is usually ice free as far north as Icy Cape. tality, there are few records of extensive bird In the Beaufort, however, ice decomposition mortality in the fall due to lack of open water. occurs slowly through June and July, and One instance was reported for 1975, when only in August does a definite strip of open nearshore waters froze early and flightless water develop between the shore and the edge eiders were seen sitting on the ice near Pt. Lay of the pack ice. The amount of open water in the Chukchi Sea. The birds were in a varies greatly from year to year. In certain weakened condition, apparently due to their years the Beaufort is not navigable due to the inability to obtain food (W. J. Wiseman, per- lack of open water. sonal conmiurtication). Aerial censusing in June and July shows In the offshore waters the species asso- that bird densities on the offshore ice are ex- ciated with the pack ice in September are the tremely low. In August and September, when same as those in August. In late September, shipboard censusing can be conducted, densi- however, ivory and Ross' gulls become the ties on the pack ice in both seas are about 10 most common species at the ice edge in the birds/km^ Unlike the Bering Sea, where densi- Chukchi. Glaucous gulls and black guillemots ties south of the ice are much less than on the are also associated with the advancing ice ice, bird densities south of the ice in the Beau- edge (Watson and Divoky 1972). Except for fort and Chukchi seas are slightly higher in the Ross' gull, which apparently winters in the open water south of the ice, averaging the arctic basin, these species remain with the about 20 birds/km^ In the Chukchi the prin- ice as it advances into the Bering Sea. 16 G. J. DIVOKY

Bering Sea numbers of seabirds are regularly found in the summer pack ice feeding on arctic cod and Little is known about bird distribution in zooplankton associated with the ice, bird den- the Bering Sea during ice formation because sities south of the ice are usually greater than cruises in rapidly forming ice are potentially those in the ice. The only species that appear hazardous. It is not known if the large num- to depend on the ice-associated fauna for bers of birds found at the ice edge in March much of their food are the three pagophihc are present in December and January. species mentioned above. Discussion

The principal effect of the arctic pack ice is References to lower biological productivity and bird densities in the areas it covers. Unlike the antarc- Alexander, V. 1974. Primary productivity regimes tic pack ice, which supports a large biomass of of the nearshore Beaufort Sea, with reference to potential roles of ice biota. Pages 609-632 in pagophilic species, the number of pagophihc J. C. Reed and J. E. Sater, eds. The coast and shelf of species supported by the arctic pack ice is the Beaufort Sea. Arctic Institute of North small. Only the ivory gull, Ross' gull, and America, Arlington, Virginia. black guillemot have specific adaptations to Andriashev, A. P. 1968. The problem of the life the ice environment. The Ross' gull and guille- community associated with the antarctic fast ice. Pages 147-155 in R. I. Currie, ed. Symposium on mot winter in the pack ice, and the ivory gull antarctic oceanography. Scott Polar Research In- is associated with ice year. throughout the stitute, Cambridge. The total biomass of these species is low. AppoUonio, S. 1961. The chlorophyll content of arc- Other species which are regularly associated tic sea ice. Arctic 14:197-200. with the arctic pack, such as murres and Bailey, A. M. 1948. Birds of arctic Alaska. Colo. Mus. Nat. Hist. Popular Ser. 8. 317 pp. black-legged kittiwakes, are also found in Barry, T. W. 1968. Observations on natural mor- large numbers away from the ice. In addition, tality and native use of eider ducks along the these species are usually associated with ice Beaufort Sea coast. Can. Field-Nat. 82(2): 140- for Umited periods during the year—murres 144. Bianchi, V. V., and V. N. Karpovitsch. 1969. The in- primarily in winter and spring and kittiwakes fluence of abnormal ice-cover of the White Sea primarily in summer. and Murman in 1966 upon birds and mammals. The difference in the antarctic and arctic (In Russian, English summary.) Zool. Zh. pack ice systems is largely due to the antarc- 48(6):871-875. Bunt, J. S. 1963. Diatoms of antarctic sea ice as tic pack ice being surrounded by ocean, where- agents of primary production. Nature (Lond.) as the arctic pack ice is, in general, sur- 199:1255-1257. rounded by land. The high productivity asso- Coachman, L. K., and C. A. Barnes. 1961. The con- ciated with the antarctic pack ice is due pri- tribution of Bering Sea water to the Arctic marily to the mixing that occurs at the edge Ocean. Arctic 15:147-161. Divoky, G. J. 1976. The pelagic feeding habits of of the pack ice. There is little opportunity for Ivory and Ross' Gulls. Condor 78:85-90. mixing to occur next to the arctic pack ice, ex- Dunbar, M. J. 1968. Ecological development in cept where it is next to large expanses of polar regions: a study in evolution. Prentice-Hall, boreal waters. This occurs in the Bering Sea in Englewood Cliffs, N.J. 119 pp. Fay, F. H. 1974. The role of ice in the ecology of winter and spring, in the North Atlantic, and marine mammals of the Bering Sea. Pages 383- to a minor extent in the Chukchi Sea in sum- 399 in D. W. Hood and E. J. Kelly, eds. Oceanog- mer and fall (Dunbar 1968). The limited geo- raphy of the Bering Sea. Univ. Alaska Inst. Mar. graphic range and seasonal nature of high pro- Sci. Occas. Publ. 2. Fay, ductivity at the arctic pack ice edge has been F. H., and T. J. Cade. 1959. An ecological analysis of the avifauna of St. Lawrence Island, a major factor in preventing a well-developed Alaska. Univ. Calif. Publ. Zool. 63:73-150. pagophilic avifauna. Gabrielson, I. N., and F. C. Lincoln. 1959. The birds The importance of the in-ice algal bloom and of Alaska. The Stackpole Company, Harrisburg, its associated under-ice fauna is not yet clear. Pennsylvania, and Wildlife Management Insti- tute, Washington, D.C. 922 It is probably most important in areas such as pp. Irving, L., C. P. McRoy, and J. J. Burns. 1970. the Beaufort Sea, where productivity in the Birds observed during a cruise in the ice-covered water column is low. Although considerable Bering Sea in March 1968. Condor 72:110-112. SEA ICE AS A FACTOR IN SEABIRD DISTRIBUTION 17

Lisityn, A. P. 1969. Recent sedimentation in the Nelson, R. K. 1969. Hunters of the northern ice. Bering Sea (Transl. from Russian.) Israel Pro- University of Chicago Press, Chicago, 111. 429 pp. gram for Scientific Translations, Jerusalem. Palmer, R. S. 1976. Handbook of North American 614 pp. birds. Vol. 3. Yale University Press, New Haven, McRoy, C. P., and S. R. Goering. 1974. The influ- Conn. 560 pp. ence of ice on the primary productivity of the Schmitt, W. L. 1965. Crustaceans. University of Bering Sea. Pages 403-421 in D. W. Hood and Michigan Press, Ann Arbor. 204 pp. E. J. Kelly, eds. Oceanography of the Bering Sea. Shapiro, L. H., and J. J. Burns. 1975. Major late- Univ. Alaska Inst. Mar. Sci. Occas. Publ. 2 winter features of ice in northern Bering and McRoy, C. P., S. W. Stoker, G. E. HaU, and E. Chukchi seas as determined from satellite Muktoyuk. 1971. Winter observations of mam- imagery. Univ. Alaska Geophys. Inst. Rep. 75-78. mals and birds, St. Matthew Island. Arctic 24:63- 65. Swartz, L. G. 1967. Distribution and movements of Mohr. J. L., and S. R. Geiger. 1968. Arctic Basin birds in the Bering and Chukchi seas. Pacific Sci. faunal precis-animals taken mainly from arctic 21:332-347. drifting stations and their significance for bio- Watson, G. E., and G. J. Divoky. 1972. Pelagic bird geography and water-mass recognition. Pages and mammal observations in the eastern Chukchi 297-313 in J. E. Sater, coordinator. Arctic drift- Sea, early fall 1970. U.S. Coast Guard Oceanogr. ing stations. Arctic Institute of North America. Rep. 50:111-172.

STATUS OF MARINE BIRD POPULATIONS

Distribution and Status of Marine Birds Breeding Along the Coasts of the Chukchi and Bering Seas

James C. Bartonek^

U.S. Fish and Wildlife Service Fairbanks, Alaska and Spencer G. Sealy University of Manitoba Winnipeg, Manitoba, Canada

Abstract

The Alaska coast fronting on the Chukchi and Bering seas, exclusive of the Aleutian Islands, supports seven complexes of marine bird colonies numbering more than 1 million birds each, nine colonies of 100,000 to almost 1 million birds, and many smaller colonies. Colonies are found on most headlands and islands and are dominated numerically by alcids and kittiwakes (Rissa sp.). Estuarine habitats (mainly the lowlands of northern Seward Peninsula, Yukon-Kuskokwim delta, and the north side of the Alaska Peninsula) are extremely important for breeding and migrating marine waterfowl, shorebirds, gulls (Larus sp.), and terns (Sterna sp.). Information on population size and distribution of breeding marine birds within this area is extensive for only a few of the more heavily hunted species of waterfowl. Except for the intensive and systematic censusing of a few colonies in this region, population data on cliff-, burrow-, and crevice-nesting

birds are such that all but gross changes in numbers may go unnoticed, and if noticed they could not be measured.

Habitats for breeding marine birds are mittedly arbitrary, we discuss mainly the found along much of the 4,1 00-km coastline of colonial nesting species because they are Alaska that fronts on the Chukchi and Bering generally in greater jeopardy from lost breed- seas. Seasonal sea ice and an extensive outer ing habitat and from catastrophes than are continental shelf are dominant features that the species that are widely dispersed or soli- contribute to the productivity of these marine tary in nesting. Because we beUeve matters waters, which sustain populations of fishes, affecting the conservation of marine birds will birds, and mammals that are of considerable be geographically oriented, we discuss the and diverse values to man (Kelley and Hood status and distribution of breeding birds on 1974). that basis, rather than by the more tradi- Our purpose in this paper is to describe the tional taxonomic approach. We use the terms distribution, abundance, and relative status "colony" and "colonies" somewhat loosely of some of the nearly 100 species of marine ^^^ interchangeably to include any aggrega- birds , breeding within this region and the in- . f u- j * i-u j-rr 4. c ^. , -. , . , , , , . . tion of bu-ds of the same or different species lormation base from which the descriptions nesting in proximity to each other, even those are derived. Although the selection is ad- on the same island or headland, although populations may be miles apart and occupy

'Present address: U.S. Fish and WUdUfe Service, different kinds of habitats. The nature of this 500 NE Multnomah Street, Portland, Oregon paper and the scale of our maps do not allow 97232. for detailed resolution of each colony's loca-

21 22 J. C. BARTONEK AND S. G. SEALY

tion (for the most part this information is not Chukchi Sea Coast available), but rather facilitates a general impression of status. A disproportionate percentage of ornitho- Most place-names used by us are shown in logical investigations in arctic Alaska have Fig. 1; the others may be located by referring centered about Barrow, where ornithologists to Orth's (1967) gazetteer on Alaska. were attracted because of the propensity of vagrant birds to collect there and because of Information Base the above average facilities, conveniences, and transportation afforded first by the whal- There is no adequate catalog of marine bird ing station, then by the military, and later by colonies and other avian habitats for the a research laboratory. Recent petroleum de- Bering-Chukchi region or for Alaska as a velopment near Prudhoe Bay has resulted in a whole. King and Lensink (1971) described the somewhat commensal eastward shift in orni- waterfowl populations and major lowland thological studies. habitats of the State and listed only a few of Bailey (1948), Gabrielson and Lincoln the many colonies of cliff-nesting birds. (1959), and Pitelka (1974) reviewed much of LeResche and Hinman (1973) identified a few the published information on arctic avifauna, additional colonies, provided fragmentary in- including that of the Chukchi coast. Selkregg formation on composition and abundance at [1975] mapped various avian habitats, some of these sites, and delineated areas of ascribed either relative or absolute values for wetland habitats on maps in their statewide the population size of certain groups of birds, atlas on wildlife. General and occasionally and included a selected bibUography that did site-specific information on the location, but not entirely duplicate those provided by the rarely on population size and composition, of other reviewers. Watson and Divoky (1975) colonies can be gleaned from the 321 species described the avifauna of Alaska's Beaufort accounts presented by Gabrielson and Lin- Sea coast, which is much the same as that of coln (1959) and from the general works by the Chukchi coast from Point Barrow south to Bent (1919, 1921, 1922, 1923, 1925, 1927, Cape Lisburne (both coasts are of low reUef). 1929), Dement 'ev and Gladkov (1951), Intensive studies near Barrow have done Dement'ev et al. (1951, 1952), Pahner (1962), much to characterize the behavior, produc- Fisher (1952), Tuck (1960), and others. The tivity, and ecological requirements of calidri- birds on the Asiatic side of these waters, dine sandpipers (Pitelka 1959; Pitelka et al. which are not treated in this paper, were de- 1974; Hobnes 1970, 1971) and, to partly ex- scribed by Portenko (1973). plain the cyclical relationships between Information on the status of waterfowl in jaegers {Stercorarius spp.) and their prey (e.g., the region is generally more detailed than that Pitelka et al. 1955; Maher 1974). Quantitative for most other groups of birds because water- estimates of certain bird populations at Cape fowl have been the object of systematic sur- Thompson (Swartz 1966; WilUamson et al. veys since the late 1940's as part of the conti- 1966), Little Diomede (Kenyon and Brooks nent-wide effort to manage populations for 1960), and on the coastal lowlands of the sport hunting. Because the emphasis of these Seward Peninsula (King and Lensink 1971; surveys has been directed toward the species U.S. NPS 1973), and for black guillemots of ducks important to hunters in the "lower (Cepphus grylle) throughout the region 48" States, data are not adequate to measure (Divoky et al. 1974) are among the best data changes in populations for most sea ducks on status of marine birds for any locaUty in and marine geese nesting in this region. These Alaska. Grinnell (1900a) described the birds surveys have, however, enabled biologists to he observed in the Kotzebue Sound area. delineate waterfowl habitats and make rea- Cursory aerial surveys conducted by J. C. sonable estimates of populations for some of Bartonek, J. G. King, and D. R. Cline (U.S. the more abundant and conspicuous species FWS 1973a; U.S. NPS 1973; this paper) in (King and Lensink 1971; U.S. Fish and Wild- 1972 and 1973 provided information on the

life service [FWS] 1973c; U.S. National Park location and relative size of most, if not all, Service [NPS] 1973). colonies of cliff-nesting marine birds between ^

MARINE BIRDS OF THE CHUKCHI AND BERING SEAS 23

PT. BARROW

SEAHORSE I.

'«"''*^^^ BLUFF L. DIOMEDE^,!*.

FAIRWAY ROCK^ ^^u-x^ .-,.-. _

C. DECEIT KAGHKUSALIK KING I '%^ NW CAPE ~* 1 STOBLI RKS ROCKY PT. - ^ (^>X^w.- V- SLEDGE I r ^^"-V^^-Jt^^l "^^^^^ SW CAPE r ^'^-SINGIKPO C. „.,s,... ^C. DENBIGHr^\— somv Mbesboro i.

^ HALL I.

PINNACLE I.^^^ S^- MATTHEW I.

0& <# C. MOHICAN

ST. PAUL I.

4- .^WALRUS I.

OTTER I. ^ ST. GEORGE I

oc^^

Fig. 1. Place-names in the region of the Chukchi and Bering seas. 24 J. C. BARTONEK AND S. G. SEALY

Point Barrow and the Bering Strait, including Eskimos. Grinnell (19006) at Nome, those at Cape Lisburne, at Motherhood Point, McGregor (1902) along the Kojoik River, Nine-mile Point, Cape Deceit, Towalevic Hersey (1917) and Turner (1886) near St. Point, Sullivan Bluff, all on the northern base Michael, and Cade (1952) at Sledge Island proof the Seward Peninsula, and at Fairway vide fragmentary examples of the area's Rock. The relative size of populations of most marine bird populations. Colonies at King, species was probably underestimated because Besboro, Egg, and Sledge islands, near York the burrow- and crevice-nesting species were Mountains, and at Bluff were described in largely unseen. proposals for new National Wildlife Refuges (U.S. FWS 1973a). Bering Sea Sealy et al. (1971) reviewed the literature Aside from work by Gabrielson and Lincoln and discussed the various zoogeographic relationships the avifauna of St. (1959) and the early but understandably in- among Lawrence Island. complete accounts by Nelson (1883, 1887) and Fay and Cade (1959) estimated numbers and of all birds St. Turner (1886), no comprehensive description biomass on Lawrence of the avifauna of the Alaskan coast of the Island but did not identify locations and sizes of particular populations; consequently, repli- Bering Sea exists. Many studies adequately describe local avifauna, and some of them are cation of their estimates is precluded. An exemplary assessments of the status of exemplary study by Bedard (1969) identified populations. the locations and sizes of all populations of Most of the coastUne suitable for cUff-nest- crested auklets {Aethia cristatella), least auk- ing marine birds and most of the smaller near- lets (A. pusilla), and parakeet auklets (Cyclor- shore islands from the Bering Strait south to rhynchus psittacula) on the island. Sealy the tip of the Alaska Peninsula were recon- (1973) identified breeding sites of horned noitered piecemeal from aircraft between 1970 puffins (Fratercula comiculata) there and and 1973 by J. C. Bartonek, J. G. King, D. R. throughout the species' range. Thompson Cline, C. D. Evans, and M. L. Plenert (U.S. (1967) listed the birds observed at Northeast FWS 1973a, 19736; this paper). In late June Cape and on nearby Punuk Islands. 1973 Bartonek, CUne, and Plenert made brief Annotated accounts have been pubUshed on reconnaissances on foot of King, Besboro, and the breeding avifauna of St. Matthew, Hall, Pinnacle islands Shaiak islands. Bartonek and J. G. Divoky, and by Elliott (1882), Hanna traveUng by boat and occasionally on foot, re- (1917), Bent (19l9), and Gabrielson and connoitered colonies at Cape Seniavin, a por- Lincoln (1959). Klein (1959) presented quanti- tion of the Walrus Islands group, Shaiak tative data on the birds he observed inci- Island, and the coasthne from Cape Peirce dental to his study of reindeer {Rangifer around Cape Newenham to Security Cove tarandus). (U.S. FWS 1973a, 19736; this paper). Al- The avifauna of the Yukon-Kuskokwim though these cursory surveys (especially delta, which is rich both in numbers and diver- those from aircraft) tended to identify nesting sity, has been treated extensively in the litera- sites of cliff-nesting birds while missing sites ture. Nelson (1883, 1887), Turner (1886), Con- used by burrow- and crevice-nesting species, over (1926), Brandt (1943), Gabrielson and information was obtained on the location and Lincoln (1959), WiUiamson (1957), Kessel et relative size of many previously unreported al. (1964), Harris (1966), Dau (1972), and colonies. Holmes and Black (1973) all described the avi- The mainland and island colonies in Norton fauna in the same general area of the delta,

Sound have received little notice in the pub- i.e., the eroding portion in the general vi- lished Uterature. Bailey (1943, 1948), although cinity of Hooper and Hazen bays. The avi- working mainly at Little Diomede and in Arc- fauna of the aggrading portion of the Yukon tic and Lopp lagoons on the north side of the delta and of the Kuskokwim's mouth have not Seward Peninsula, mentioned the birds at been accorded similar attention. Populations Wales Mountain and Tin City. Nelson (1883, of waterfowl nesting on the delta and their 1887) traveled throughout the region study- wintering affinities were described by King ing the avifauna and the anthropology of and Lensink (1971) and U.S. FWS (1973c). MARINE BIRDS OF THE CHUKCHI AND BERING SEAS 25

Studies of particular species of marine birds Lincoln (1959) summarized the few observa- on the delta (again, all in the general vicinity tions by Osgood (1904) and Turner (1886) in of Hooper and Hazen bays) were reported by this area, but obviously were unaware that, in Hansen and Nelson (1957) and Shepherd aggregate, these colonies rival those of the (1960) for black brant (Branta bernicla), by Pribilofs. Dick and Dick (1971) made an Headley (1967) and Eisenhauer and Kirk- exemplary study of marine birds and their patrick (1977) for emperor geese (Anser cana- numbers at Cape Peirce and on nearby Shaiak gica), by Dau (1974) and Mickelson (1975) for Island. Murie (1959) provided annotated re- spectacled eiders (Somateria fischeri), by marks on marine birds of Amak Island, but Petersen (1976) for red-throated loons (Gauia not of nearby Sealion Rocks. stellata), and by Holmes (1970, 1971, 1972) for dunlins (Calidris alpina) and western sandpipers (C mauri). Status and Distribution Birds of Nunivak Island were reported by Seven groups of colonies of cliff-, burrow-, Swarth (1934), but the importance of the and crevice-nesting birds are found on the island to marine birds was not put into proper headlands and islands in the coastal region, perspective until the Nunivak National Wild- each numbering more than 1 million birds; life Refuge was evaluated for designation as a nine colonies range downward to 100,000 wilderness area (U.S. 1972). FWS birds; and a host of others range downward to The Pribilof Islands have served as a focal 1,000 birds (Fig. 2). Unestimated numbers of point for ornithological investigations of the other marine birds nest on the lowlands about Bering Sea in much the same that Bar- way Kotzebue Sound, the Yukon-Kuskokwim row has for the Arctic. The avifauna of the delta, and Bristol Bay, but are not shown in Pribilofs has been described by Coues (1874), Fig. 2. The occurrence at colonies of 20 of the Elliott (1882), Palmer (1899), Hanna (1918), Preble and McAtee (1923), Gabrielson and Lincoln (1959), Kenyon and Phillips (1965), and a host of others that mainly added new species to the record list. Although most of these ornithologists marveled at the numbers of birds, information is lacking from which most changes in populations can be noted. (An exception is the record of common and thick-billed murres, Uria aalge and U. lomvia, which formerly nested in such abundance on Walrus Island that annually several tons of eggs were gathered for consumption by residents of the islands [Palmer 1899], but were greatly reduced in numbers by the summM- of 1973, when J. C. Bartonek, J. G. King, G. J. Divoky, and D. T. Montgomery observed only a few thousand murres on a small portion of the island. Most of the suitable nesting sites, especially the flat areas often used by common murres, were occupied by Steller's sea lions, Eumetopias jubata, which, apparently because of reduced hunting pressure, occupied the island and displaced the murres.) For some unexplained reason the numerous and large marine bird colonies along the north side of Bristol Bay appear to have been Fig. 2. Relative numbers of marine birds at colonies largely overlooked until recent years (Bar- in different localities, without regard to species tonek and Gibson 1972). Gabrielson and composition or breeding status. J. C. BARTONEK AND S. G. SEALY

NORTHERN FULMAR^ DOUBLE-CRESTED PELAGIC RED-FACED CORMORANT CORMORANT CORMORANT

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BLACK BRANT EMPEROR GOOSE GLAUCOUS GLAUCOUS-WINGED ^ d CULL GULL -^^^

(^ 9

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•4;:^;^^ --.^..-^-. -z^m. ,^^ ^^'^• j^

Fig. 3. Location of known breeding populations of some marine bird species without regard to size of population. MARINE BIRDS OF THE CHUKCHI AND BERING SEAS 27

BLACK GUILLEMOT ^* PIGEON GUILLEMOT, q KITTLITZ'S „ . PARAKEET AUKLET ^ q MURRELET .^-^^

OJ^-^r ^fls. __i^^- .i^-- r^J:)^ .'^^

CRESTED AUKLET LEAST AUKLET HORNED PUFFIN TUFTED PUFFIN

c-s-rw%-^As. J^ ^^^••

nearly 100 species of marine birds is shown in puffins, tufted puffins {Lunda cirrhata), Fig. 3; their relative numbers at these sites pelagic cormorants (Phalacrocorax pelagicus), are not shown because data are generally and glaucous gulls (Larus hyperboreus) make lacking. up the remaining majority. For the whole area there are probably fewer than a hundred birds each of black guillemots and pigeon guille- Chukchi Sea mots (Cepphus columba) occupying colonies. The largest colonies of seabirds in the Chuk- Dovekies (AHe alle) are occasionally sighted in chi Sea are those on Little Diomede Island, this area, but only as stragglers from their Cape Lisburne, Cape Thompson, and Fairway normal range. Rock. Smaller colonies are in Kotzebue Sound Part of the mystery surrounding the nest- along the northern base of the Seward Penin- ing location of Kittlitz's murrelet (Brachy- sula. These colonies are largely dominated by ramphus brevirostris) was solved when thick-billed and common murres and black- Thompson et al. (1966) discovered a downy legged kittiwakes {Rissa tridactyla) and on chick in the Kukpuk River drainage nearly the islands in the Bering Strait also the 45 km by river from salt water. Other nesting crested, least, and parakeet auklets. Horned sites of the Kittlitz's murrelets in this region 28 J. C. BARTOKEK AND S. G. SEALY

were reported for Wales Mountain (Ford kittiwakes {Rissa brevirostris). They are also 1936; Bailey 1943, 1948) and the Cold Bay interesting from the zoogeographic stand- area (Bailey 1973) (Fig. 3). point in that they are the northernmost Only the colonies at Cape Thompson have stronghold of red-faced cormorants {Phalacro- been censused systematically throughout a corax urile); guillemots are conspicuous by breeding season. During one of three years of their absence, and larid gulls are con- varying census efforts, Swartz (1966) esti- spicuously scarce nesters. mated that about 400,000 birds of nine St. Matthew Island and associated Hall and species occupied the cliffs. Whereas the Cape Pinnacle islands, and all but Walrus Island of Thompson colonies received considerable at- the Pribilofs, are sites of nesting northern ful- tention because of Swartz's efforts, the colo- mars (Fulmarus glacialis). Nesting fork-tailed nies that extend along nearly 35 km of head- or Leach's storm-petrels (Oceanodroma fur- lands southward from, but mainly at. Cape cata and O. leucorhoa) have been found no- Lisburne have received little if any attention where in this region, although both are com- by either early or recent ornithologists in the monly observed at sea and both nest through- Arctic, even though they support perhaps out the Aleutians. twice the number of birds. Also perplexing is Most colony sites identified in Fig. 2 are why Chamisso and Puffin islands with their dominated by common or thick-billed murres several thousand nesting horned puffins and (or both) and black-legged kittiwakes. Glau- lesser numbers of other seabirds were desig- cous gulls (generally north of the Yukon- nated as the Chamisso National WildUfe Kuskokwim delta), glaucous-winged gulls Refuge in the early 1900's when none of the {Larus glaucescens) (generally to the south of many larger and more species-diverse colonies the delta), and pelagic cormorants occupy al- in the area received comparable recognition most every rocky prominence along the entire by and protection through refuge designation. coast (most of these sites are not shown in The lowlands on the north side of the Figs. 2 and 3). Double-crested cormorants Seward Peninsula produce fall flights of sea (Phalacrocorax auritus) nest at a few island ducks that average 49,200 oldsquaws (Clan- and inland locations in the Bristol Bay area. gula hyemalis), 51,000 eiders (mostly common The small auklets are largely restricted to eiders, Somateria mollissima), and 26,700 islands in the Bering Sea; the parakeet auklet scoters (mostly black scoters, Melanitta is the only one occasionally found in mainland nigra) (King and Lensink 1971). Small popula- colonies. tions of black brant and emperor geese breed The marine birds of the Yukon-Kuskokwim in what outwardly appears to be excellent delta lowlands, although largely uncounted, habitat, and King and Lensink (1971) specu- in their aggregate probably exceed the num- lated that subsistence hunting by local bers at any individual site identified in Fig. 2. Eskimos is responsible for suppressing these This is not particularly surprising since the populations. delta has nearly 70,000 km^ of habitat (King and Lensink 1971) in contrast to the generally Bering Sea small parcels of habitat occupied at the sea- The largest concentration of nesting sea- cliff and island sites. birds in the Bering Sea and perhaps in the en- King and Lensink (1971) estimated that fall tire North Pacific is that on St. George flights of sea ducks originating on the delta Island. Colonies that rank somewhere below averaged 292,300 oldsquaws, 51,000 eiders that at St. George are along the coast from (mostly common and spectacled eiders with Cape Newenham to Cape Peirce, in the Walrus lesser numbers of Steller's eiders, Polysticta Islands (Round, High, Crooked, and Summit stelleri), and 157,000 scoters (primarily black islands. The Twins, and Black Rock), at Cape scoters). They also estimated that half of the Mohican on Nunivak Island, St. Matthew 150,000 black brant and most of the 150,000 Island, Southwest Cape of St. Lawrence emperor geese in Alaska's fall flight originate Island, and King Island. there. Although no counts have been made, The Pribilofs have the unique distinction of we believe that the delta's lowlands support being the primary nesting site of red-legged easily more than half of Alaska's nesting dun- MARINE BIRDS OF THE CHUKCHI AND BERING SEAS 29

lins, black turnstones (Arenaria melano- less than 10 years. We therefore recommend cephala), rock sandpipers (Calidris ptiloc- that long-term studies be initiated at as many nemis), western sandpipers, and substantial places as possible, but at least at one site on percentages of red phalaropes (Phalaropus the Yukon-Kuskokwim delta; at a mainland fulicarius), northern phalaropes {Lobipes colony site that has predominantly murres, lobatus), and red-throated loons. kittiwakes, puffins, and cormorants; and at The north side of the Alaska Peninsula (in- an island site that also has small auklets. Al- cluding the wetlands, uplands, and estuaries) though the nesting distribution of the Kitt- is perhaps more important to marine birds as litz's murrelet remains an enigma, we regard a staging, feeding, and resting area than as a it less of a conservation issue and more of an nesting habitat. The importance of Izembek ornithological challenge. Consideration of Lagoon to black brant and emperor geese dur- logistics and support facilities must, of ing fall and spring is a classic example. King course, be included in the site selection pro- and Lensink (1971) estimated that the fall cess. Most of the areas suggested for these flight of sea ducks originating from the Penin- studies also merit recognition and protection sula averages 53,400 oldsquaws, 1,700 eiders, by being designated as a National Wildlife and 74,400 scoters. Breeding geese are scarce Refuge, a National Park or Monument, or a throughout the area. State Game Sanctuary,

Conclusions and References Recommendations Bailey, A. M. 1943. The birds of Cape Prince of Most of the major breeding habitats of Wales, Alaska. Proc. Colo. Mus. Nat. Hist. 18. marine birds in the Chukchi and Bering seas 113 pp. are known, but imprecisely identified as to Bailey, A. M. 1948. Birds of arctic Alaska. Colo. location and size. With few exceptions, the Mus. Nat. Hist. Popular Ser. 8. 317 pp. Bailey, E. P. 1973. Discovery of a Kittlitz's murre- populations of birds using these habitats are let nest. Condor 75(4):457. described only the subjective by and am- Bartonek, J. C, and D. D Gibson. 1972. Summer biguous descriptors of abundance such as distribution of pelagic birds in Bristol Bay, "abundant, common, occasional, and rare," Alaska. Condor 74(4):416-422. Bedard, J. 1969. The nesting of the least, crested, which makes measurement of change im- and parakeet auklets around St. Lawrence possible. Island, Alaska. Can. J. Zool. 47(5): 1025-1050. We recommend that first and foremost a Bent, A. C. 1919. Life histories of North American catalog of habitats used by birds be developed diving birds. U. S. Natl. Mus. Bull. 107. 245 pp. to aid resource administrators, developers, Bent, A. C. 1921. Life histories of North American gulls and terns. U.S. Natl. Mus. Bull. 113. and biologists (all of whom should be "conser- 345 pp. vationists") in identifying critical habitats. Bent, A. C. 1922. Life histories of North American We believe that such a catalog would preclude petrels, pelicans, and their allies. U. S. Natl. Mus. many problems because birds and their habi- Bull. 121.343 pp. tats could be considered at the planning stage Bent, A. C. 1923. Life histories of North American wild fowl. Part I. U. S. Natl. Mus. Bull. 126. rather than only at the operational stage. 250 pp. Such a catalog would also be useful to stu- Bent, A. C. 1925. Life histories of North American dents of ornithology who are seeking loca- wild fowl. Part H. U. S. Natl. Mus. Bull. 130. tions suitable for particular studies. 311pp. Bent, A. C. 1927. Life histories of North American Nowhere in this region have studies of shore birds. Part L U. S. Natl. Mus. Bull. 142. marine birds been of sufficient duration to en- 359 pp. able changes in populations (from whatever Bent, A. C. 1929. Life histories of North American cause) to be characterized. Since some species shore birds. Part H. U. S. Natl. Mus. BuU. 146. of marine bird are known not to breed before 340 pp. Brandt, H. 1943. Alaska bird trails. Bird Research at least 3 or more years of age, meaningful in- Foundation, Cleveland, Ohio. 464 pp. formation on survival and recruitment in Cade, T. J. 1952. Note on the birds of Sledge Island, populations cannot be obtained by studies of Bering Sea, Alaska. Condor 52(l):51-54. 30 J. C. BARTONEK AND S. G. SEALY

Conover, H. B. 1926. Game birds of the Hooper Bay Hansen, H. A., and U. C. Nelson. 1957. Brant of the region, Alaska. Auk 43(2):162-180, 43(3):308-318. Bering Sea—migration and mortality. Trans. N. Coues, E. 1874. Ornithology of the Prybilov Am. WUdl. Nat. Resour. Conf. 22:237-256. Islands. Pages 168-212 in H. W. Elliott, Report Harris, S. W. 1966. Summer birds of the lower on the Prybilov Group, or Seal Islands of Alaska. Kashunuk River, Yukon-Kuskokwim delta, U. S. Treasury Department, Washington, D. C. Alaska. Murrelet 47(3):57-65. Dau, C. 1972. Observations on the spring migration Headley, P. C. 1967. Waterfowl. Ecology of the of birds at Old Kashunuk Village, Alaska. Univ. emperor goose. Alaska Dep. Fish Game Small Alaska, Dep. Wildl. Fish., Fairbanks. 54 pp. (Un- Furbearer Invest. 8:1-25. published report) Hersey, F. S. 1917. The present abundance of birds Dau, C. 1974. Nesting biology of the spectacled in the vicinity of Fort St. Michael, Alaska. Auk eider Somateria fischeri (Brandt) on the Yukon- 34(2):147-159. Kuskokwim delta, Alaska. M. S. Thesis. Univ. of Holmes, R. T. 1970. Differences in population den- Alaska, Fairbanks. 72 pp. sity, territoriality, and food supply of dunlin on Dement'ev, G. P., and N. A. Gladkov. 1951. Birds of arctic and subarctic tundra. Pages 303-319 in A. the Soviet Union. Vol. 1. (Transl. from Russian.) Watson, ed., Animal populations in relation to Israel Progr. Sci. Transl., 1966. 705 pp. their food resources. Br. Ecol. Soc. Symp. 10. Dement'ev, G. P., N. A. Gladkov, Yu. A. Isakov, Holmes, R. T. 1971. Density habitat and mating N. N. Kartashev, S. V. Kirikov, A. V. Mikheev, system of the western sandpiper (Calidris mauri). and E. S. Ptushenko. 1952. Birds of the Soviet Oecologia7(2):191-208. Union. Vol. 4. (Transl. from Russian.) Israel Holmes, R. T. 1972. Ecological factors influencing Progr. Sci. Transl., 1967. 683 pp. the breeding season schedule of western sand- Dement'ev, G. P., N. A. Gladkov, and E. P. pipers (Calidris mauri) in sub-arctic Alaska. Am. Spageburg. 1951. Birds of the Soviet Union. Vol. Midi. Nat. 87(2):472-491. 2. (Transl. from Russian.) Israel Progr. Sci. Hohnes, R. T., and C. P. Black. 1973. Ecological dis- Transl, 1968. 553 pp. tribution of birds in the Kolomak River-Askinuk Dick, M. H., and L. S. Dick. 1971. The natural his- Mountain region, Yukon-Kuskokwim delta, tory of Cape Peirce and Nanvak Bay, Cape Alaska. Condor 75(2):150-163. Nat'l. Wildl. Refuge, Alaska. U. S. Newenham KeUey, E. J., and D. W. Hood, eds. 1974. PROBES: Bureau Sport Fisheries and Wildlife, Bethel, a prospectus on processes and resources of the Alaska. 78 pp. Bering Sea shelf, 1975-1985. Univ. Alaska, Inst. Divoky, G. J., G. E. Watson, and J. C. Bartonek. Mar. Sci. Publ. Inf. Bull. 75-1. 71 pp. 1974. Breeding of the black guillemot in northern Kenyon, K. W., and J. W. Brooks. 1960. Birds of Alaska. Condor 76(3):339-343. Little Diomede Island, Alaska. Condor 62(6):457-

Eisenhauer, D. I., and C. M. Kirkpatrick. 1977. 463. Ecology of the emperor goose in Alaska. Wildl. Kenyon, K. W., and R. E. Phillips. 1965. Birds from Monogr. 57. 62 pp. the Pribilof Islands and vicinity. Auk 82(4):624- EUiott, H. W. 1882. Seal-islands of Alaska. U. S. 635. Comm. Fish Fish. Spec. BuU. 176, Sect. IX, Kessel, B., H. K. Springer, and C. M. White. 1964. Monogr. A. 176 pp. June birds of the Kolomak River, Yukon-Kusko- Fay, F. H., and T. J. Cade. 1959. An ecological kwim delta, Alaska. Murrelet 45(3):37-47. analysis of the avifauna of St. Lawrence Island, King, J. G., and C. J. Lensink. 1971. An evaluation Alaska. Univ. CaUf. Publ. Zool. 63:73-150. of Alaskan habitat for migratory birds. U. S. Bur. Fisher, J. 1952. The fulmar. N.M.N. Collins, Sport Fish. Wildl., Washington, D. C. 46 pp. (Un- London. 496 pp. pubUshed administrative report) Ford, E. R. 1936. Kittlitz's murrelet breeding at Wales, Alaska. Auk 51:214-215. Klein, D. R. 1959. Saint Matthew Island reindeer- Wildl. Serv., Sci. Gabrielson, I. N., and F. C. Lincoln. 1959. The birds range study. U. S. Fish Spec. of Alaska. The Stackpole Co., Harrisburg, Penn- Rep. -Wildl. 43. 48 pp. sylvania, and WildUfe Management Institute of LeResche, R. E., and R. A. Hinman, eds. 1973. North America, Washington, D. C. 992 pp. Alaska's wildlife and habitat. Alaska Depart- Grinnell, J. 1900a. Birds of the Kotzebue Sound re- ment of Fish Game, Juneau. 144 pp. + 564 maps. gion, Alaska. Pac. Coast Avifauna 1. 80 pp. Maher, W. J. 1974. Ecology of pomarine, parasitic, Grinnell, J. 19006. Notes on some birds of Cape and long-tailed jaegers in northern Alaska. Pac. Nome, Alaska. Condor 2(5):112-115. Coast Avivauna 37. 148 pp. Hanna, G. D. 1917. The summer birds of the St. McGregor, R. C. 1902. A list of birds collected in Matthew Island Bird Reservation. Auk 34(4):403- Norton Sound, Alaska. Condor 4(6):135-144. 410. Mickelson, P. G. 1975. Breeding biology of cackling Hanna, G. D. 1918. Check list of birds of the Pribi- geese and associated species on the Yukon- lof Islands, Alaska, with names of persons first Kuskokwim delta, Alaska. Wildl. Monogr. 45. recording the species from the islands. Pages 105- 35 pp. 107 in W. T. Bower, ed.. Report of U. S. Commis- Murie, O. J. 1959. Fauna of the Aleutian Islands sioner of Fisheries. Bureau of Fisheries Docu- and Alaska Peninsula. U. S. Fish WUdl. Serv., N. ment 872. Am. Fauna 61:1-364. MARINE BIRDS OF THE CHUKCHI AND BERING SEAS 31

Nelson, E. W. 1883. Birds of the Bering Sea and Data Cent., Anchorage. 218 pp. Arctic Ocean. Pages 44-120 in Cruise of the Reve- Shepherd, P. E. K. 1960. Production and abundance nue-steamer Corwin in Alaska and the N. W. Arc- of the black brant in Alaska. Alaska Dep. Fish tic Ocean. U. S. Treas. Dep. Doc. 429. Game, Game Div. Pittman-Robertson Proj. Rep. Nelson, E. W. 1887. Report on natural history col- 2(8):58-77. lections made in Alaska between the years 1877 Swarth, H. S. 1934. Birds on Nunivak Island, and 1881. U.S. Army, Signal Serv. Arct. Ser. Alaska. Pac. Coast Avifauna 22. 64 pp. Publ. 3. 337 pp. Swartz, L. G. 1966. Sea-cliff birds. Pages 611-678 in Orth, D. J. 1967. Dictionary of Alaska place names. N. J. Wilimovsky and J. N. Wolfe, eds. Environ- U. S. Geol. Surv. Prof. Pap. 567. 1084 pp. ment of the Cape Thompson region, Alaska. U. S. Osgood, W. H. 1904. A biological reconnaissance of AEC, Div. Tech. Inf., Oak Ridge, Tennessee. the base of the Alaska Peninsula. U. S. Dep. Thompson, C. F. 1967. Notes on the birds of the Agric, Div. Biol. Surv., N. Am. Fauna 24:9-86. Northeast Cape of St. Lawrence Island and of the Pahner, R. S., ed. 1962. Handbook of North Ameri- Punuk Islands, Alaska. Condor 69(4):41 1-419. can birds. Vol. 1. Loons through flamingos. Yale Thompson, M. C, J. Q. Hines, and F. S. L. WilUam- Univ. Press, New Haven, Conn. 567 pp. son. 1966. Discovery of the downy young of Kitt- Pahner, W. 1899. The avifauna of the Pribilof Utz's murrelet. Auk 83(3):349-351. Islands. Pages 355-431 in D. S. Jordan, ed. The Tuck, L. 1960. The murres. Can. Wildl. Serv. Ser. 1. fur seals and Fur Seal Islands of the North 260 pp. Pacific, Part III. U. S. Treasury Department, Turner, L. M. 1886. Contributions to the natural Commercial Fur-seal Investigations, Washing- history of Alaska. U. S. Army, Signal Serv. Arct. ton, D. C. Ser. Publ. 2. 226 pp. Petersen, M. R. 1976. Breeding biology of arctic U. S. Fish and Wildlife Service. 1972. Nunivak Na- and red-throated loons. M. S. Thesis. Univ. of tional Wildlife Refuge wilderness study report. CaUfornia, Davis. 55 pp. Agency, Anchorage, Alaska. 200 pp. Pitelka, F. A. 1959. Numbers, breeding schedules, U. S. Fish and WildUfe Service, Alaska Planning and territoriality in pectoral sandpipers of north- Group. 1973a. Proposed Alaska Coastal Refuges, ern Alaska. Condor 61(4):233-264. Alaska. Agency Draft Environ. Statement 73-94. Pitelka, F. A. 1974. An avifaunal review for the Bar- 247 pp. + appendixes. row region and North Slope of Alaska. Arct. Alp. U. S. Fish and Wildlife Service, Alaska Planning Res.6(2):161-184. Group. 19736. Proposed Togiak National WildUfe Pitelka, F. A., R. T. Holmes, and S. F. MacLean, Jr. Refuge. Agency Draft Environ. Statement 73- 1974. Ecology and evolution of social organiza- 100. 183 pp. + appendixes. tion in arctic sandpipers. Am. Zool. 14:185-204. U. S. Fish and Wildlife Service, Alaska Planning Pitelka, F. A., P. Q. Tomich, and G. W. Treichel. Group. 1973c. Proposed Yukon Delta National 1955. Ecological relations of jaegers and owls Wildhfe Refuge, Alaska. Agency Draft Environ. near Barrow, Alaska. Condor 57(1): 3-18. Statement 73-101. 205 pp. + appendixes. Portenko, L. A. 1973. The birds of the Chukotsk U. S. National Park Service, Alaska Planning Peninsula and Wrangel Island. Acad. Sci. Group. 1973. Proposed Chukchi-Imuruk National S.S.S.R., Zool. Inst., Sci. Publishers, Leningrad. 2 Wildlands, Alaska. Agency Draft Environ. State- vols. [In Russian.] ment 73-84. 306 pp. + appendixes. Preble, E. A., and W. L. McAtee. 1923. A biological Watson, G. E., and G. J. Divoky. 1975. Marine survey of the Pribilof Islands, Alaska. Part I. birds in the Beaufort Sea. Pages 681-695 in J. C. Birds and mammals. U. S. Bur. Biol. Surv., N. Reed and J. E. Sater, eds. The coast and shelf of Am. Fauna 46:1-128. the Beaufort Sea. Arctic Institute of North Sealy, S. G. 1973. Breeding biology of the horned America, Washington, D. C. puffin on St. Lawrence Island, Bering Sea, «vith Williamson, F. S. L. 1957. Ecological distribution of zoogeographical notes on the North Pacific birds in the Napaskiak area of the Kuskokwim puffins. Pac. Sci. 27:99-119. River delta, Alaska. Condor 59(5):3 17-338. Sealy, S. G., F. H. Fay, J. Bedard, and M. D. F. Williamson, F. S. L., M. C. Thompson, and J. Q. Udvardy. 1971. New records and zoogeographical Hines. 1966. Avifaunal investigations. Pages notes on the birds of St. Lawrence Island, Bering 437-480 in N. J. Wilimovsky and J. N. Wolfe, eds. Sea. Condor 73(3):322-336. Environment of the Cape Thompson region, Selkregg, L. L., ed. [1975]. Alaska regional profiles: Alaska. U. S. AEC, Div. Tech. Inf., Oak Ridge, Arctic regfion. Univ. Alaska, Arct. Environ. Inf. Tennessee. 1250 pp.

Breeding Distribution and Status of Marine Birds in the Aleutian Islands, Alaska

Palmer C. Sekora*

U. S. Fish and Wildlife Service Kailua, Hawaii

G. Vernon Byrd^

U. S. Fish and Wildlife Service Adak, Alaska

and

Daniel D. Gibson

University of Alaska Fairbanks, Alaska

Abstract

Seabird population estimates are generally lacking for the 1,800-km-long Aleutian Islands. Only the locations of the larger colonies are known, and for these there are only imprecise estimates of colony sizes and often even of species composition. Changes in the status of several species and populations resulting from geologic and marine actions and from human intrusions are evident. Ac- counts are given for 25 species of marine birds breeding in these islands.

The 1,800-km-long chain of islands known available to place colonies in broad size as the Aleutians provides nesting habitat for ranges. PubUshed information on the breed- various species of marine birds, including ing biology of marine birds is also lacking three species of Pi ocellariiformes and three of from the Aleutians, but some studies are cormorants (Phalacrocorax spp.), one species under way. The distribution of nesting marine of gull {Larus glaucescens), both kittiwake birds away from the nesting cliffs is totally species {Rissa spp.), two species of terns unknown. (Sterna spp.), and at least 13 species of alcids. Introduced predators, primarily arctic Seabird population estimates of known ac- foxes (Alopex lagopus), are now found on curacy are lacking for this isolated area. Loca- nearly every island. Breeding marine bird tions of larger colonies of breeding seabirds populations have suffered drastic reductions are known, however, and sufficient data are as a result. They have probably also changed because of natural habitat modifications caused by earthquakes, volcanic eruptions, 'Present address: U. S. Fish and Wildlife Service, tidal waves, marine erosion. William L. Finley National Wildlife Refuge, Route and this is to summarize 2, Box 208, Corvallis, Oregon 97330. The purpose of paper 'Present address: U. S. Fish and Wildlife Service, the known present distribution and status of Kilauea, Hawaii. breeding marine birds in the Aleutian Islands.

33 34 P. C. SEKORA, G. V. BYRD, AND D. D. GIBSON

Description of the lion {Eumetopias jubata) are scattered Aleutians during summer, Aleutian Islands throughout the and numerous harbor seals (Phoca vitulina) haul out on beaches and offshore rocks. The Aleutian Islands form an arc that sepa- All five species of Pacific salmon {Oncorhyn- rates the Bering Sea and the north Pacific chus spp.) occur near the islands, and at least Ocean (Fig. 1). The island chain extends from four of them (all but O. tshawytscha) spawn in the tip of the Alaska Peninsula to within Aleutian streams. Dolly Varden (Salvelinus 483 km of the Commander Islands of Siberia. malma) and threespine sticklebacks (Gas- The chain contains more than 200 islands— terosteus aculeatus) are found nearly every- the peaks of a submarine volcanic mountain where there is fresh water. The marine envi- range. Volcanic activity and earthquakes oc- ronment provides habitat used by at least 77 cur regularly. species of fish (Isakson et al. 1971). O 'Clair Weather is characterized by perpetual over- and Chew (1971) furnished a recent reference cast, dense summer fog, high-velocity winds, to littoral macrofauna at Amchitka. and mild temperatures with low annual and About 200 species of birds have been re- diurnal variations. The sea is ice-free year- corded in the Aleutians (Aleutian Islands Na- round except in extremely cold winters, when tional Wildlife Refuge, unpublished data). the arctic ice pack may reach the extreme Many of these are windblown stragglers from northern islands. both North America and Asia; only 59 species are treeless except for a few The Aleutians breed on the islands. Although seabirds make introduced, stunted spruces. Woody shrubs up less than half (26 species or 44%) of the to the most northern islands on are restricted breeding birds, they may compose more than of the Chain, Mosses, lichens, club each end 90% of the breeding avian biomass. mosses, and heaths are common ground-cover plants, and taller grasses, sedges, and umbel- lifers constitute the overstory. Hulten (1960) provided a list of terrestrial plants found in Ornithological Investigations Aleutians. Amundsen and Clebsch (1971) the in the Aleutians discussed terrestrial plant ecology at Am- central Aleutians. The marine plant chitka, Published ornithological information from communities around the islands are fairly di- the Aleutian Islands is relatively scarce. verse. Lebednik et al. (1971) described marine G. W. Steller, naturalist on Vitus Bering's algal communities at Amchitka. 1741 expedition to Alaska, was the first per- The easternmost Aleutian island, Unimak, son to record ornithological information in the has a mammalian fauna like that of the islands (Stejneger 1936). More than a century Alaska Peninsula, including brown bear passed before W. H. Dall (1873, 1874) pub- {Ursus arctos), caribou {Rangifer tarandus), lished the next papers dealing with birds in wolf {Canis lupus), and wolverine (Gulo gulo). the Aleutians. In 1878, the U. S. Army Signal West of Unimak, red foxes {Vulpes fulva) oc- Corps sent L. M. Turner to the Aleutians to curred historically as far as Umnak, and arc- set up weather stations at several locations. tic foxes were apparently on Attu when the Turner kept notes on birds at various loca- Russians came in 1741 (Murie 1959). Except tions in the Aleutians and pubUshed two for man and dog, no land mammals occurred papers (1885, 1886) on his observations. between Umnak and Aggatu islands. Arctic Turner's data (1886) provided the first report foxes, introduced before 1930 for fur farming, based on extended and widespread observa- still roam almost every island. Norway rats tions in the area. E. W. Nelson, who replaced (Rattus norvegicus) were introduced on many Turner, also provided data on birds (Nelson islands when ships were wrecked or as a result 1887). of miUtary activities during World War II. In 1906, A. C. Bent came to the Aleutians Sea otters (Enhydra lutris) have repopu- specifically to look for birds, and he and lated most of the Aleutians after being nearly Alexander Wetmore recorded birds through- extirpated by 1900. Rookeries of Steller's sea out the island chain (Bent 1912). A. H. Clark MARINE BIRDS IN THE ALEUTIAN ISLANDS, ALASKA 35

ATTU I. KRCNITZIN IS. VV ALAID I. BOGOSLOF I.AKUN I. -S^.-. T I GAL DA I

', StMICHI IS. - -^j^AKUTAN I ^ SHEMYA I. I E I S t UMNAK I. BABY IS. AGATTU I. CARLISLE I UNALASKA I. SEGULA I. YUNASKA I. SEMISOPOCHNOI I ,-„, , ^ *Tiy^ .V, .• '-CHAGALUK''CHAGALUK I,I "C „uc,\HW^" *-*^ „ TflNOra I <;ITKIN T Z' i- ,s fiARELOI I. ™*'^' ' '• * ..*' *RATIS. ^'J'^'; jy' <-, C^^^^' •• ** ^^rC'^^'^KASATOCHI iT^LIA I. ,s.O»

KANAGA I. *DAK I.

Fig. 1. The Aleutian Islands.

(1910) provided a valuable record of his obser- every large island as far west as Buldir was vations in the Near Islands. All these workers visited, and seabird colonies were mapped. recorded birds in several locations, but none Every island has been visited at least once provided data on more than a very few sea- since 1972. bird colonies.

O. J. Murie, U. S. Biological Survey, made Methods the most complete survey of the Aleutians (Murie 1959). He specifically recorded seabird In estimating the current status of seabirds colonies, spending parts of four summers in in the Aleutians, all available data were con- the area. Murie visited every large Aleutian sidered. Most of the information used, how- island and most small ones. He recorded ever, is from surveys conducted by the U. S. nearly every major colony of cliff-nesting or Fish and Wildlife Service (1970-75, unpub- talus-nesting seabirds known in the Aleu- lished data). Because these surveys only inci- tians, but seldom gave sizes of colonies, and dentally included Unimak, Akun, Akutan, separate colonies on a particular island were Unalaska, and Umnak islands, data for these often not differentiated. areas are almost totally lacking. Data for World War II brought several ornitholo- Bogoslof, Adak, Amchitka, Buldir, Agattu, gists to the Aleutians. Cahn (1947), Sutton Nizki, Alaid, and Attu are most accurate be- and Wilson (1946), Taber and (1946), Wilson cause fairly intensive investigations have (1948) provided accounts of birds observed at been conducted there since 1970. specific locations. After the war. Fish and The available data are of unknown accu- Wildlife Service personnel—including I. N. racy. The method used by most investigators Gabrielson (Gabrielson and Lincoln 1959), who have surveyed areas in the Aleutians for K. W. Kenyon (Kenyon and 1961), R. D. Jones seabird colonies has been to circle islands in a (Refuge Narrative Reports 1949-1970)—re- ship or small boat; when a colony was en- corded observations of breeding seabirds at countered, they simply estimated the number several locations in the Aleutians. Investiga- of birds they saw at the time. The accuracy of tions associated with Atomic Energy Com- the estimates is affected by weather, distance mission nuclear testing at Amchitka Island from the colony, density of birds, ability and provided the first ecological study of avifauna experience of the observer, and other vari- of an Aleutian island (White et al. 1977). Byrd ables. Estimates of kittiwakes and cor- et al. provided list (1974) a of birds at Adak. morants should be the most accurate, since In 1971, the Near Islands were surveyed by nests were actually counted. Murres {Una U. S. Fish and Wildlife personnel in a Cape spp.) are readily visible on the cliffs, but the Cod dory. In 1972, the Aleutian Islands Na- percentage of breeders on the cliffs at a par- tional Wildlife Refuge obtained a vessel, the ticular time of day during a particular part of Aleutian Tern, which allowed visits to all the breeding season is not known. Auklet parts of the island chain. That year, nearly numbers are perhaps hardest to estimate. 36 P. C. SEKORA, G. V. BYRD, AND D. D. GIBSON

since swirling "clouds" of birds are en- unknown. countered. Figures 2-15 (pages 40-46) present data on Even when the estimates of birds seen are the distribution of populations of birds that assumed to be accurate, data interpretation is have survived the foxes and other introduced complex. Lack of information on diurnal predators. An annotated list of seabirds rhythms adds difficulty to data interpreta- breeding in the Aleutians follows. tion. Counts of burrow-nesting birds (e.g., puffins) have been inaccurately interpreted Annotated List of Species because of the lack of understanding of their Northern fulmar (Fulmarus glacialis) nesting ecology. Gulls {Larus spp.), terns, and jaegers (Stercorarius spp.) are not well known Northern fulmars breed on only three is- since shore parties have seldom investigated lands: Buldir (200 pairs), Gareloi (1,500 pairs), (more than pairs). island interiors. Nocturnal species (e.g., an- and Chagulak 100,000 cient murrelet, Synthliboramphus antiquus, Fulmars were apparently much more widespread formerly (Murie Turner and storm-petrels, Oceanodroma spp.) are per- 1959; 1886). haps the least known. Since only crude esti- Introduced foxes were probably involved in mates of colony sizes are available, broad the decline. limits are used in this paper to describe known Fork-tailed Storm-petrel and Leach's colonies. Storm-petrel {Oceanodroma furcata and O. leucorhoa)

Status and Distribution The distribution of storm-petrels is poorly of Breeding Seabirds known due to their nocturnal behavior near the nesting colonies. The presence of birds has Even from the sparse literature available, it generally been noted by finding them aboard is apparent that some seabird populations are ships anchored near islands after darkness. now drastically different from those in the Population estimates are not available for any Aleutians around 1900. Changes in nesting colonies, so symbols used in Fig. 3 indicate habitat due to volcanic eruptions, tidal waves, probable numbers of breeding birds. In few marine erosion, and earthquakes have oc- cases have active burrows or crevices been curred for centuries, and colonial nesting bird discovered. Storm-petrels were formerly populations have fluctuated accordingly. In much more common. Murie (1959) and John L. addition, native Aleuts used marine birds and Trapp (personal communication) found large their eggs for food and their skins for cloth- numbers of storm-petrel remains in fox dens. ing, but the Aleuts were so diminished in Most present breeding colonies are probably numbers by 1900 that they have had Uttle re- confined to offshore islets and fox-free cent effect on the bird populations. islands. From about 1900 to 1936, arctic foxes were Double-crested Cormorant, Pelagic introduced to most of the Aleutians for fur Cormorant, and Red-faced Cormorant farming. The foxes lived on birds in summer, (Phalacrocorax auritus, P. pelagicus, and some species (e.g., Aleutian Canada and P. urile) geese, Branta canadensis leucopareia) were wiped out wherever foxes were introduced. Double-crested cormorants breed as far Ground-nesting and some burrow-nesting sea- west as the Islands of Four Mountains. The birds were also drastically reduced or extir- colonies vary in size from a few to 25 pairs. pated on many islands. Pelagic and red-faced cormorants nest from During World War II the thousands of Amak to Attu on nearly every island. Relative troops in the Aleutians brought dogs and cats abundance of the two in mixed colonies varies to some of the islands as pets, and many of between areas as well as from year to year. the animals were set free when the men de- Red-faced cormorants tend to nest in colonies parted. The military also accidentally intro- mixed with kittiwakes and murres, but pure duced Norway rats to some of the islands. colonies also occur. Pelagic cormorants oc- Their role in seabird population reductions is cupy isolated, small colonies, but they also MARINE BIRDS IN THE ALEUTIAN ISLANDS, ALASKA 37

nest with kittiwakes and murres and are often Common Murre and Thick-billed Murre found with red-faced cormorants. By far the {Uria aalge and U. lomvia) densest concentration of cormorants occurs in Like kittiwakes, murres are abundant the Near Islands, especially at Attu, where an locally. A pure colony of either species is al- estimated 77,000 birds were seen in 1970. In most unknown, although one species often the Aleutians as a whole, red-faced cor- makes up more than 90% of a colony. Com- morants outnumber pelagic cormorants, and mon murres may have been reduced by foxes, double-crested cormorants make up only a since they tend to use sites with less slope very small percentage of the breeding than those used by thick-billed murres. At population. Bogoslof and the Baby islands, the birds use inland, gently sloping areas because there are Parasitic Jaeger (Stercorarius parasiticus) no foxes. The presence of the lichen {Caloplaca The distribution of jaegers is poorly known spp.), which according to Tuck (1960) is in- because investigators have spent little time dicative of bird roosts, on several extensive ashore on most islands. Murie (1959) found cliff areas suggests that either murres or kitti- jaegers on a number of islands, and most of wakes, or both, formerly used areas they do the data in Fig. 5 are his. Population esti- not use now. mates are available only for Amchitka (25 pairs; White et al. 1977) and Buldir (30-40 Pigeon Guillemot {Cepphus columha) pairs; G. V. Byrd, unpublished data). This species has been noted near almost every island that has been visited. Nesting Glaucous-winged Gull (Larus glaucescens) under beach boulders and driftwood, the birds Glaucous-winged gulls no longer nest on only occasionally are found in large concentra- islands where foxes occur except where tions (near Great Sitkin more than 4,000 birds islands in lakes are available. Most colonies were seen in 1971). Murie et al. (1937) summed are on offshore rocks or islets and range in up the distribution of pigeon guillemot accu- size from a few pairs to over 200 pairs, and rately: "Each island has its meager quota of occasionally more. They are found throughout these birds, nesting unobtrusively among the the Aleutians, but the largest known colonies rocks but never assembled in any really large are at Bogoslof (500 pairs) and Buldir (250 groups." Estimates of populations may be ex- pairs). tremely inaccurate because the diurnal rhythm of the pigeon guillemot is unknown. Black-legged Kittiwake and Red-legged Kittiwake (Rissa tridactyla and Marbled Murrelet and Kittlitz's Murrelet R. brevirostris) {Brachyramphas marmoratus and B. brevirostris) Black-legged kittiwakes breed locally in every major island group, usually mixed with Nests of neither species have been located murres and cormorants. The large colonies in the Aleutians, but nesting of both is sus- contain over 25,000 birds, but colonies of less pected at Adak, Unalaska, and Unimak, than 50 pairs also occur. Red-legged kitti- where specimens of Kittlitz's with brood wakes breed only on Buldir and Bogoslof. patches or eggs in the oviduct have been col- They are remnants of a previously more wide- lected in nearshore waters. Courtship has spread population. been recorded in marbled murrelets (Byrd et al. 1974). Arctic Tern and Aleutian Tern (Sterna paradisaea and S. aleutica) Ancient Murrelet {Synthliboramphus antiquus) Terns breed locally in each island group. Both species occur at Attu, Amchitka, Adak, The distribution of this species is very and Umnak, but only arctic terns are found at poorly known, since it is nocturnal near nest- Nizki. Factors limiting distribution are un- ing colonies. Murie (1959) wrote, "This is one known. Colonies vary in size from less than 10 of the species that undoubtedly has greatly pairs to 100 pairs. decUned in recent years, as a result of increase 38 P. C. SEKORA, G. V. BYRD, AND D. D. GIBSON

of the blue-fox industry." The leading of sites, so tufted puffins were more widespread downy young to sea by the adults is a very and numerous. However, in areas where ex- noisy process and foxes could easily take tensive talus slopes are available, horned large numbers. Also, these murrelets nest in puffins reached high densities. Predation by fairly shallow burrows which foxes could dig introduced foxes may have altered the distri- out easily. Birds were recorded near islands in bution of tufted puffins, which now nest pri- every group during surveys from 1972 to marily on fox-free islets just offshore from the 1975, but workers seldom went ashore to de- larger islands where foxes occur. The distribu- termine if they were nesting. In Fig. 12, the tion of horned puffins may not have been only basis for designating most of the areas altered significantly, since they are relatively marked as colonies is the presence of birds free from fox predation in their rock crevices. during breeding season (15 May-1 July). Recommendations Cassin's Auklet {Ptychoramphus aleuticus)

This is another species that was more com- A complete survey of the Aleutian Islands mon before the fox was introduced. Cassin's has not been done. This should be done, by auklet now seems to occur only locally, but methods that will provide accurate population these nocturnal birds are probably often over- estimates. Life history information is needed looked. They are known only from Buldir, on almost all species, and data should be Umnak, and the vicinity of Oglodak. gathered on selected populations to determine trends. Information on winter distribution Parakeet Auklet (Cyclorrhynchus psittacula) should also be compiled. The effects of introduced predators should be evaluated quanti- This auklet, which nests under beach tatively, and if control measures are needed, boulders, in burrows, and in rock crevices, effective, humane methods should be devised seems to use a greater variety of breeding and implemented. sites than do the other auklets. The largest known colony is at Chagulak, where an esti- Acknowledgments mated 10,000 were seen in 1972. Smaller colonies are found as far west as Buldir. The authors are grateful to the following Fish and WildUfe Service personnel Crested Auklet, Least Auklet, and Whiskered who helped collect previously unpubUshed data Auklet [Aethia cristatella, A. pusilla, used in this paper: E. P. Bailey, Craig- and A. pygmaea) C. S. head, C. P. Dau, M. H. Dick, G. J. Divoky, R. Aethia nest primarily in rock crevices of Martin, J. L. Trapp, G. W. Watson, and C. M. talus slides. Such habitat occurs locally in White. Most of the data were collected from each major island group except the Near the deck of the Aleutian Islands National Islands. Least auklets outnumber crested Wildlife Refuge research vessel Aleutian auklets in the Aleutians, and whiskered auk- Tern. Captain George Putney is acknowl- lets are far less common than either. Esti- edged for his peerless seamanship and con- mates of populations are probably grossly instant encouragement; he also contributed ob- accurate because of difficulty the both in esti- servations of birds. mating the number of birds in the milling The maps were adapted from a master sup- flocks observed and in interpreting the esti- plied by Elaine Rhode, Public Affairs Office, mates after they are obtained. U. S. Fish and Wildlife Service, Anchorage; she also suggested the use of squares to dis- Horned Puffin and Tufted Puffin {Fratercula play data. C. M. White graciously made his in- comiculata and Lunda cirrhata) press manuscript available. W. B. Emison, Horned puffins favor rock crevices in talus R. J. Gordon, and J. L. Trapp kindly made slides and cliff faces for nesting, whereas their field notes available, and Trapp helped tufted puffins are primarily burrow nesters. compile data. Most of the funds for the sur- The historical distribution of the two species veys in 1971-75 were provided by the U. S. was probably based on availability of nesting Fish and Wildlife Service, MARINE BIRDS IN THE ALEUTIAN ISLANDS, ALASKA 39

References Kenyon, K. W. 1961. Birds of Amchitka Island, Alaska. Auk 78:305-326. Lebedmk, P. A., F. C. Weinmann, and R. E. Norris. and E. E. C. Clebsch. 1971. Amundsen, C. C, Dy- 1971. Spatial and seasonal distributions of namics of the terrestrial ecosystem vegetation of marine algal communities at Amchitka Island, 21:619-623. Amchitka Island, Alaska. Bioscience Alaska. Bioscience 21:656-660. Bent, A. C. 1912. Notes on birds observed during a Murie, O. J. 1959. Fauna of the Aleutian Islands brief visit to the Aleutian Islands and Bering Sea and Alaska Peninsula. U. S. Fish Wildl. Serv., N. in 1911. Smithsonian Misc. Coll. 56(2): 1-29. Am. Fauna 61. 364 pp. V., D. D. Gibson, D. L. Johnson. 1974. Byrd, G. and Nelson, E. W. 1887. Report upon natural history The birds of Island, Alaska. Condor 76:288- Adak collections made in Alaska between the years 300. 1877 and 1881. U. S. Army, Signal Serv. Arct. Cahn, A. R. 1947. Notes on the birds of the Dutch Ser. Publ. 3. 337 pp. Harbor area of the Aleutian Islands. Condor O'Clair, C. E., and K. K. Chew. 1971. Transect 49:78-82. studies of littoral macrofauna, Amchitka Island, Clark, A. H. 1910. The birds collected and observed Alaska. Bioscience 21:661-664. during the cruise of the United States Fisheries Stejneger, L. 1936. George Wilhelm Steller—the steamer "Albatross" in the north Pacific Ocean pioneer of Alaska natural history. Harvard Uni- and in the Bering, Okhotsk, Japan, and Eastern versity Press, Cambridge, Mass. 623 pp. seas from April to December 1906. Proc. U. S. Sutton, G. M., and R. S. Wilson. 1946. Notes on the Natl. Mas. 38:25-74. winter birds of Attu. Condor 48:83-91. Dall, W. H. 1873. Notes on the avifauna of the Aleu- tian Islands, from Unalaska eastward. Proc. Taber, R. D. 1946. The winter birds of Adak, 48:272-277. CaUf. Acad. Sci. 5:25-35. Alaska. Condor Dall, W. H. 1874. Notes on the avifauna of the Aleu- Tuck, L. M. 1960. The murres. Ottawa. Canadian tian Islands, especially those west of Unalaska. WUdlife Series 1. 260 pp. Turner, Proc. CaUf. Acad. Sci. 5:270-281. L. M. 1885. Notes on the birds of the Near Islands, Alaska. Auk 2:154-159. Gabrielson, I. N., and F. C. Lincohi. 1959. The birds L. of Alaska. The Stackpole Co., Harrisburg, Penn., Turner, M. 1886. Contributions to the natural history of and Wildlife Management Institute, Washington, Alaska. U. S. Army, Signal Serv. Arct. Ser. Publ. 2. 226 D. C. 922 pp. pp. Hulten, E. 1960. Flora of the Aleutian Islands. J. White, C. M., F. S. L. WiUiamson, and W. B. Kramer, Weinham/Bergstr., Sweden. 376 pp. Emison. 1977. Avifaunal investigations. Pages Isakson, J. S., C. A. Sinensted, and R. L. Burgner. 227-260 in M. L. Merritt and R. G. Fuller, eds. 1971. Fish communities and food chains in the Environments of Amchitka Island, Alaska. U. S. Amchitka area. Bioscience 21:666-670. Energy Research and Development Association, Jones, R. D. 1949-1970. Annual refuge narrative re- Oak Ridge, Tenn. 682 pp. ports, Aleutian Islands N.W.R. Cold Bay, Wilson, R. S. 1948. The summer bird life of Attu. Alaska. (Unpublished administrative report.) Condor 50:124-129. 40 P. C. SEKORA. G. V. BYRD, AND D. D. GIBSON

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I aasi The Historical Status of Nesting Seabirds of the Northern and Western Gulf of Alaska

LeRoy W. Sowl

U. S. Fish and Wildlife Service 1011 East Tudor Road Anchorage, Alaska 99507

Abstract

The history of ornithological field work in the Gulf of Alaska dates back to 20 July 1741 and Bering's discovery of Alaska. In spite of this long history, the record is fragmentary and often seemingly contradictory. The coming of the tanker terminal at Valdez and the pending development of oil and gas resources on the outer continental shelf threaten massive change for seabirds in the Gulf of Alaska. Often overlooked, however, is the fact that man has already effected a

change in status for many of these birds. In this paper I examine the scanty, general record from the exploratory period, roughly 1741 to 1935, and the somewhat more comprehensive record of the reconnaissance period, 1936-74, and attempt to develop a basis for better understanding of the change in seabird status that has already taken place. This paper should be treated as a verbal model which can be improved as our knowledge of seabirds in the Gulf of Alaska is expanded.

From the perspective of history, 1970 program. Now in quick succession the Wilder- should prove to have been a momentous year ness Act and native land claims added new for Alaska and its seabirds. Two events, the urgency to the need for soUd resource infor- construction of the Trans-Alaska Pipeline and mation. More recently, the outer continental the passage of the National Environmental shelf minerals leasing program has made the Policy Act (NEPA) merged head on in 1970 quick development of base-Une information with the decision that Section 2c of NEPA ap- even more essential. plied to the proposed pipeUne. The systematic All of the new activity in Alaska's coastal appraisal of potential environmental impacts waters has the potential to affect seabirds in required by Section 2c quickly exposed the in- one way or another. We must remember, how- adequacy of the existing data base in many ever, that man's activities have been affecting areas. With respect to seabirds in the Gulf of seabirds for a long time. We cannot accu- Alaska, it was apparent that there had never rately assess the effect of a tanker terminal at been any effort to develop a synthesis of the Valdez or offshore oil activity without first information accumulated over 230 years. The developing some understanding of the current data gaps which were uncovered were ap- status of seabirds in the context of the histori- paUing. cal record. While the Trans-Alaska PipeUne impact Seabird work in Alaska can be divided statement had provided shock therapy, it was roughly into three periods. The first is the not the only influential event on the horizon. early historical or exploratory period; it ex- Two local disturbances had already preceded tended from Georg Steller's 1741 visit to the pipeUne. These were Project Chariot at Kayak Island to 1935. This was UteraUy a Cape Thompson and the Amchitka Island test period of exploration and the collection of in-

47 48 L. W. SOWL formation was dependent upon interest and History of Carolina, Florida, and the Bahama opportunity. The second is the reconnaissance Islands (Stejneger's annotated translation of period; during this period investigators were Steller's journal in Golder 1925). Collection of dispatched to a particular area to gather the bird confirmed for Steller that the first general information for management applica- Russian Expedition had reached America. tion. This period begins with Murie's exten- Steller was an accomplished naturalist, but sive investigations of the Alaska Peninsula his overbearing and superior manner had ap- and the Aleutian Islands; I see it extending parently sorely irritated Bering and his offi- from 1936 to 1975. In 1975 the need for data cers long before the expedition reached Kayak became so acute that it was necessary to enter Island. The seamen made little effort to go the third period, one of intensive data gather- ashore anywhere in Alaska and Steller was ing. Knowing where the big seabird colonies blocked from doing so as well. In addition to were located and knowing their general Kayak Island, he was able to go ashore only species composition was no longer adequate. on Nagai Island, first with a water party on The current intensive data-gathering effort in 30 August and again the next day. He noted the waters over oil and gas leasing areas is a that "all sorts of waterbirds in abundance partial response to the recognition of this were seen." These included two kinds of cor- inadequacy. morants, auks, ducks, gulls, divers, pigeon In this paper I draw some tentative conclu- guillemots (Cepphus columba), tufted puffins sions relative to the status of the 26 species of {Lunda cirrhata), and horned puffins (Frater- primary seabirds (Fisher and Lockley 1954) cula corniculata). breeding in, or which may have bred in, the Stejneger's comment on the identity of the northern and western Gulf of Alaska area. cormorants is interesting because, based on This area extends from Cape Fairweather, his experience, he assumed them to be pelagic 59 °N 138°W, westerly along the coast to Ika- and double-crested cormorants (Phalacro- tan Bay, 55 °N 163 °W, at the end of the corax pelagicus and P. auritus). He gave no Alaska Peninsula. These bird species tend to thought to red-faced cormorants (P. urile) be colonial, but not exclusively so. Two birds which are now common there. which are primary seabirds, the mew gull Steller noted on 6 September off Bird Island (Larus canus) and Bonaparte's gull (L. Phila- in the Shumagin Islands, that "when we were delphia), have not been included because they out to sea about half a mile we were especially tend to be more riverine than marine in habit. astonished at the untold numbers of seabirds Several marine ducks have been excluded be- which we saw on the northern side of the is- cause they are secondary seabirds. land." These birds were listed as cormorants, Information from the early exploratory auks, horned puffins, fulmars {Fulmarus gla- period is summarized under the next section. cialis), pigeon guillemots, black oyster- The more detailed information from the recon- catchers (Haematopus backmani), and a pied naissance period is discussed in the species diver which Stejneger assumed was an an- accounts. cient murrelet (Synthliboramphus antiquus). On 15 September when Bering's vessel, the St. Peter, was south of Amukta Pass, Steller Summary of the recorded observing "river gulls." The obser- Historical Record vation is not as interesting as Stejneger's comment (Golder 1925) concerning it. Stej- The history of ornithological field work in neger stated that no true river gulls lived in the Gulf of Alaska goes back 235 years to 20 the Aleutians and these must, therefore, have July 1741. On that day Bering's sur- been another small gull with red feet. He geon/naturalist, Georg W. Steller, spent a thought they must have been the red-legged scant 10 h ashore on Kayak Island. He col- kittiwake (Rissa brevirostris), which "in- lected a single bird. This bird, later named for habits the Aleutian Islands from Bering Is- Steller, reminded him of a plate of the blue jay land to Sannak." by Make Catesby, the colonial-era predeces- Thirty-seven years after Bering's voyage, sor of Audubon, in Volume 1 of the Natural Captain James Cook sailed into the Gulf of NESTING SEABIRDS OF THE GULF OF ALASKA 49

Alaska, arriving off Kayak Island on 11 May legged kittiwake {Rissa tridactyla) was com- 1778. Cook was not accompanied by an able mon at Round Island and Delarof Harbor, naturalist. His surgeon, William Anderson, Unga Island, in the Shumagins. The inference did have some experience gained on earlier is that it was more common at these two voyages in preparing skins and taking notes, places than elsewhere. The Arctic tern (Sterna but he had contracted tuberculosis and be- paradisaea) was abundant in the Shumagin came so ill that even his notes ceased after 8 Islands and particularly at Range Island in June, while the expedition was in Cook Inlet. Popoff Strait. Dall expressed the opinion that Cook was under orders to keep a careful rec- the horned puffin was very abundant in the ord of everything he saw. One of the results Shumagins and appeared to fill the niche of was that he had birds collected even though the tufted puffin, which he did not see there. he had no naturaUst to do the work. Several The only other bird which he thought to be birds were collected in Prince WiUiam Sound very common was the pigeon guillemot. He while Cook's vessels were at anchor in Port did not note the common murre {Uria aalge) at Etches. These included two marbled murre- aU. lets (Brachyramphus marmoratus— type In 1908 the second of three Alexander Ex- specimens), a black oystercatcher, a surfbird peditions conducted field work in the Prince (Aphriza virgata), a surf scoter [Melanitta per- William Sound area. From Dixon (1908) and spicillata), and a red-breasted merganser Grinnell (1910) we can derive some basis for (Mergus serrator—type specimen), along with assessing status in a very general way. The several forest birds (Stresemann 1949). most common seabird noted was the marbled The watch journals of Cook and his officers miu-relet. Glaucous-winged gulls and black- provide some additional information. Captain legged kittiwakes were common; the glau- Charles Gierke (Beaglehole 1974) remarked in cous-winged gull was the more common. his log on the passage out of Prince William Horned puffins were judged to be slightly Sound through Montague Strait on 20 May more common than tufted puffins by both that "it had almost become tautology to men- authors. The northern end of Montague Strait tion whales and seals and innumerable sea appears to have been the center of abundance fowl that so confoundingly kept their for puffins. Dixon noted that on 16 July 1908 distance." there were swarms of puffins in the channel Between the Trinity Islands and Chirikof along Green Island. Pigeon guillemots were Island on 18 June, Cook's men collected a conmion along the rocky coasts. Parakeet single tufted puffin. Later Cook passed close auklets {Cyclorrhyncus psittacula), common to the Semidi Islands and the Shumagin Is- murres, and ancient murrelets were noted lands and directly through the Sandman only in very small numbers.

Reefs. Beaglehole 's version of this part of the After the Alexander Expeditions there was voyage makes no mention of seabirds. another doldrum in which little was done. There is a gap of 87 years during which During this lull in activity, a note by Town- there is almost no hint of published material send (1913) appeared which compared the bearing on the status of seabirds in the Gulf numbers of crested auklets (Aethia cristatella) of Alaska. In 1865 the Russo-American Tele- at Yukon Harbor, Big Koniuji Island, to the graph Expedition touched this area. Dall and least auklets (A. pusilla) of St. George Island, Bannister (1869) provide us with a few scraps stating that the crested auklets were more garnered during that expedition, primarily by numerous. He sailed into the Yukon Harbor Bischoff. The glaucous-winged gull (Larus anchorage on the evening of 1 August and ob- glaucescens) was described as the most com- served that crested auklets "were present in mon species from California northward. myriads. The surface of the water was covered

Bischoff 's collections at Kodiak indicate that with them, and the air was filled with them." the horned and tufted puffins were collected The formal record available to researchers with ease. He was able also to collect an Aleu- is very shallow for this exploratory period. tian tern {Sterna aleutica—type specimen) With a few exceptions it was compiled by non- along with an egg. scientists, primarily explorers and egg and Dall (1873) noted in 1872 that the black- skin collectors. 60 L. W. SOWL

Current Status birds. We made a particular effort to visit Jude Island, between the Shumagin Islands Setting the Stage and the Pavlof Islands, because David This paper should be viewed as a conceptual Spencer (personal communication) had re- model. While I attempted to be as objective as ported once having seen the air over the island possible, subjectivity was unavoidable. Many filled with an extremely large number of of the tentative conclusions are based on very tufted puffins. However, there were no puffins little data. Each improvement will make it a at this colony either. better management tool. Because of the space Let us examine the facts in context. On 8 limitations, it is not possible to go into a de- June we had visited High Island where we had tailed tracking of my reasoning for each attempted to collect puffin eggs for pesticide species. In an attempt to overcome this handi- analysis, but had been able to find only one cap, I am including some examples of the egg. Also, there were only 6,000 tufted puffins sorts of reasoning that went into the process. where George Putney, master/engineer of the

In 1973 I led a Fish and Wildlife Service Aleutian Tern, had seen much larger numbers (FWS) reconnaissance survey team that was in 1972. These two facts could easily be re- delineating seabird colonies along the Alaska lated to explain the current situation because Peninsula. In the Shumagin Islands we en- it was still early in the breeding season. The tered or crossed Koniuji Strait twice (on 11 horned puffin observations in Koniuji Strait and 12 June) without even suspecting the (11-13 June) were in keeping with this conclu- presence of a horned puffin colony. A third sion also—an indication that these birds had passage through the strait (13 June) was not not yet settled down to a full breeding effort. so uneventful. The water and the air were The erratic comings and goings of common filled with horned puffins. This led to the dis- puffins (Fratercula arctica) early in the season covery that the 430-m mountain on the south- have been well documented (Lockley 1962). It eastern corner of Big Koniuji was also is an easy step to extend this reasoning to the covered with horned puffins, clear to its top. absence of birds at Bird Island on 11 June, The minimum estimate of the birds that were even though fresh signs of the characteristic visible was 140,000. Even this number of evidence of tufted puffin occupancy were birds would make this the largest horned missing. Jude Island provides a different clue, puffin colony ever discovered. David Spencer however. There were 3,000 pigeon guillemots, (personal communication) had noted similar an unheard-of concentration, apparently swarms of horned puffins in this strait in 1956 occupying abandoned tufted puffin burrows while flying sea otter surveys in the area. In on 15 June. Also, on 7 June we had made a 1975 a field camp was established at Yukon very interesting observation that had no Harbor, with study of this colony as one of the special significance at the time: murres on prime objectives of the investigators. As far Spitz Island were occupying little parapets as these investigators could tell no such large created by mashing down the mouths of colony existed there, even though the nesting puffin burrows which filled the slope above habitat was still there, unaltered. This sort of the cliff portion of their colony. event, one of the banes and vagaries of esti- After looking at all of the observations mating seabird numbers, is not rare. cited above, I conclude that tufted puffins In 1973, when FWS personnel delineated were greatly reduced in numbers on these the colony on the southwestern end of Bird Is- sites in 1973 and that they had been absent land in the Shumagins, there were estimated from the burrows used by the murres and to be 43,000 kittiwakes, 24,000 murres, and pigeon guillemots for more than the current 6,000 cormorants present; no tufted puffins breeding season. What causes these sorts of were seen about the colony. The last time (in changes? I do not know. 1970) one of the observers, Edgar Bailey, had One reason for year-to-year change may be visited the colony with Robert Jones, there local movements of colonies. Black-legged was an extremely large colony of tufted kittiwakes nest at several places in lower Orca puffins which Jones (E. Bailey, personal com- Inlet, Prince William Sound. Counts made at munication) estimated at more than 1 million these sites in 1972 and 1974 yielded almost NESTING SEABIRDS OF THE GULF OF ALASKA 51

identical totals but the numbers of birds dreds" of tapeworms in every bird. His con- varied between individual sites. This may be clusion was that their intestines were so an indication that all of these sites are part of solidly packed with tapeworms that starva- one large composite colony and that, at least tion was "an absolute certainty." in this colony and for this species, the birds Some apparent disruptions are long term. shift at will. In the Gulf of Alaska there is a hiatus in the The best record of population flux involving distributions of a number of small seabirds two species has been summarized by Peterson that are active around their colonies only at and Fisher (1955). In 1872 and 1873 the night. Repeatedly, the northern Gulf of murres observed on Walrus Island in the Alaska shows up as an area of reduced popula- Pribilofs were almost entirely common tion, as a boundary between subspecies, or as murres. In 1890 common and thick-billed a limit to a range. This same area has a notice- murres (Uria lomvia) were evenly matched in able lack of total darkness during a substan- number. By 1901 the colony was almost exclu- tial portion of the breeding season. sively dominated by thick-billed murres. In The nocturnal habit no doubt evolved be- 1911 and 1914 the few thick-billed murres cause it was advantageous to concentrate on present were almost lost among the then the breeding grounds only under the cover of dominant common murres. In 1940 thick- darkness, when diurnal predators were at a billed murres dominated again. When Peter- great disadvantage. Cody (1973) states that son and Fisher visited the island in 1953, the Cassin's auklet {Ptychoramphus aleuticus), situation was again reversed and common which is strictly nocturnal around its colonies, murres had almost completely replaced the avoids these colonies on brightly moonlit thick-billed murres. These changes are even nights. He sees this as an apparent response more impressive because of the number of to gull predation. At higher latitudes the birds involved, between 1 and 2 million in small alcids have overcome this disadvantage 1953. There are more tenuous indications that by swamping predators through their sheer somewhat the same thing may occur between numbers. In the Gulf of Alaska I suspect that two other congener pairs, the pelagic and red- few of the small seabirds, except possibly the faced cormorants and the black-legged and fork-tailed storm-petrel (Oceanodroma fur- red-legged kittiwakes. The causative factor, cata), have ever achieved great enough num- or factors, is not readily apparent. One possi- bers to offset the impact of extended daylight. bility is long-term cUmatic fluctuation. Past disruptions of seabird populations are Dement'ev and Gladkov (1966) provide an both natural and man-induced; however, the example of abrupt and massive change. Be- documentary record is much too fragmentary fore 1876, the pelagic cormorant abounded on to allow us to fully appreciate what has oc- the Commander Islands. During the winter of curred or what the long-term effect has been. 1876-77, the birds were decimated by an un- To give some perspective to the problems as- known epizootic disease. By spring only a few sociated with assessing change and attempt- individuals remained alive. The record shows ing to understand it, some of the indicators of that by 1882 they were already becoming natural and unnatural change and flux in sea- common again. Red-faced cormorants were bird populations are reviewed here. apparently not reduced in number because The flux in- bird numbers can be related to Dement'ev and Gladkov (1966) state that the time of day, season of the year, and atmos- they were common in "the second half of the pheric conditions on a short-term basis. This last century and the beginning of this." Did sort of flux or apparent flux can easily be ex- they flourish only while the pelagic cor- plained. The underlying cause of some of the morants were reduced in number? longer term flux is not so easily arrived at. Bowles (1908) gives another indication of Murie (1959), Gabrielson and Lincoln (1959), naturally induced population impact. He and Sowl and Bartonek (1974) have noted noted large numbers of dead seabirds on some of the man-induced changes. These are Washington beaches and the ocean "rather also explored to some extent in the species ac- plentifully dotted with sick birds ..." He counts as they are found to apply. examined some birds and found "many hun- I sometimes refer to a colony size class 52 L. W. SOWL when discussing the existing data rather than ment of birds through Shuyak Strait from to an actual population estimate. The size Shelikof Strait into the Gulf of Alaska. It was classes used are defined as follows: not determined whether the fulmars were Class I—less than 100 birds moving with the shearwaters or on a regular Class 11-100-1,000 feeding flight. Fulmars are often found close Class 111-1,000-10,000 to Afognak Island in the area between Sea Class IV- 10,000-100,000 Lion Rocks and Sea Otter Island. Gabrielson Class V-100,000-1,000,000 and Lincoln (1959) reported seeing swarms of Class VI—more than 1,000,000 fulmars in Marmot Strait and around the The Dictionary of Alaska Place Names small islands on the north side of Afognak in (Orth 1967) is the reference for those who wish early August. Murie (1959) noted fulmars in to locate some of the less obvious sites. The Shelikof Strait and again around the Shu- Coast Pilot, No. 9 (U. S. Department of Com- magin Islands. There is nothing in this record merce 1964) is another useful reference. to indicate any change in their distribution at sea recently. The Semidi Islands support the Gulf of Species Accounts Alaska's largest fulmar breeding population, a Class V colony (U. S. Bureau of Sport Northern Fulmar {Fulmarus glacialis) Fisheries and Wildlife 1973). Gabrielson and Petrels of a number of species can be found Lincoln (1959) considered it to be one of the in the Gulf of Alaska, some of them in great four largest colonies in Alaska. numbers. Only the northern fulmar breeds Gabrielson (1940) was told by Captain Selle- there. vold of the marine vessel Brown Bear that he The fulmar is common in the offshore thought the birds nested on Sea Otter Island waters of the northern Gulf of Alaska in Perenosa Bay. Gabrielson also learned that throughout most of the year (Isleib and they probably nested on Sea Lion Rock at the Kessel 1973). Most authors, including Clark head of Marmot Strait. In August 1973 I ob- (1911), one of the earlier ones, who commented served fulmars in close proximity to Sea Lion on the distribution of fulmars farther out in Rock. More recently, small numbers of ap- the Gulf, have considered them to be abun- parently breeding fulmars have been found in dant. Nichols (1927) raised one of the few the Barren Islands (L. W. Sowl, personal ob- voices of apparent dissent; he noted that in servation and Edgar Bailey, unpublished 1926 he encountered the largest number of FWS report. Anchorage, Alaska). Although fulmars (about 800) on 11 July in Shelikof no other colonies are known or suspected, the Strait after he had left the Gulf. During the evidence suggests the possible existence of summer, fulmars are very common seaward of some. Montague Island, particularly to the north- Peterson and Fisher (1955), on noting dark east of Patton Bay and in the approaches to fulmars between St. Paul and St. George Montague Strait. Data derived from FWS when only the light morph was present on any surveys in July and August 1972 showed an of the colonies in the Pribilofs, expressed no estimated 10,000 fulmars in a stretch of surprise. They offered the opinion that a waters 19 km wide along the east side of Mon- round trip of 960 km to one of the dark morph tague Island (Isleib and Kessel 1973). colonies in the Aleutians just might be within Over the Portlock Banks and in Stevenson the operating range of a fulmar on a 4-day Entrance, fulmars sometimes concentrate in vacation from nest-tending duties. Using this very large numbers, either by themselves or in as a general yardstick, it appears that the rich company with sooty shearwaters (Puffinus foraging grounds over the Portlock Banks griseus). In August 1973, FWS observers might also be within the range of breeding ful- crossing Perenosa Bay saw large numbers of mars from the Semidis. The trip up Shelikof tube-nosed birds moving northeastward Strait and on to Portlock Bank by way of across the Bay. Although these appeared to Shuyak Strait is only slightly longer than the be predominantly shearwaters, there were one from Chagulak to St. Paul. The feeding also many fulmars. There was a general move- grounds off Montague Island would require a NESTING SEABIRDS OF THE GULF OF ALASKA 53

1,600-km round trip from the colonies in the James W. Brooks (personal communication), Semidi Islands. Birds from the Barren Is- M. E. Isleib and I anchored at Fish Island in lands and any colonies around Shuyak Island the Wooded Islands. We did not locate any could easily reach the Montague Island storm-petrel burrows, but a steady flow of grounds, but why would they cross the Port- storm-petrels passed over the boat through- lock Banks to do so? out the darkest part of the night. Surveys Fulmar colonies may be found in the Chis- conducted at about that time provided an es- well Islands. It is also a possibihty that the timate of 19,000 fork-tailed storm-petrels in existence of colonies on islands along the Prince William Sound, primarily in or close to north coast of Afognak Island will be verified Montague Strait, and in coastal waters on the and that others will be found in the vicinity of east side of the Sound's outer islands. In this Shuyak Island. Gabrielson and Lincoln (1959) area Isleib (personal communication) has expressed the opinion that there is almost cer- noted a general movement of fork-tailed tainly a colony on Sutwik Island. If there is storm-petrels westward around Montague Is- one, however, I did not see it on one quick trip land and into Prince William Sound through around the island in 1973. Montague Strait each morning and a corre- Gabrielson (1940) expressed surprise at the sponding countermovement each evening. I size of the Semidi Island breeding colony. conclude that in 1972 there was a Class IV Gabrielson and Lincoln (1959) considered colony in the Wooded Islands, numbering be- 1911 to be the first time breeding fulmars tween 19,000 and 38,000 birds. Additional were found in the Shumagins. They ap- colonies will be discovered in a similar manner parently based this on two eggs collected as more systematic searches are made. there that year and documented in a plate in No colonies were discovered during the 1973 Bent (1964). Other than Gabrielson's opinion, reconnaissance survey of the islands south of there is nothing to indicate a major change in Alaska Peninsula. Working primarily inshore, fulmar status during this century. If there has FWS investigators encountered very few been a change in status, it has probably been storm-petrels during the day. On the night of in the direction of increasing populations. 14 June, the FWS vessel, Aleutian Tern, re- sponded to a Mayday call and was either in Fork-tailed Storm-petrel (Oceanodroma transit or participating in rescue operations furcata) from 2245 to 0420 h on the morning of 15 The fork-tailed storm-petrel probably June. During this period numerous fork-tailed breeds throughout the Gulf of Alaska. It is storm-petrels were encountered, particularly abundant at sea during the summer in most off Cape Wedge on Nagai Island. After we offshore waters. Murie (1959) described it as anchored in Eagle Harbor on Nagai, more the dominant petrel in the Bering Sea and the storm-petrels were heard about the vessel. North Pacific. At about this same date. National Marine In view of its wide distribution and ap- Fisheries Service enforcement officers flying parent abundance very little is known about fisheries patrols observed storm-petrels in the fork-tailed storm-petrel's breeding colo- abundance south of the Shumagin Islands nies. Friedmann (1935) recorded specimens (James Branson, personal communication). and eggs from Kodiak dating back to 1843. These observations support the belief that Murie (1959) noted them as nesting on Sanak there are probably substantial undiscovered Island and stated that they almost certainly colonies in the Shumagin Islands. nested in the Shumagins and on other islands Fork-tailed storm-petrels are abundant along the Alaska Peninsula. David Roseneau summer residents in the northern Gulf of (Isleib and Kessel 1973) found this storm- Alaska and the estimate by Isleib and Kessel petrel "breeding by the 10,000's" on East (1973) is that populations using the waters off Amatuli Island in the Barren Islands in June the North Gulf Coast probably number in the 1965. This was subsequently verified in 1974 millions. Certainly the same estimate is valid by Edgar P. Bailey (unpublished report, FWS, for the rest of the Gulf area west of the Chu- Anchorage, Alaska). gach Islands. On 2 July 1972, responding to a tip by The status of these birds relative to their 54 L. W. SOWL

historical abundance cannot be derived from to the introduction of fox. No systematic as- the existing information. There is strong sus- sessment of seabirds on Sanak has been at- picion that the introduction of fox on many of tempted since Littlejohn 's time. the islands in the area during the early part of No Leach's storm-petrel colonies have been this century probably caused a reduction in encountered during reconnaissance surveys of their numbers. Murie (1959) said that experi- the Gulf of Alaska. Small numbers have been ence taught him that wings left from fox kills reported from time to time and while it is very or remains of storm-petrels in fox droppings much less abundant than the fork-tailed could be accepted as evidence of the presence storm-petrel, I expect that it will be found in of a colony. Gabrielson and Lincoln (1959) re- small numbers at various places in the Gulf of ported that E. P. Walker visited the Wooded Alaska when it becomes possible to make Islands in 1922 searching for a storm-petrel more thorough searches. It may occur in re- colony that had been reported to exist there in mote areas like the smaller islands scattered 1918. He could not find it even though he throughout the Sandman Reefs—possibly searched diligently. This apparent disap- even in large numbers. On the basis of the pearance was attributed to the introduction of Sanak record, we must assume that this fox. storm-petrel has been greatly reduced in num- There is another factor to consider, how- bers, at least in the western portion of the ever. The limited number of specimens now Gulf. available from the Gulf of Alaska indicates that separate subspecies occupy the eastern Double-crested Cormorant {Phalacrocorax and western Gulf of Alaska. The accepted auritus) boundary is somewhere in the vicinity of The white-crested cormorant, the race of Prince William Sound. This is an indication the double-crested cormorant residing in the that there has been a hiatus in this area of Gulf of Alaska, is principally an inhabitant of rather long duration. I have speculated that the marine environment. This cormorant is a this sort of break may be in some way related common, but apparently patchily distributed, to the length of day and a period during the resident throughout the northern and western summer when there is little darkness to cover Gulf of Alaska. activities near the colony. Thoresen (1964) Gabrielson and Lincoln (1959) thought that and Cody (1973) have both reported that west- it nested only from Kodiak Island westward ern gulls {Larus occidentalis) assemble in into the Aleutians. However, it probably Cassin's auklet colonies on moonUt nights to breeds from Yakutat Bay westward. Isleib prey on arriving adults. It is likely that other and Kessel (1973) estimated the abundance of nocturnal species would provoke the same the double-crested cormorant along the North sort of hunting tactic. A light-related preda- Gulf Coast as several thousands, about one- tion factor implies that the predators rely on tenth as common as the pelagic cormorant. It sight. Avian predators are indicated. is the third most abundant of the four cormorant species nesting in the area. It occurs Leach's Storm-petrel as scattered inclusions in many colonies {Oceanodroma leucorhoa) throughout the area, and at least in the Shu- Even less well understood than the breeding magin Islands, even occurs in some colonies distribution of the fork-tailed storm-petrel is by itself. that of Leach's storm-petrel. There are no data on which to base an esti- Bendire (1895) quotes notes from Chase mate of any change in status. It probably is Littlejohn, who found Leach's storm-petrel to not much affected by many of the naturally be an abundant breeder on unspecified small occurring perturbations. islands near Sanak in 1894. It greatly outnumbered the fork-tailed storm-petrel. On his Brandt's Cormorant (Phalacrocorax visit in 1937 Murie (1959) learned that all of the large colonies of seabirds that had once penicillatus) existed there were gone. He attributed this to On 22 July 1972, 13 Brandt's cormorants (4 overfishing and associated perturbation and sitting on nests) were found at Seal Rocks in NESTING SEABIRDS OF THE GULF OF ALASKA 55

Hinchinbrook Entrance, Prince William the Kodiak Archipelago impose some logis- Sound (Isleib and Kessel 1973). Two years tical requirements which discourage all but later I positively identified two individuals in the most determined birders. Not many have breeding plumage among a mixed group of been able to reach more than very limited seg- cormorants in the Chiswell Islands west of ments of the entire coast. Given the vast dis- Seward. Are these recent range extensions? tances involved, few of the FWS vessels pass- Possibly, but I propose an alternative ex- ing through the area have had the time to planation. thoroughly examine any cormorant colonies Palmer (1962) showed the distribution of or roosts bird by bird. Even for those who this cormorant as breeding north to Puget pause, the ever present swells and the con- Sound and as a straggler north to Forrester stant chop of the summer westerlies make Island, Alaska. This viewpoint is shared by positive identification difficult. the American Ornithologists' Union (1957), It is possible that Brandt's cormorant has which regards the bird as casual as far north been in the area in small numbers for a long as Forrester Island, where this species was time, either regularly or intermittently. It collected by Willet (1918). could have escaped observation because of the Let us look at the other record, the one that conditions described above. This species may is not supported by specimens. Bent (1964) be there as a relict, as a pioneer, or only be- thought of Brandt's cormorant as a breeding cause surplus birds are being pushed into resident of Forrester Island. Gabrielson and marginal habitat by population pressures on Lincoln (1959) admonished bird observers to their main range to the south. be on the lookout for this particular cormorant in the vicinity of Ketchikan and Pelagic Cormorant (Phalacrocorax pelagicus) Prince of Wales Island. Brandt's cormorant also appears on the bird list for the Kodiak The pelagic cormorant is the most abun- National Wildlife Refuge as an accidental dant of the four cormorants residing in the visitor. Gulf of Alaska. It is found throughout coastal Early observers like Bent were explorers. Alaska south of the Bering Strait and even in They carefully examined and made notes on some colonies in the southern Chukchi Sea. all the birds they saw because there was al- Cormorants have a certain invisibility ways a chance of a new discovery. It is also which is brought about by their universal very probable that Bent paid particular atten- presence. This blindness appears to have af- tion to the cormorants when he was at a place fected everyone, even the earliest observers. like Forrester Island. He would have un- The earliest accounts provide a composite doubtedly been very interested in trying to picture of the distribution and abundance of confirm the presence of the now extinct the pelagic cormorant which is very similar to Palla's cormorant (P. perspiculatus), as he that encountered today. In southeastern must have been aware of Schlegel's (1862-64) Alaska, beginning at the eastern edge of the list of the birds in the Dresden Museum since area under discussion, the pelagic cormorant

Willet (1914) had recently referred to it. The was pictured as the sole resident cormorant. staffs for the Kodiak and Aleutian Islands However, we know from Willet 's collection of National WildUfe refuges have included some a Brandt's cormorant at Forrester Island that very careful observers, such as Frank Beals. this might not be quite true. From Yakutat These men would have noticed the difference Bay westward into the Aleutians this species if a new bird such as Brandt's cormorant was coexisted with the double-crested cormorant. seen, verified the sighting visually, and then In the Western Aleutians there is some dis- noted it in their field diaries. They would not agreement, but in general it appears to have have bothered to develop the type of proof been accepted that the red-faced cormorant needed for an undisputable record, but the occurred there along with pelagic and pos- bird would have appeared in the refuge bird sibly double-crested cormorants. In the list (as it does). Bering Sea this species coexisted with the red- The outside coasts of the Alexander Archi- faced cormorant. pelago, Kenai Peninsula, and the Islands of A number of recent authors (Gabrielson 56 L. W. SOWL

1940, 1944; Murie 1959; and others) have con- Turner (1885) reported that the double- sidered the pelagic cormorant to be the most crested cormorant was abundant in the Near widely distributed and abundant of the four Islands and that the pelagic cormorant was species found in Alaska. Since the modern pic- common, but makes no reference to the red- ture fits, in a general way at least, it would be faced cormorant. One specimen of the latter in easy to conclude that the species enjoys an the Leningrad Academy of Science was taken unchanged status. There is just a faint sug- at Attn on 16 September 1844 (Gabrielson gestion that this may not be true. and Lincoln 1959), which indicates that they Dement'ev and Gladkov (1966) refer to a were probably present during the period re- great die-off of pelagic cormorants referred to ported on by Turner and, therefore, relatively earlier, in the Commander Islands. Stejneger uncommon. Clark (1911) identified red-faced (1885) enlarges on this disaster. It is true that cormorants only a few times and in the Aleu- Stejneger visited these islands a relatively tians only once, near Agattu. Dall (1874) short time after the die-off, but he reported noted two red-faced cormorants collected at that even though the pelagic cormorants were Amchitka but he (Dall 1873) apparently did increasing, "people having seen their former not see any east of Unalaska. multitude think that there is no comparison Nelson (1887) apparently found red-faced between the past and the present." Murie cormorants breeding on the Siberian and (1959) thought that the pelagic cormorant, Alaskan mainlands at either side of Bering while numerous, was outnumbered by the red- Strait, but Bailey (1948) searched for some faced cormorant in the Aleutians. More re- sign of their presence and found none. Nelson cently there has been the rapid eastward ex- (1887) also reported the red-faced cormorant pansion of the red-faced cormorant. Although from St. Matthew and St. Lawrence islands in it is not possible to determine what the real the northern Bering Sea and from St. Michael status of the pelagic cormorant is relative to and Nelson Island on the Alaskan coast. its past status, I conclude that during this Gabrielson and Lincoln (1959) pointed out century its status relative to that of the red- that it has not been found breeding north of faced cormorant has declined. the Pribilofs since then. Friedmann (1934) provides support for Nelson by reporting red- {Phalacrocorax urile) Red-faced Cormorant faced cormorant bones from archeological The red-faced cormorant, in spite of super- sites on St. Lawrence. Gabrielson and Lincoln ficial similarities to the pelagic cormorant, (1959) cited two red-faced cormorants in the just does not look the same to an experienced Leningrad Academy of Science which were observer. However, it would have been pos- collected in the Pribilofs in 1843. Dall and sible for inexperienced observers in the days Bannister (1869) reported them to be plentiful before modern optics to overlook the differ- on St. George Island. Baird (1869) also noted ences. The problem was further compounded their presence in the Pribilofs. by the "invisibility" of the ubiquitous cor- Bent (1964) makes no mention of seeing the morants referred to earlier. Apparent ab- red-faced cormorant in the Aleutians. He sences or blank spots in their range may not gives their breeding range as the Bering Sea have been real. region, the Pribilof Islands, and perhaps the Dement'ev and Gladkov (1966), reporting western Aleutians, the Commander Islands, on the Russian record, stated that the red- and the coast of Siberia north of North Cape. faced cormorant was common in the Com- The American Ornithologists' Union (1931) mander Islands during the last part of the gave their breeding range as the Pribilof Is- 19th century and into the early part of the lands, the Commander Islands, and Siberia 20th. Older authors had also reported it from north to North Cape. Kamchatka and the Kurile Islands. Now, ac- Murie (1959) found a colony of between cording to Dement'ev and Gladkov, it is an 4,000 and 5,000 red-faced cormorants nesting uncommon breeder on Mednyi Island in the on Amak Island in 1925. In 1936 he was sur- Commander Islands and occurs only as an prised to find that the red-faced cormorant autumn visitor to some of the southern Kurile was the most abundant breeding cormorant in Islands. the Aleutian Islands. Pelagic cormorants still NESTING SEABIRDS OF THE GULF OF ALASKA 57

appeared to be most numerous, but there were or north of the Pribilof Islands. large numbers of nonbreeding birds. In 1936 The fragmentary record appears to show a he located "a good sized colony" of red-faced long-term perturbation in the range and popu- cormorants at Unga in the Shumagin Islands. lations of the red-faced cormorant that covers He found about 300 birds starting their nests at least 100 years. I believe that we are prob- on 16 May. ably seeing a recovery of lost range and a re- In August 1946 Gabrielson (Gabrielson and turn to something resembling a former distri- Lincoln 1959) visited the colony at Delarof bution and abundance. Harbor, Unga, where several thousand cor- What caused the perturbation? I am not morants were observed. From a number of prepared to answer this question, but there small samples he estimated that the red-faced are two occurrences which I find suggestive. cormorants outnumbered pelagic cormorants It is interesting to note (Dement 'ev and five to two. In 1973 I observed about 2,000 Gladkov 1966) that on the Commander Is- cormorants, mostly red-faced, in this colony. lands the red-faced cormorant was most abun- Gabrielson also located them at two other dant during the first 50-odd years after the sites in the Shumagins and at Aghiyuk Island pelagic cormorants had been wiped out in the in the Semidi Islands. winter of 1876-77. Perhaps some clues are to Howell (1948) noted only double-crested cor- be found in the interactions between these morants at Double Island, Kodiak. Shortly similar species. after that the leaflet, Birds of the Kodiak Is- It does not appear that the introduction of land National Wildlife Refuge (first issued in fox could have been a causative factor. The 1955), listed red-faced cormorants as common first observations of population expansion summer residents. The red-faced cormorant were noted almost concurrently with the hey- was next found at Katchemak Bay about day of the fox-farming industry. Because of 1963. Isleib (Isleib and Kessel 1973) first its choice of nesting habitat (very steep cliffs), noticed red-faced cormorants wintering in this cormorant would not have been affected Prince William Sound in 1969. In July 1972 by predators except for the one that went into Isleib and Sowl had found a colony containing a very rapid population decline at a time that 75 nests at Point Elrington at the western ap- would fit—the Aleut. proach to Prince William Sound. By 1974 Jochelson (1968) and Hrdlicka (1945) sum- Isleib and Haddock (unpublished data, FWS, marized references to Aleut clothing in the Anchorage, Alaska) found them east of the diaries and reports of early Russian visitors Copper River Delta at Wingham Island. to the Aleutian Islands. Evidently Aleut The relatively rapid expansion of the range women sometimes wore a long, robe-like and apparent population size of the red-faced parka made of harbor seal (Phoca vitulina) cormorant is remarkable. But has this been a skins or, for women of high rank, parkas made real expansion into vast stretches of new ter- of sea otter (Enhydra Intra). The men in al- ritory? The record in the literature which I most all reports were said to have worn bird- have summarized shows, I think, something skin parkas; puffins and guillemots appear to else. We can demonstrate a historical range have been preferred, but cormorants were for the red-faced cormorant that extends on sometimes used. It took about 40 puffin skins the Asiatic Coast from North Cape, Siberia, to fabricate a parka and a man evidently south to the Kurile Islands, the entire Aleu- needed from one to three of these garments tian Arc including the Commander Islands, each year. all the Bering Sea islands north to Bering Sea otter populations were drastically re- Strait, Norton Sound, Nelson Island, and the duced by Russian hunters. Rats were intro- islands south of the Alaska Peninsula at least duced to the Aleutians very early during the as far east as Kodiak Island. The recently Russian period and must have had a substan- occupied coast from Cook Inlet to the Copper tial impact on populations of tufted puffins River may represent a real range extension. and guillemots. The introduction of fox would The breeding range of this species at the have had a further impact on burrow-nesting present time does not include parts of its his- birds. Turner (1885) noted that Aleuts in the torical range west of the Commander Islands Near Islands kept the fox confined to Attu so 58 L. W. SOWL that they could keep the fox away from the Two glaucous-winged gull concentrations birds on Agattu. This is evidence of an Aleut stand out in the northern Gulf of Alaska. One recognition of serious competition. Could cor- of these is on Egg Island at the western end of morants, particularly red-faced cormorants, the Copper River Delta. Patten (1976) esti- have been preferred sources of fiber? Were mated that this colony contained 10,000- Aleuts forced to rely more heavily on cor- 12,000 gulls in 1975. At times it appears to morant skins as puffin and guillemot numbers spread onto nearby Hinchinbrook Island. were reduced by rats and fox and sea otters M. E. Isleib (personal communication) has es- by men? timated its size as high as 25,000 gulls. The Whatever the cause and effect, the status of other large concentration is on the Susitna red-faced cormorants now appears to be Flats across Cook Inlet from Anchorage. This better in the Gulf of Alaska than for at least colony, or colony cluster, may be larger than the last 100 years. the one at Egg Island. There are no other known colonies even approaching these in size. Most colonies range between a few pairs Glaucous-winged Gull (Lams glaucescens) and 2,000-3,000.

The glaucous-winged gull is apparently one Glaucous-winged gulls do not appear to of the more successful seabirds breeding in have had any great changes in population the Gulf of Alaska. While it is outnumbered that can be detected from the literature. (both locally and in total abundance) by the There have almost certainly been local fluc- black-legged kittiwake, it is generally the tuations in the number of breeding birds as most conmionly seen and most uniformly dis- food suppUes, such as canneries and dumps, tributed gull in the Gulf of Alaska. Murie have appeared or disappeared in an area. (1959) called it the common breeding gull Long-term changes in salmon runs have un- about the Alaska Peninsula. Cahalane (1943, doubtedly had an impact as well. One other 1944) considered it to be numerous to abun- change, the reduced level of egging, has un- dant around Kodiak and in the Shelikoff doubtedly had an effect also. Along the Strait area. Gabrielson (1944) reported that it Alaska Peninsula and in the Shumagin Is- could be seen in small numbers everywhere. lands, cannery workers of FiUpino heritage Most recently, Isleib and Kessel (1973) re- and fishermen who have a strong Aleut heri- ported it to be an abundant resident in the tage stiU harvest gull eggs for food. However, north Gulf Coast area. My own experience this activity is much reduced from what it would confirm these observations. must have been. This gull appears to use a wider variety of nesting sites than some others (Gabrielson Herring Gull (Larus argentatus) and Lincoln 1959). Except where man's activities have created new food sources, there ap- The herring gull is a resident of Upper Cook pears to be a close link between the location of Inlet and is found up and down the coast from glaucous-winged gull colonies and those of Prince William Sound to the Alaska Penin- murres, kittiwakes, and cormorants. Swartz sula. Not too much was learned about it dur- (1966) found that during the breeding season ing the recent FWS reconnaissance. WilUam- glaucous-winged gulls at Cape Thompson de- son and Peyton (1963) reported the inter- rived almost all of their food from murre eggs breeding of herring gulls and glaucous-winged and chicks. I have noted small numbers of gulls in this area. This interbreeding has re- these gulls nesting, usually on turf near the sulted in a situation in which assignment of tops of cliffs, in most colonies of favored prey these gulls to one group or another in the field species. can be rather arbitrary. The result has most The glaucous-winged gull is the principal often been that field observers tend to lump scavenger throughout much of coastal south- them with glaucous-winged gulls unless their central Alaska. This has sometimes resulted herring gull characteristics are obvious. in the development of large concentrations Specimens collected by Williamson and Pey- near canneries and, more recently, near ton (1963) indicate that herring gulls have the diunps. edge in numbers in Upper Cook Inlet. NESTING SEABIRDS OF THE GULF OF ALASKA 59

Black-legged Kittiwake (Rissa tridactyla) turbation over the past 40 years. Before 1936, the record is too fragmentary to allow an

The black-legged kittiwake is the most assessment. abundant gull in the northern and western One of the interesting aspects of kittiwake Gulf of Alaska. Colonies of this species can be ecology in the Gulf of Alaska is the common found throughout the entire area, and range occurrence of breeding failure. David Snarski in size from a few pairs (Class I) to more than (December 1943 Quarterly Progress Report, 100,000 birds (Class V). They may be found in Alaska Cooperative Wildlife Research Unit, essentially pure colonies, but are often found University of Alaska) observed breeding fail- sharing colonies with murres. ure on colonies in the Tuxedni National Wild- The center of abundance for breeding black- life Refuge in 1970 and 1971 and obtained cir- legged kittiwakes in the Gulf of Alaska is in cumstantial evidence of another failure in the Semidi Islands, where Palmer Sekora 1972. In 1973 all of the breeding cliffs were (U. S. Bureau of Sport Fisheries and Wildlife occupied and nesting was successful. What- 1973) estimated that there were 426,000 ever the cause of these periodic failures, they breeding kittiwakes in 1972. He located kitti- do not yet appear to have had a permanent wake colonies at eight sites, ranging in size impact that we are able to measure. from 1,000 to 109,000 nesting birds. The size of the average colonial site was 27,000 birds. Red-legged Kittiwake (Rissa brevirostris) Ten sites were Class IV in size and one was a solid Class V. Red-legged kittiwakes are not now known The easternmost known colony in the north- to breed in the western Gulf of Alaska. Turner ern Gulf of Alaska is at Wingham Island. Up (1886) stated that he saw a few at Sanak in to 1973, 22 colonies had been located in Prince 1878. We also have Stejneger's (1885) state- William Sound. The largest of these contained ment, that "red-legged" kittiwakes nest from only 5,636 nests in 1972 (Isleib and Kessel Bering Island to Sanak. Friedmann (1937) re- 1973). Class IV or larger colonies are found at ported two humeri from Kodiak Island Cape Resurrection, the Barren Islands, Chisik middens. During the summer of 1976, two Island, Boulder Bay and Cape Chiniak on birds were observed off Kodiak Island by Kodiak Island, and at Delarof Harbor and the Irving M. Warner (personal communication), Haystacks in the Shumagin Islands. It is in- and one at 158°W and 54°30'-54°20'N south teresting to note that Gabrielson (1940) con- and east of the Shumagin Islands (Patrick J. sidered Whale Island to be one of the largest Gould, personal communication). known kittiwake colonies in Alaska. He stated Turner (1885) listed the red-legged kitti- that there were many thousands of pairs ex- wake as abundant and breeding in the Near tending over a mile or more of cliff. He saw a Islands. Turner (1886) also stated that he had second site which he did not visit but looked seen quite a number about a cliff back of the equally large. A photograph in an article by village on Akutan Island in 1878. He added East (1943) also indicated the presence of a that to the westward this kittiwake was more large colony. C. J. Lensink (personal com- abundant than the black-legged kittiwake. munication) estimated that there were about Murie (1959) expressed the opinion that 100,000 kittiwakes in the colony in 1956. Turner had CMifused the short-billed gull with When last visited by Vernon Berns (personal the "short-billed" kittiwake. Clark (1911) also communication), this colony contained only reported that he had seen the red-legged kitti- 3,000 birds. It is also of interest that Gabriel- wake in small numbers near Unalaska and son (1940, 1944) did not notice either the kitti- that they became progressively more common wakes or the murres now breeding on Nord Is- west to the Near Islands. Nelson (1887) re- land in the Barren Islands or the kittiwakes ported seeing large numbers of red-legged on East Amatuli Island. kittiwakes at Unalaska. Murie (1959) and Whale Island and possibly the colonies in Gabrielson (1940, 1944) did not see any red- the Barren Islands give evidence of local legged kittiwakes in the Aleutian Islands. The population fluctuations, but for the most part species has recently been discovered breeding I have not found an indication of a major per- at Buldir and Bogoslof islands (G. Vernon L. W. SOWL

Byrd, personal communication). late March 1972 in Hawkins Cutoff, Prince Is it possible that we have here another William Sound, and again when two birds species which is exhibiting a response to some were noted offshore from the Katmai National unknown long-term perturbation? The sug- Monument on 30 May 1973 (L. W. Sowl, per- gestion that such an event has occurred is sonal observations). faint, but it is there. Do we have in the red- The type specimen of the Aleutian tern and legged and black-legged kittiwakes an a single egg were collected at Kodiak Island example of yet another congener pair that has on 12 June 1868 by Bischoff (Coues 1874). been affected by some perturbation in which Fisher (Gabrielson and Lincoln 1959) collected one was affected positively and the other four more eggs in 1882. The bird was not negatively? Clark (1911) reported small num- found breeding there until Howell (1948) bers of black-legged kittiwakes to go with found a colony of 50 pairs at Bell's Flats in large numbers of red-legged kittiwakes in the 1944. Walker (1923) found them nesting on Near Islands, which is the reverse of the cur- the Situk River, Yakutat, in 1917 and shortly rent situation. thereafter saw them at the Alsek River Flats. He also reported that D. H. Stevenson of the Arctic Tern (Sterna paradisaea) Bureau of Biological Survey had told him that

Gabrielson and Lincoln (1959) attribute to they nested on the Isanotski Islands at the the Arctic tern the most extensive range of end of the Alaska Peninsula. This latter re- any Alaskan water bird. It is found in suitable port was the only one from the Aleutian Is- habitat everywhere north of Tracy Arm in land chain for many years. Isleib and Kessel Southeastern Alaska. Murie (1959) stated (1973) considered it an uncommon local in Isleib that he found it nesting at suitable sites breeder the northern Gulf of Alaska. estimated its everjnvhere he went. Isleib and Kessel (1973) population at a few himdred pairs the Delta in and considered it to be an abundant breeder in on Copper River May 1973 Prince William Sound and along the northern 300-500 birds in June 1970. He also reported Gulf Coast. that they appeared more or less regularly near The Arctic tern was observed in FWS aerial Controller Bay and off the Situk River. surveys in Prince William Sound, and surveys In recent years Aleutian terns have been in July and August 1972 provided an estimate seen with increasing frequency in many places in of 45,000 terns in the Sound (Isleib and Kessel western Alaska and the Aleutian Islands. 1973). On the other hand, tern colonies were This is probably partly due to the increasing located only rarely in the FWS colony surveys level of field work. At Amchitka Island the several colonies that in re- before 1975. This is, however, a reflection of have been found the equipment and methods used and not of cent years are almost certainly exhibiting a the abundance of terns. response to the removal of fox from the island. From the fragmentary data available, it is not possible to detect changes in Arctic tern Although there is no way of determining status at the present time. We have to assume what the past status of the Aleutian tern has that the widespread introduction of fox had at been in the Gulf of Alaska area, it has been least local impact. Although this tern uses a there in small numbers since it was first dis- wide variety of nesting sites, it tends to nest covered on Kodiak. It has probably not been on flat sites where access by mammalian abundant at any time and may have suffered predators is easy. a long-term decline brought about by the introduction of fox.

Aleutian Tern {Sterna aleutica) Murre (Uria aalge) No Aleutian tern colonies were discovered Common in the Gulf of Alaska area during FWS colony The common murre is resident in the north- surveys in the early 1970's. This is again a re- ern and western Gulf of Alaska from Pinnacle flection of the fact that surveys were not de- Rock, Kayak Island, westward. East of Cook signed to locate tern colonies. Aleutian terns Inlet colonies are located at Wingham Island, were encountered at least twice, once during the Martin Islands, Middleton Island, Por- NESTING SEABIRDS OF THE GULF OF ALASKA 61

poise Rock in Hinchinbrook Entrance, Bar- Why does this difference exist? There are two well Island/Cape Resurrection, the Chiswell possible answers: either the number of colo- Islands, the Barren Islands, and Chisik nies has increased, or the coverage of colony Island. locations has improved. The latter case, at For some reason, the islands of the Kodiak- least, is established. I must confess to being Afognak Archipelago do not host any known puzzled by the way Gabrielson was able to major murre colonies. There is also a rather move about close to what are now known to be large gap between the Chisik Island colony sizeable colonies without seeing them, those and the next major colony at Oil Creek west of in the Barren Islands and the Shumagin Is- Puale Bay. Directly west of Oil Creek is an- lands in particular. Perhaps this represents other colony at Cape Unalishagvak. Both of the vague outlines of yet another population these latter colonies are Class V and they are change. the first colonies of this size to be encountered The center of abundance for murre distribu- in the Gulf of Alaska. West of these colonies tion in the Gulf of Alaska today is from Paule the next large colony is at Atkulik Island. To Bay west to eastern Shumagin Islands. The the south, midway between the last-named Semidi Islands are the heartland of this area colonies, lies the major composite murre of maximum abundance. We have no defini- colony in the Semidi Islands. These sites tive data on species composition of these colo- make up the only Class VI colony in the Gulf nies. Common murres undoubtedly dominate of Alaska. Westward, the next major colony, in most of the colonies; the only ones where we a Class V, is at Spitz Island south of Mitro- know of a sizeable thick-billed murre compo- fania Island. In the Shumagin Islands one nent are in the Shumagin Islands. Class V colony is at Karpa Island, and lesser Thick-billed Murre (Una lomvia) colonies with large murre components are found at the Haystacks, Castle Rock, and Thick-billed murre population information Bird Island. Only minor murre colonies are cannot be separated from that of the common found between the Shumagin Islands and the murre on the basis of existing data. A direct end of the Alaska Peninsula. assessment of present-day status is not pos- Gabrielson and Lincoln (1959) were aware sible. After reviewing what we know about only of the colonies at Cape Resurrection their distribution, I suggest a way to examine (which Gabrielson considered to be large), at the question indirectly. the Chiswell Islands, and at Chisik Island for The thick-billed murre is found in colonies the area from Cook Inlet east. Gabrielson with the common murre from Middleton Is- visited the Barren Islands on 13 June 1940 land westward; Rausch (1958) noted about and apparently did not notice the present 400 murres at Middleton Island and observed murre colonies, both Class IV, at East Amu- that the thick-billed murre outnumbered the tuli (an island which he visited) and Nord common murre by several times. Isleib and Island. Sowl (FWS, unpublished data) saw a thick- Gabrielson (Gabrielson and Lincoln 1959) billed murre mixed with common murres at found a few small colonies at Kodiak, mostly Porpoise Rock in July 1972. Isleib and Kessel on small offshore islands. Gabrielson found (1973) expressed the opinion that small num- common murres to be abundant in the Semidi bers of thick-billed murres will be found in Islands and stated that there were no notable most common murre colonies in the northern colonies in the Shumagins, although on his re- Gulf of Alaska when it is possible to survey turn to the Shumagins in 1949 he did find a these colonies in detail. Karpa Island had a fairly large colony at the Haystacks. That size significant component of thick-billed murres description would fit the colony that is there in June 1973, and they constituted 40% of the now. He obviously did not see the other colo- colony at the Haystacks (L. W. Sowl, unpub- nies. Rausch (1958) reported murres from lished data). Middleton Island. Bent (1963) reported that many thick-billed There is quite a difference between the dis- murre eggs have been taken by collectors at tribution of murres as we know it today and Round Island in the Shumagin Islands. Dall the way Gabrielson and Lincoln pictured it. and Bannister (1869) reported a thick-billed 62 L. W. SOWL murre that was taken at Kodiak in 1867. nesting ledges later than the common murre The Gulf of Alaska is at the periphery of the and had to take the sites that were left. Tuck breeding range of the thick-billed murre. (1960) reported data from the western Atlan- While it probably occurs in mixed colonies tic showing that thick-billed murres arrive with the common murre throughout this area, later than common murres. On the other the thick-billed murre is much less abundant. hand, Belopol'skii (1961) reported data show- Occasionally in the Gulf of Alaska, a colony ing that the two species arrive on breeding will be occupied predominantly by the thick- colonies in East Murman simultaneously. At billed murre. Gabrielson and Lincoln (1959) Cape Thompson, Swartz (1966) found that noted that the thick-billed murre outnum- thick-billed murres arrived about a week be- bered the common murre in many colonies in fore common murres. The date of arrival, the Aleutians and that it became progres- while perhaps a contributing factor, is prob- sively more common at higher latitudes. ably not decisive. Interspecific competition of We have almost no data relative to the another sort is indicated. species composition of murre colonies in the In mixed murre colonies where there are Gulf of Alaska. Until we do it will not be pos- large numbers of common murres, this species sible to fully understand the population occupies the choice nesting sites. Thick-billed status of the thick-billed murre. It appears murres are usually left with the narrower that changes in the species composition of ledges while the common murres occupy the murre colonies in the Bering Sea may be an in- longer, broader ledges (Belopol'skii 1961). The dicator of perturbation. The data for the Gulf broader ledges have lower chick and egg mor- of Alaska are still too fragmentary to provide taUty (Spring 1971). Spring also noted that any indication of whether or not the same in- thick-billed murres are excluded from the cen- dicator would work there. Close monitoring of ters of mixed colonies. Johnson (1938) found the Shumagin Islands colonies over a number that this contributes to higher losses of eggs of years might produce the answer. to predators and to the loss of other social Earlier in this paper I noted the dramatic benefits of occupying the colony center (John- changes in species composition of murre colo- son 1941). nies on Walrus Island. Gabrielson and Lincoln Kozlova (1961) said that during the occupa- (1959) also commented on this well-docu- tion of a colony there is a sharp competitive mented and anything but static situation. In- struggle between the two species. In the end vestigators who visited this island during thick-billed murres are pushed out to the pe- 1976 reported seeing no murres on the island riphery of the colonies or left with narrow and only small numbers on offshore rocks. ledges or other equally unfavorable sites. James Bartonek (personal communication) Spring (1971) studied the functional anatomy said that this situation has prevailed for of both species and concluded that the com- several years. mon murre is more successful in these encoun- There is an indication that a similar popula- ters because it has a more upright gait and tion fluctuation and change in species com- greater agility than the thick-billed murre. position of murre colonies have also occurred It follows that in a portion of their respec- on St. Matthew Island. Bent (1963) found tive ranges, where the two species overlap and mostly common murres and few thick-billed where there is an equal chance that either murres at St. Matthew. Hanna (1916) saw common murres or thick-billed murres will only thick-billed murres. Later, Gabrielson dominate a given colony, the common murre (1941) found this to be true in 1940. dominates. I conclude from this that where Dramatic fluctuation in murre populations there are dramatic changes in species com- may be common and, at least in some cases, position of murre colonies, such as at Walrus the two species may be affected differently. Island, it is probably because the common Perhaps this phenomenon has potential for murre has been greatly reduced in numbers at providing us with an indicator of some natu- the colony. ral perturbations. Spring (1971) concluded that the common Peterson and Fisher (1955) expressed the murre is well adapted to pursuit and capture opinion that thick-billed murres arrived at the of pelagic fishes and that the thick-billed NESTING SEABIRDS OF THE GULF OF ALASKA 63

murre is better adapted for deep diving and mot has been greatly affected by any major the capture of benthic fishes and pelagic and perturbation. Because of its choice of nesting benthic invertebrates. Having greater lati- habitat, it is probably subject to the attack of tude for food selection, the thick-billed murre only one egg predator, the rat. Because of its would have a greater tolerance for ecological loose social structure and the way it selects perturbations affecting the available food nesting sites, eggs and young do not sustain supply. The common murre has an advantage loss from panic flights. Its dispersed distribu- when pelagic fishes are available but cannot tion should insure that man-made impacts switch to the other foods as readily as can the such as oil spills will have limited impact. thick-billed murre. The low density of pelagic The population levels of the pigeon guille- fishes in high arctic areas probably also ac- mot are probably relatively very stable. The counts for the greater success of the thick- widespread introduction of the rat to most of billed murre at higher latitudes relative to its nesting range undoubtedly had impact, common murres. but this impact has gone undocumented. It Belopol'skii (1961) presented data from would be interesting to follow the response of East Murman which indicates that the com- guillemot populations on islands where rats mon murre restricts its diet almost entirely to had been totally removed, if that ever be- a small number of fish species. Swartz (1966) comes more than a dream. found strong indications that there were significant differences in the food preferences of Marbeled Murrelet (Brachyramphus the two species of murres. Thick-billed murres marmoratus) made much greater use of invertebrates. The marbled murrelet apparently breeds Bedard (1976) asserted that it is well known throughout most of the northern and western is that the common murre quite partial to zoo- Gulf of Alaska. This apparently is a necessary plankton. So again the issue is not clear-cut. condition because to date, at least in this part The situation is, of course, much more com- of Alaska, we can only guess where and under plex than I have portrayed it. Nonetheless, I what conditions this murrelet breeds. think that it offers potential for use as a tool In some relatively sheltered waters like in assessing population change and perturba- Prince William Sound, where marbled murre- tions in the food supply which should be lefcs were estimated to number about 250,000 studied quite closely. in 1972 (Isleib and Kessel 1973), they are the most abundant seabirds. We know from Pigeon Guillemot {Cepphus columba) Dixon (1908) and Grinnell (1910) that this has Gabrielson and Lincoln (1959) noted that been so in Prince William Sound since the be- the pigeon guillemot was one of the most ginning of the century. We know also that the regularly observed birds in Alaskan waters. It type specimens came from there as well is found everjrwhere throughout the northern (Stresemann 1949), which is not necessarily and western Gulf of Alaska area, with only a an indication of abundance but is suggestive few understandable and relatively small of their abundance relative to species not blanks, such as in the silty waters of Upper collected. Cook Inlet. Because it obviously lacks the Gabrielson (Gabrielson and Lincoln 1959) breeding murres' need for close contact with found marbled murrelets common near Yaku- its nearest neighbors, it is able to exploit the tat, in Prince William Sound, in Resurrection available nesting habitat to the fullest. It Bay, and at Kodiak, and reported seeing them seems that literally every bit of suitable nest- at the Chiswell Islands and at Chignik and ing habitat is normally occupied. Pavlof Bay on the Alaska Peninsula. Caha- Because of the dispersed way in which it lane (1943, 1944) found them to be common in breeds and because it does much of its feeding Kupreanof Strait, and along the Alaska in the onshore zone (which is hazardous for Peninsula north of Katmai Bay. Murie (1959) boats) the pigeon guillemot is an almost im- found them all along the Alaska Peninsula. possible species to inventory by standard My own field notes from 1973 indicate that methods. the only place where they were common along There is no evidence that the pigeon guille- the Alaska Peninsula was at Wide Bay. 64 L. W. SOWL

We can sample marbled murrelet numbers the same relative abundance and distribution by using standard transect methodology; that it did at the beginning of the century. however, I have some very serious reserva- tions about our ability to convert these data Kittlitz's Murrelet (Brachyramphus into population estimate. This is un- a not an brevirostris) usual assessment for Alaskan seabirds in The Kittlitz's murrelet is not as abundant general, but I think it is particularly apropos the to this species. as marbled murrelet, but locally it is sometimes found in large numbers. surveys We are still able only to guess at where the FWS marbled murrelet nests and we have not a clue conducted during July-August 1972 provide as to what sort of nesting strategy they pur- an estimate of 57,000 murrelets of this species in Prince William Sound. Almost a fifth of sue. I am not prepared to accept, on the basis these were concentrated in Inlet of one North American record (Binford et al. Unakwik above Reef. more interesting, 1975), that tree nesting is its habit through- Unakwik Even about of these birds were concentrated out its range. What has been proved is that 2,500 in loose flock. the marbled murrelet nests in trees and not, one In addition to Unakwik Inlet, KittUtz's as these authors would have us believe, that it murrelets concentrate in College Fjord in does not nest on the ground. It has become Prince William Sound and in the waters front- rather fashionable to ignore the Chichagof Is- ing the Bering-Malaspina icefields (Isleib and land record (a ground nest), but it has not as are in these been discredited. The color of the Chichagof Kessel 1973). Common they waters, this species is to even egg differs from that of the Big Basin egg, but supposed be does agree with the one taken from an oviduct more abundant at Glacier Bay. The common feature of these waters is the amount of ice by Cantwell (Gabrielson and Lincoln 1959). that can be found below their tributary My own experience leads me to believe that glaciers. tree nesting, if it occurs, is not the common The Kittlitz's murrelet is apparently dis- habit of marbled murrelets nesting in the tributed Peters- Prince William Sound region. from LeConte Bay, east of After many hours of observing marbled burg, Alaska, north to Point Barrow and west across the Aleutians to Attu, where Murie col- murrelets over a period of several years, I am lected pair (Gabrielson Lincoln I intrigued by a number of things. These birds, a and 1959). once flushed of as often as not, appear to be clustered in a murrelet from an area tread riser the of the "pairs" as they feed. This occurs even at what and topography near top should be the height of the breeding season. highest point on Kiska Island in heavy cloud cover, and although I could not see this bird On several occasions I have noted a very pronounced evening flight of these birds from well, I thought it to be of this species. From the range description in Gabrielson gathering areas on the water up into the sur- and rounding mountains at sunset. This has Lincoln (1959) and Udvardy's (1963) range map, it is apparent that the distribution of moved me to wonder if their nesting strategy this species is rather patchy, but I suspect includes incubating at night but less than full- time attendance on days when the eggs can be that for the more mountainous part of its range this is more apparent than accurate. warmed by the sun. We know that periodic The record is too fragmentary to allow an as- egg-neglect is an aspect of storm-petrel be- sessment of any change in status during the havior (Pefaur 1974). Is this behavior also historical period. possible on a more regular basis in an alcid? If so, it would certainly help explain why nests Ancient Murrelet {Synthliboramphus are hard to find. antiquus) It is apparent that more needs to be known about the population dynamics and life his- Chase Littlejohn (Bendire 1895) spent the tory of the marbled murrelet before we can spring and summer of 1894 collecting eggs on make a proper estimate of its abundance. In islands south of the Alaska Peninsula. He has spite of the fragmentary record, I conclude left us a detailed record of what he saw but

that the marbled murrelet probably enjoys not where he saw it. Bent (1963) stated flatly NESTING SEABIRDS OF THE GULF OF ALASKA 65

that the site of his collecting was Sanak Is- 1928. Gabrielson collected one bird at Cor- land and this has common acceptance. Several dova in September 1941 and another at the things in his account point to a site which was Chiswell Islands in July 1945 (Gabrielson and a small island with several peers close by, but Lincoln 1959). He saw numerous flocks in the this could not have been Sanak. It could have Gulf of Alaska on 30 July of an unnamed year. been an island in the Sanak Island group or it In 1943, he would have been near Cape could equally well have been somewhere in the Spencer on that date. In 1945 he would have Sandman Reefs. Unfortunately, because of been near the Chiswell Islands. In either case, this the record is clouded. There has never he was probably somewhere in Blying Sound. been anything approaching a survey of the The ancient murrelet is relatively uncom- southern half of the Sandman Reefs. We do mon but regularly observed in the inshore not know what breeding colonies are there. waters along the outer coasts of the islands At any rate, Littlejohn told of the large fronting Prince William Sound. FWS surveys numbers of Leach's storm-petrels, fork-tailed in July-August 1972 provided an estimate of storm-petrels, auklets (of which only Cassin's almost 1,000 birds, mostly in nonbreeding is specifically identified), and ancient murre- plumage, along the outer coast of Prince lets which occupied a large number of small is- William Sound (Isleib and Kessel 1973). Small lands. He could not calculate the number of numbers were found feeding close to the breeding murrelets on his small island, the Wooded Islands on 24 July (my personal ob- size of which I interpret to have been of the servation). Rausch (1958) saw a few off same order of magnitude as two others which Middleton Island in 1956. Isleib (Isleib and he estimated were about 2 acres. He does say Kessel 1973) saw 400-500 widely distributed that the murrelets must have numbered at the mouth of Yakutat Bay in July and Au- several thousand and could, if left alone by gust 1968. The only large numbers of ancient the Aleuts, have quickly grown too numerous murrelets encountered on the FWS survey of for the island to accommodate. the Alaskan Peninsula in 1973 were in the Shumagin Islands. They were very common in Murie (1959) made a brief visit to Sanak in East Nagai Strait on 9 June and more than 1937 and learned that there were no longer half of the 1,300 seabirds per square nautical any large colonies of seabirds. He attributes mile encountered between Little Koniuji and this to exploitation of the fisheries and to the Chernabura Islands on 11 June were ancient fox-farming industry. Littlejohn told of the murrelets. At Nagai Island an estimated repeated visits of Aleuts to his small islands, 5,000 ancient murrelets were observed in the where they took hundreds of birds each time west bay at Pirate Shake, and later (on and all of the eggs they could find. This kind 19 June) several were observed in the vicinity of activity could not help but disrupt the of Midun Island (FWS, Anchorage, Alaska, breeding on these islands. unpublished data). Littlejohn 's description of the ancient On the basis of the observations recounted murrelet's nest leaves little doubt that the above, I have to conclude that ancient murre- birds could be reached by fox or rats with lets are fairly regularly, if patchily, disease. The birds showed no particular care in tributed throughout the northern and western selecting a nest site and often worked their Gulf of Alaska. I do not believe that the void way back no more than about a meter into the in their range shown for the northern Gulf of dead vegetative cover from preceding years, Alaska by Udvardy (1963) is correct. Several where they scratched out a shallow nest. colonies are there, awaiting discovery. There are few records of the ancient murre- Ancient murrelets are not abundant in the let from the northern and western Gulf of Gulf of Alaska but they are certainly more Alaska. Friedmann (1935) reported the collec- numerous than we have been able to prove. It tion of a series of eggs in 1884 on Kodiak Is- is not possible to tell from the existing data land. Chase Littlejohn (Bendire 1895) col- whether they were once more abundant than lected eggs from somewhere in the Sanak they are now. I suspect, on the basis of the Group in 1894. In 1908 Dixon (Grinnell 1910) Sanak Island experience, that we can con- saw a bird in Port Nellie Juan. Several were clude that this species has been reduced in seen by Jaques (1930) near Belkofski in May number by various of man's activities. 66 L. W. SOWL

Cassin's Auklet (Ptychoramphus aleuticus) the Alaskan auklets. They also considered the Aleutian Islands to be its principal nesting Cassin's auklet is a very uncommon bird in grounds. There are old the northern Gulf of Alaska. In the western records of breeding parakeet auklets from Kodiak (Friedmann Gulf it is more common, particularly from the 1935) and Little Koniuji Shumagins west. (Bean 1882). Grinnell (1910) reported two that were seen on This auklet apparently once bred in great Green Island, Prince WilUam Sound, and several numbers on islands in or near the Sanak more that were seen near Knight Island. Group where Chase Littlejohn (Bendire 1895) Murie (1959) did not see any parakeet auk- found them to be twice as numerous as the an- lets near Kodiak and Afognak islands which cient murrelets. Murie (1959) did not find he considered to be the eastern part of their them there. range. He did not think they were Littlejohn began encountering Cassin's abundant anywhere along the Alaska Peninsula. auklets at sea some 290 km southeast of He found a few near Sutwik Island in Unga, Shumagin Islands. Murie (1959) en- May 1936 and then noted that they were fairly common countered them near the Shumagins in May near the Shumagins in 1937. During the FWS 1973 reconnaissance May 1937. survey of the Alaska Peninsula, these auklets Gabrielson found this species to be quite numerous the were not encountered (or at least not identi- on north side of Chowiet Island in the Semidi Islands in fied) until we reached the vicinity of Unga 1945 (Gabrielson and Lincoln Strait where we saw a few in mixed flocks 1959). He also saw numerous indi- with other murrelets and auklets. They were viduals in Marmot Strait and saw one in the Chiswell Islands during the most numerous in East Nagai Strait. We en- same year. David countered them only twice in a situation Roseneau (Isleib and Kessel 1973) found hun- which indicated they might be breeding—on dreds close to East Amatuli Island in the Bar- ren Islands Hall and Herendeen islands on the north end in 1965. of Little Koniuji Island. During FWS colony surveys, parakeet auklets have in Murie (1959) considered Cassin's auklet to been found close proximity to six seabird colonies be no longer common west of Kodiak. In in Prince WiUiam Sound. During the Gabrielson's many voyages through the July-August 1972 surveys, they were estimated to northern and western Gulf of Alaska he en- number about 3,000 in the Sound. They have also countered them only twice, once off Cape been found closely as- Spencer and once in the Chiswell Islands. sociated with Chisik Island (David Snarski, Thoresen (1964) commented that through- personal communication), the Chiswell Is- lands, out the northern part of its range the Cassin's Nord and Sud islands in the Barrens, Sea Island, auklet has become gradually less frequent. Al- Otter and Central and Long islands along the Alaska Peninsula. though there are no data to dispute this, I be- They were most in lieve, as do Isleib and Kessel (1973), that they numerous the Shumagin Islands, are more numerous than observations would where they were found near Castle Rock, Hall indicate, and I would apply this to the entire (9,000), Herendeen (3,000), Atkins (more than area. There are certainly colonies remaining in 5,000), and Little Koniuju islands. They were the Shumagin Islands, and quite probably again encountered south and west of Cold Bay along the south coast of the Kenai Peninsula. at High, Fawn, Let, Amagat, Umga, and Patton islands. When it is possible to fully explore the Sand- Many of these islands are in the north half of man Reefs there is a good probability that the Sandman Reefs, the only they will be found there. portion where any attempt has been made to survey seabird We can only guess at the reasons for their colonies. The parakeet auklet decline. Bendire (1895) and Murie (1959) have may not be abundant described some contributing factors. anywhere in the Gulf of Alaska but, based on the numbers of places it has been seen in recent years, its population appears to be well Parakeet Auklet {Cyclorrhyncus psittacula) dispersed and probably doing very well. This Gabrielson and Lincoln (1959) described the auklet is most abundant from the Shumagin parakeet auklet as the least colonial of any of Islands westward. It is almost certainly more NESTING SEABIRDS OF THE GULF OF ALASKA 67

numerous than has been thought. Its habits have been estimated to number as high as 36 are secretive enough so that it could easily million (Peterson and Fisher 1955). The num- escape notice. bers there today do not even approach this Because the parakeet auklet nests predomi- level and we have no way of knowing how nantly under boulders, it probably was not abundant they were when Townsend visited much affected by fox. Rats would certainly the Pribilofs, but I think it is safe to say that have reduced its numbers wherever these they probably numbered in the millions. There were introduced into its breeding habitat. We are probably more crested auklets than we ob- have no data to tell us whether there may served on Little Koniuji, but there is certainly have been population fluctuations in the past, no longer anything approaching millions of but there undoubtedly were at least minor birds. Properly pronounced, Koniuji is the ones locally after rats were introduced. Aleut name for the crested auklet, so we can assume that the original inhabitants were im- {Aethia Crested Auklet pygmaea) pressed by its numbers. Udvardy (1963) shows the breeding range of During the 1973 FWS survey we did not see the crested auklet as extending from southern crested auklets at either Simeonof or Bird is- Kodiak Island westward. Within the northern lands. On the overgrazed and cattle-trampled and western Gulf of Alaska, it is certainly Simeonof it does not seem possible that any most abundant in the eastern Shumagin could still exist. Islands. I suspect that a cattleman's greed has been Isleib saw this auklet in Prince WilUam the undoing of any crested auklets that may Sound 3 times during the winter of 1972-73. have nested on Simeonof Island. This would These are the only records he was aware of for not account for the loss of any colonies that that area (Isleib and Kessel 1973). David may have been on Bird Island, but the decay- Roseneau (Isleib and Kessel 1973) saw several ing fox-trapper's cabin on that island unin Amatuli Cove, Barren Islands, in June doubtedly tells the story. Churnabura, with 1965. I observed one in the vicinity of Cape its feral cattle, presents much the same prob- Spencer in August 1973. lem as Simeonof. As for Little Koniuji, have Friedmann (1935) listed the crested auklet horned puffins been partly responsible for the as a breeding bird at Kodiak, but considered it decrease in crested auklets? The puffin colony to be much more abundant as a wintering at the south end of Little Koniuji must be bird. Townsend (1913) has provided us with a exactly where Townsend's millions of crested vivid description of the myriads of crested auklets once nested. auklets he encountered at Yukon Harbor, Little Koniuji Island. Gabrielson and Lincoln Least Auklet (Aethia pusilla) (1959) noted large numbers of crested auklet No least auklets were encountered in FWS around Simeonof and Bird islands in the Shu- surveys in the Gulf of Alaska in the early magin Islands in 1946 and stated that the 1970's. Udvardy (1963) shows their breeding Yukon Harbor colony was still thriving. range as starting well west in the Aleutians. Crested auklets were not encountered on Gabrielson and Lincoln (1959) give the east- the 1973 FWS reconnaissance survey until we ern limit of their breeding range as the Shu- reached the Shumagin Islands. They were magin Islands. Bent (1963) listed their breed- abundant only at the southeastern end of ing range as extending east to Kodiak Island, Little Koniuji, where we encountered perhaps and Friedmann (1935) knew of only a few 10,000 in Yukon Harbor and more than 50,000 specimens taken in the winter from Kodiak. in a small cove directly south of Yukon Har- Perhaps least auklets nested somewhere in bor on the opposite side of the island. As the western Gulf of Alaska, and they may numerous as they were, they did not match still, but at the moment we have no evidence Townsend's myriads or even come close to his to prove that they do. assessment that they "were here more Rhinoceros Auklet (Cerorhinca monocerata) numerous than the 'choochkies' at St. George." St. George Island in the Pribilofs is Udvardy (1963) would have us believe that I famous for its least auklets which, in the past. the rhinoceros auklet did not nest between 68 L. W. SOWL southeastern Alaska and the southern Kurile surveys in 1973, I estimated that the fre- Islands. Bent (19636), on the other hand, lists quency with which these birds were seen on their breeding range as extending from Wash- the water was about half that of the tufted ington to Agattu. Clark (1910) noted this puffin. They have been recorded in so many species in small numbers at Atka and Agattu. places that there is nothing to be gained by a Because of the lack of proof, Udvardy prob- reiteration of the record in the literature. ably had no options. I beUeve that Bent was The horned puffins reach their greatest den- probably closer to describing their original sity in the Gulf of Alaska west of Kodiak Is- range. I base this assumption on recent obser- land, Murie (1959) estimated that the colony vations and on the additional fragments of in- at Amagat Island, Morzhovi Bay, contained formation reported by Gabrielson and Lincoln 15,000 birds, one of the largest he had seen. It (1959). Murie (1959) failed to find this species contained at least 50,000 in 1973. Even at anywhere in the Aleutians, but his primary that, it was no match for the colony on Little reason for being there, the fox-farming indus- Koniuji Island with its minimum 140,000 try, may have had a lot to do with his not horned puffins. Other colonies with large being able to find any. horned puffin components were at High Is- The FWS surveys in Prince William Sound land (40,000), Castle Rock (20,000), Mitrofani in July-August 1972 located small numbers of Island (35,000), and Sosbee Bay (15,000). rhinoceros auklets in breeding plumage at the Earlier in this paper, I commented at length Wooded Islands and at Stoney Island and on the great and often rapid fluctuations in Channel Island in Montague Strait. These populations of tufted puffins. The same phe- birds gave every impression of being local nomenon affects horned puffins. In 1975 there breeders. David Roseneau (Isleib and Kessel were relatively small numbers of horned 1973) encountered two at the Barren Islands puffins at Little Koniuji where they had in June 1965. Isleib and Kessel (1973) list a flourished 2 years earlier (James Bartonek, few other records from this area. personal communication). Because they are My own experience leads me to believe that apparently subject to erratically oscillating there is a large colony somewhere on Afognak populations, it is hard to tell how they have Island, probably on or near Tonki Cape. On 30 fared over the years.

May 1973 I noted a lone bird north of Afog- nak Island. Later, on 8 and 9 August, I saw Tufted Puffin (Lunda cirrhata) several in the same area. On 13 August in The tufted puffin, as previously indicated, Strait I observed number of rhi- Marmot a is also a bird with widely fluctuating popula- of noceros auklets, either singly or in groups tions. Until we develop an understanding of up to 12. Some of these had small fish in their their population dynamics and can under- beaks. As they flushed, they all flew off stand the underlying cause of these fluctua- toward Tonki Cape. This observation was tions it will not be possible to assess trends in made just at last light, and I believe that their populations or understand the implica- there were many others about that could not tions of such trends. be seen in the dying light. We did not encoun- Tufted puffins are abundant throughout the ter this species along the Alaska Peninsula Gulf of Alaska. Small colonies can be located during the FWS survey in 1973 until we almost an5rwhere. Along the Alaska Peninsula reached the end. There I had one quick there are a number of colonies with an esti- glimpse of I certain rhi- what was was a mated breeding population in 1973 of more noceros auklet at Island. Amagat than 15,000 birds. These are: Ashiiak Island (20,000), Central Island (90,000), the Brother Horned Puffin (Fratercula comiculata) Islands (45,000), The Haystacks (19,000), The horned puffin is one of the most abun- Castle Rock (85,000), Bird Island (none, but dant breeding birds in the Gulf of Alaska, may contain 500,000-1,000,000 at times). There are only a few really large colonies but Peninsula Islands (35,000), the Twins these birds breed just about anj^where there is (18,000), Amagat Island (40,000), and Umga a cliff (even a low one) with suitable fractures Island (22,000). These colonies correspond to and crevices. During the Alaska Peninsula the area where colonies were Usted for the NESTING SEABIRDS OF THE GULF OF ALASKA 69

horned puffin. made his voyage of discovery. There are, Tufted puffin populations respond readily nonetheless, considerable numbers of seabirds to some undetermined short-term perturba- breeding along the coasts of these waters. tions. This is clearly demonstrated by their Some species show signs of recovery from rapid population fluctuations. Because of past insults by man. With enlightened man- their numbers and because of the apparent agement there is still time to preserve the rapidity with which their numbers rebound, it vast natural heritage that they represent and, is not so apparent that they have been af- in many cases, to improve their status. fected by long-term perturbations, as so many In attempting to address a complicated other seabirds apparently have. subject in short space and a relatively narrow There is much unused or underused nesting frame of reference, I have certainly erred a habitat suitable for this species. In some number of times. I would like to see the cases there are very strong clues pointing to wealth of new data that will be derived from why this habitat is vacant. On many islands current work applied to this concept. An un- along the Alaska Peninsula, which have very derstanding of past population fluctuations good-looking tufted puffin nesting habitat and the underlying perturbations that they and no puffins, there are visible signs of the reflect is essential for managers faced with presence of fox— either fox trails or aban- the problem of making good decisions on doned trappers' cabins. I also suspect that the measures to mitigate the potential adverse brown bear (Ursa arctos) is another possible impact of development. contributing factor to population declines of burrow nesters along this coast. I have seen brown bears swimming from island to island References on foraging expeditions. George J. Divoky

(personal communication) has found brown American Ornithologists' Union. 1931. Check-list of bears visiting Ugaiushak Island, which is North American birds, 4th ed. American Orni- 13 km from shore. There are other islands be- thologists' Union, Baltimore, Md. 530 pp. tween Ugaiushak and the mainland but the American Ornithologists' Union. 1957. Check-list of North American birds, 5th ed. American Orni- shortest route from shore would require one thologists' Union, Baltimore, Md. 691 pp. swim of 7 km. The motivation must be strong. Amundsen, C. C. 1972. Plant ecology of Amchitka Tufted puffins may shift from colony to Island. Amchitka bio-environmental program. colony. This could be an explanation for ap- Final Report, Battelle Columbus Lab., Columbus, Ohio. 27 pp. parent local population fluctuation, but if so, Bailey, A. M. 1948. Birds of arctic Alaska. Colo. I puzzled the apparent tenacity with am by Mus. Nat. Hist. Pop. Publ. 8. 316 pp. which puffins cling to some sites. Their con- Baird, S. F. 1869. On additions to the bird fauna of stant occupancy of sites where the vegetative North America, made by the scientific corps of the Russo-American Telegraph Expedition. mat is breakaway tundra (Amundsen 1972) or Trans. Chic. Acad. Sci. 1(2):31 1-325. is underlain by sand results in the destruction Beaglehole, J. C. 1974. The life of Captain James of these sites. Tufted puffins often cling to Cook. Stanford Univ. Press, Stanford, Calif. them in spite of the fact that they have been 734 pp. reduced to "slums." Bean, T. H. 1882. Notes on birds collected during the summer of 1880 in Alaska and Siberia. Proc. My conclusion is that in spite of their large U. S. Natl. Mus. 5:144-173. it numbers appears that tufted puffin popula- Bedard, J. 1976. Coexistence, coevolution and con- tions in the Gulf of Alaska probably have vergent evolution in seabirds: a comment. Ecol- been reduced to a level below that of their un- ogy 57(1):177-184. Belopol'skii, L. O. 1961. Ecology of sea colony birds disturbed state. of the Barents Sea. (Transl. from Russian.) Israel Program for Scientific Translations, Jerusalem. 346 pp. Conclusions Bendire, C. 1895. Notes on the ancient murrelet (Synthliboramphus antiquus) by Chase Little- john with annotations. Auk 12(3):270-278. Seabird numbers in the Gulf of Alaska are Bent, A. C. 1963. Life histories of North American not static. Generally, they are probably much diving birds. Dover Publications, Inc., New York. less abundant than they were when Bering 239 pp. 70 L. W. SOWL

Bent, A. C. 1964. Life histories of North American Hanna, G. D. 1916. Records of birds new to the petrels, pelicans and their allies. Dover Publica- Pribilof Islands, including two new to North tions, Inc., New York. 335 pp. America. Auk 33:400-403. Binford, L. C, B. G. ElUot, and S. W. Singer. 1975. Howell, J. C. 1948. Observations on certain birds of Discovery of the nest and downy young of the the region of Kodiak Island. Auk 65:352-358. marbled murrelet. Wilson Bull. 87(3):303-319. Hrdlicka, A. 1945. The Aleutian and Commander Bowles, J. H. 1908. Tapeworm epidemic among Islands and their inhabitants. Wistar Institute Washington seabirds. Condor 11:33. Anatomical Biology, Philadelphia. 630 pp. Cahalane, V. H. 1943. Notes on the Kodiak-Afog- Isleib, M. E., and B. Kessel. 1973. Birds of the nak Island group. Auk 60(4):536-541. North Gulf Coast-Prince William Sound region, Cahalane, V. H. 1944. Birds of the Katmai region, Alaska. Biol. Pap. Univ. Alaska No. 14. 148 pp. Alaska. 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Israel Program for Scientific Translations, Jeru- Nichols, J. T. 1927. Tubinares of the Northwest salem. 553 pp. Coast. Auk 44(3):326-328. Dixon, J. S. 1908. Field notes from Alaska. Condor Orth, D. J. 1967. Dictionary of Alaska place names. 10:139-143. Geol. Surv. Prof. Pap. 567. 1084 pp. East, B. 1943. Seabird cities of the Aleutians. Nat. Palmer, R. S. 1962. Handbook of North American Hist. 51:64-71. Birds. Vol. I. Yale University Press, New Haven, Fisher, J., and R. M. Lockley. 1954. Seabirds. Conn. 567 pp. William CoUins and Sons, London. 320 pp. Patten, S. M., Jr. 1976. Sympatry and interbreed- Friedmann, H. 1934. Bird bones from Eskimo ruins ing of herring and glaucous-winged gulls in south- on St. Lawrence Island. J. Wash. Acad. Sci. ern Alaska. Pac. Seabird Group Bull. 3(l):25-26. 24:83-96. Pefaur, J. E. 1974. Egg-neglect in the Wilson's Friedmann, H. 1935. The birds of Kodiak Island, storm petrel. Wilson BuU. 87(l):16-22. Alaska. BuU. Chic. Acad. Sci. 5(3): 13-54. Peterson, R. T., and J. Fisher. 1955. Wild America. Friedmann, H. 1937. Bird bones from archeological Weather Vane Books, New York. 434 pp. sites in Alaska. J. Wash. Acad. Sci. 27:431-438. Rausch, R. L. 1958. The occurrence and distribution Gabrielson, I. N. 1940. America's greatest bird con- of birds on Middleton Island, Alaska. Condor centrations, Part I. Bird Lore 42:497-506. 60:227-242. Gabrielson, I. N. 1941. America's greatest bird con- Schlegel, H. 1862-64. A catalogue of birds in the centrations. Part II. Audubon Mag. 43:15-23. Dresden Museum of Natural History, Leyden. Gabrielson, I. N. 1944. Some Alaskan notes. Auk Dresden Museum of Natural History, 7 Vols. 61:105-130,207-287. Sowl, L. W., and J. C. Bartonek. 1974. Seabirds— Gabrielson, I. N., and F. C. Lincohi. 1959. The birds Alaska's most neglected resource. Trans. N. Am. of Alaska. The Stackpole Company, Harrisburg, Wildl. Natl. Resour. Conf. 39:117-125. Penn. 922 pp. Spring, L. 1971. A comparison of functional and Golder, F. A. 1925. Bering's voyages. Vol. II. morphological adaptions in the common murre American Geographical Society No. 2. 290 pp. {Uria aalge) and thick-billed murre (Una lomvia). Grinnell, J. 1910. Birds of the 1908 Alexander Alas- Condor 73:1-27. kan Expedition with a note on the avifaunal rela- Stejneger, L. 1885. Results of ornithological ex- tionships of the Prince William Sound district. plorations in the Commander Islands and in Univ. Calif. Publ. Zool. 5:361-428. Kamtschatka. Bull. U. S. Natl. Mus. 29:1-382. NESTING SEABIRDS OF THE GULF OF ALASKA 71

Stresemann, E. 1949. Birds collected in the North Pacific Basin biogeography, a symposium. Pac. Pacific area during Captain James Cook's last Sci. Congr. Proc. 10. voyage (1778 and 1779). Ibis 91:244-255. U. S. Bureau of Sport Fisheries and Wildlife. 1973. Swartz, L. G. 1966. Sea-cliff birds. Pages 611-678 in Semidi Islands wilderness report. Semidi Islands, N. J. Wilimovsky and J. N. Wolf, eds. Environ- National Wildlife Refuge. (Unpublished report) ment of the Cape Thomson Region, Alaska. U. S. U. S. Department of Commerce. 1964. United Atomic Energy Commission, Oak Ridge, Tenn. States Coast Pilot, No. 9, Pacific and Arctic Thoresen, A. C. 1964. The breeding behavior of the Coasts, Cape Spencer to the Beaufort Sea. Coast Cassm's auklet. Condor 66:456-476. and Geodetic Survey, Washington, D. C. 330 pp. Townsend, C. H. 1913. The crested auklet. Bird- Lore 15:133-136. Walker, E. P. 1923. Definite breeding record for the Tuck, L. M. 1960. The Murres. Queen's Printer, Aleutian tern in southern Alaska. Condor 25:113- Ottawa. 260 pp. 117. Turner, L. M. 1885. Notes on the birds of the Near Willet, G. 1914. Birds of Sitka and vicinity. South- Islands, Alaska. Auk 2:154-159. eastern Alaska. Condor 16:71-91. Turner, L. M. 1886. Contributions to the natural Willet, G. 1918. Bird notes from Forrester Island, history of Alaska. Part V, Birds. U. S. Army, Sig- Alaska. Condor 20:85. nal Corps, Washington, D. C. Pages 115-196. Williamson, F. S. L., and L. S. Peyton. 1963. Inter- Udvardy, M. D. F. 1963. Zoogeographic study of breeding of glaucous-winged herring gulls in the the Alcidae. Pages 85-111 in J. L. Gressitt, ed. Cook Inlet Region, Alaska. Condor 65:28.

Status and Distribution of Breeding Seabirds of Southeastern Alaska, British Columbia, and Washington

By David A. Manuwal College of Forest Resources University of Washington Seattle, Washington 98195

V and R. Wayne Campbell Provincial Museum Victoria, British Columbia, Canada

Abstract

Current breeding seabird population estimates, nest-site preferences, and population changes are reviewed for southeastern Alaska, British Columbia, and Washington. There are 19 species of seabirds and a minimum of 216,566 pairs breeding in British Columbia and Washington. There are limited data on breeding populations for southeastern Alaska. Species diversity ranges from 17 species in Alaska to 15 species in British Columbia and 14 species in Washing- ton. Eighty percent of all British Columbia seabirds breed on the east coast of Queen Charlotte Islands and the northwest coast of Vancouver Island. The three most numerous species in British Columbia are the fork-tailed storm-petrel, Oceanodroma furcata (31.3%); Cassin's auklet, Ptychoramphus aleuticus (24.6%); and ancient murrelet, Synthliboramphus antiquus (12.5%). In Washington, 74% (43,274 pairs) of the seabird population resides on the Olympic coast; the remaining 26% are in the San Juan Island area. About 54% of this population consists of the common murre {Uria aalge) and rhinoceros auklet (Cerorhinca monocerata). The rhinoceos auklet and glaucous-winged gull (Larus glaucescens) make up 97% of the total seabird population of the San Juan Islands. About 68% of all seabirds on the northeastern Pacific coast are nocturnal, burrow- or rock crevice- nesting species. Currently available population data are inadequate to determine significant changes in population density for most species. Suggested topics for future research are presented.

The purpose of this paper is to discuss the Columbia (Drent and Guiguet 1961). Gabriel- known distribution, habitat, abundance, and son and Lincoln (1959) summarized the avail- status of breeding seabirds of the Alexander able Uterature on Alaskan birds up to about Archipelago in southeastern Alaska, the 1958. Since then, no extensive surveys have been conducted in southeastern Alaska. The Province of British Columbia, Canada, and U. S. Department of the Interior (1972), in its the State of Washington. environmental impact statement for the Even though several studies of the breedmg Trans-Alaska PipeUne, presented additional biology of several seabird species in this area information on the seabirds of other parts of have been pubUshed, there have been few pub- Alaska. In Washington, there are no pub- Ushed surveys of known breeding colonies. In Ushed comprehensive surveys except those of British Columbia the most extensive work Kenyon and Scheffer (1961) and unpubUshed has been done by the British Columbia Pro- surveys by the U. S. Fish and Wildlife Service vincial Museum and the University of British and the University of Washington.

73 74 D. A. MANUWAL AND R. W. CAMPBELL

Table 1. Taxonomic distribution of marine birds breeding along the Pacific Coast of Washing- ton, British Columbia, and southeastern Alaska.

Regions

British Southeastern Total Family Common name Washington Columbia Alaska forms

Hydrobatidae Storm-petrels 2 2 2 2 Phalacrocoracidae Cormorants 3 3 1 3 Haematopodidae Oystercatchers 1 1 1 1 Laridae Gulls and terns 2 2 3 4 Alcidae Auks, murres, puffins 6 7 9 9 Total 14 15 16 19

Taxonomic Distribution cover composed of salmonberry {Rubus of Marine Birds spectabilis), elderberry (Sambucus callicaipa), devil's club (Echinopanax horridus), and three species of Vaccinium (Heath There are 19 species of seabirds that breed 1915). There are 16 species of marine birds breed- along the Pacific coast of southeastern ing in the Alexander Archipelago. The major Alaska, British Columbia, and Washington seabird breeding colonies are located at Gla- (Table 1). Southeastern Alaska has the cier Bay and at St. Lazaria, Hazy, and For- largest number (17) of species. Errors in rester islands (Fig. 1; Table 2). Published sur- species identification are most likely with the veys of these colonies are available only for Larus gulls, particularly in southeastern St. Lazaria (Willett 1912) and Forrester is- Alaska where the herring gull (L. argentatus) lands (Heath 1915; Willett 1915). Several and glaucous-winged gull (L. glaucescens) authors have reported on seabirds from sur- breed in mixed colonies (Patten and Weisbrod rounding areas (Grinnell 1897, 1898, 1909; 1974). A similar situation exists in Washing- Swarth 1911, 1922, 1936; Patten 1974). There ton where the western (L. occidentalis) and have been no surveys of seabirds of southeast- glaucous-winged gulls intergrade (Scott ern Alaska since before the 1940's (J. King, 1971). Brandt's (Phalacrocorax penicillatus) G. Jr., personal communication). However, since and double-crested cormorants {P. auritus) census data are available for only two colo- are often difficult to identify from the air. nies, we discuss them in more detail. This would be a problem in Washington and the southwest coast of Vancouver Island, where the two species are locally sympatric. %'

Southeastern Alaska

The area under consideration is the 400-km- long Alexander Archipelago (Fig. 1). This complex pattern of islands, bays, and inlets is PACIFIC OCEAN characterized by extremely high precipitation and typical cool marine temperatures. Aver- SCALE ^ age annual precipitation in the Sitka area is BOkirT"^^^ 245.4 cm (1931-60), and the average annual • 500-5000Prs [• 5000 50 000 temperature is 6.3° C (U. S. Weather Bureau 1974). As a consequence of this cool, humid environment, most of the islands are densely covered with conifers, chiefly Sitka spruce Fig. 1. Map of southeastern Alaska showing major {Picea sitkensis) and hemlock (Tsuga hetero- seabird breeding colonies: 1—North Marble phylla), and an almost impenetrable shrub Island; 2— Forrester Island. SEABIRDS OF ALASKA, BRITISH COLUMBIA, AND WASHINGTON 75

Table 2. Population estimates of seabirds breeding on St. Lazaria and Forrester islands, southeastern Alaska (data from Willett 1912 and 1915).

St. Lazaria Island Forrester Island

Number Percent Number Percent Bird species of pairs of total of pairs of total

Fork-tailed storm-petrel 2,000 8.0 10,000 6.0 Leach's storm-petrel 20,000 80.0 50,000 30.0 Pelagic cormorant 150 0.6 150 0.0 Black oystercatcher 4 0.0 50 0.0 Glaucous-winged gull 300 1.2 8,000 4.8 Herring gull 220 0.0 Common murre 300 1.2 20,000 12.0 Pigeon guillemot 150 0.6 300 0.0 Ancient murrelet 20,000 12.0 Cassin'sauklet 2,000 1.2 Rhinoceros auklet 75 0.0 20,000 12.0 Horned puffin 12 0.0 1,100 0.7 Tufted puffin 2,000 8.0 35,000 21.0 Total 24,991 166,820

The studies by Willett (1912, 1915) and At the present time, it is impossible to draw Heath (1915) provide some base-line informa- any conclusions about changes in population tion on species composition and abundance density and distribution for most of the sea- with which future studies on St. Lazaria and birds breeding in southeastern Alaska. Ade-

Forrester islands can be compared (Table 2). quate data are available only for St. Lazaria The somewhat greater species diversity on and Forrester islands where Willet and Heath Forrester Island is primarily due to its provided the only early extensive census data greater size and more suitable soil type for an- for this part of Alaska. cient murrelets {Synthliboramphus antiquus) and Cassin's auklets {Ptychoramphus aleutica), species that are absent on St. Lazaria. British Columbia Storm-petrels {Oceanodroma spp.) are the most numerous species on both islands, but The rugged British Columbia coastline is there are proportionately more storm-petrels characterized by 930 km of islands and inlets

(88%) on St. Lazaria than on Forrester (36%). (Figs. 2, 3). With the exception of the inner On the other hand, there are many large, bur- southern portion, this coast is mostly unin- rowing alcids on Forrester Island. Nearly a habited. The physical characteristics of the third of the birds on Forrester are rhinoceros offshore islands are similar to those found off auklets (Cerorhinca monocerata), tufted the Washington coast. Descriptions of some puffins {Lunda cirrhata), and horned puffins of these islands and the 15 species of breeding (Fratercula comiculata). seabirds on them have been given by Drent The species composition of seabirds breed- and Guiguet (1961), Guiguet (1971), and ing on other islands is similar to that found on Summers (1974). Forrester and St. Lazaria islands but less A detailed analysis of British Columbia sea- abundant. In Glacier Bay, for example, the birds is not presented here since a more only population data available are those pro- thorough analysis is in preparation by R. W. vided by Patten (1974) for North Marble Is- Campbell and R. H. Drent (manuscript). In- land: pelagic cormorants, Phalacrocorax stead, we present seabird population esti- pelagicus (30 pairs); black oystercatchers, mates available for the Province up to the

Haematopus bachmani (8); herring guUs (7); summer of 1975; Tables 3 and 4 summarize glaucous-winged gulls (500); common murres, these estimates for the five major portions of

Uria aalge (18); pigeon guillemots, Cepphus coastal British Columbia. The coast of British

columba (60); horned puffins (4); and tufted Columbia contains a myriad of small islands puffins (30). where there may be small numbers of breed- 76 D. A. MANUWAL AND R. W. CAMPBELL

ALASKA

'^ QUEEN \} charlottes) '^X^'^^ SOUND

PACIFIC OCEAN PACIFIC OCEAN

• 500- 5000 Pai 05000-50000

Fig. 2. Map of northern British Columbia showing Fig. 3. Map of southern British Columbia showing sites of major seabird breeding colonies: 1 — sites of major seabird breeding colonies: 1—Tri- Skedans Island; 2—Limestone Island; 3—Ag- angle Island; 2— Cleland Island. glomerate Island; 4— Bischoff Island; 5—Ramsey Island; 6— Alder Island; 7—Rankins Island.

ing seabirds. Many of these have not been cen- where breeding seabirds are found— the west- sused and are too numerous to include in ern coast of the Olympic Peninsula and the Tables 3 and 4. San Juan Islands, including the Strait of Juan More than half of the breeding seabirds in de Fuca. British Columbia are found on the east coast On the Olympic Peninsula, seabirds breed of the Queen Charlotte Islands, and the fork- on the offshore rocks, islands, and precipitous tailed storm-petrel {Oceanodroma furcata) cliffs from Copalis Beach to Cape Flattery

comprises more than half of that total. How- (Fig. 4). The offshore rocks and islands ever, new unpubUshed data (K. Vermeer) for throughout this area (except Tatoosh Island) Triangle Island and the northwest coast of are now included in the Washington Islands Vancouver Island indicate that the popula- National Wildlife Refuge. Most of the larger tion figures in Table 3 for this area are under- rocks and islands have dense stands of sal- estimates. Nevertheless, these two regions monberry, salal, and grasses, and a few sup-

have nearly 80% of all the breeding seabirds port stands of stunted conifers (Fig. 5); most in the Province. This results from the very are inaccessible to man. The adjacent coast is large populations of the rhinoceros auklet and dominated by the Olympic rain forest where tufted puffin on Triangle Island and the fork- the mean annual precipitation is about tailed storm-petrel, ancient murrelet, and Cas- 337.1 cm (U. S. Weather Bureau 1956, 1965a, sin's auklet on various islands on the east 19656). coast of the Queen Charlotte Islands Because the San Juan Islands lie northeast

(Table 3). of the Olympic Peninsula and east of Van- Continuing surveys of breeding seabirds are couver Island (Fig. 6) they are in a rain being conducted by personnel of the British shadow; however, because of highly variable Columbia Provincial Museum and the Cana- topography and aspect, most islands have a dian Wildlife Service. diverse assemblage of plant communities (Franklin and Dyrness 1973). Exposed south- Washington State facing slopes are occupied by grassland vegetation and frequently by scattered trees, General Environment usually Pseudotsuga menziesii and Arbutus For this report, we have distinguished two menziesii. Most of the seabird colonies are lo- major geographical areas in Washington cated on rather small exposed islands with I1 (1 I1 t

SEABIRDS OF ALASKA, BRITISH COLUMBIA, AND WASHINGTON 77

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Table 4. Breeding seabird population estimates for British Columbia^'^

Population Percent Geographic location estimate of total

Straits of Georgia and Juan de Fuca 14.385 9.2 Southwest Coast of Vancouver Island 9,575 6.1 Northwest Coast of Vancouver Island 38,600 24.6 West Coast of Queen Charlotte Island 7,733 4.9 East Coast of Queen Charlotte Island 84,530 54.0 Prince Rupert to Queen Charlotte Strait 1,824 1.2 Total 156,647 100.0

^Estimates only for colonies of 100 or more birds. ''Estimates are in number of pairs.

short, grassy, shrubby vegetation. In general, these islands are not suitable for burrowing •JUAN DE FUCA species. In the Strait of Juan de Fuca, the two most important sites are Smith and Protection islands. Both are composed of glacial deposits and heavy sod that has developed under dense grassy vegetation (Fig. 7). Consequently, these two islands support most of the burrowing seabirds in the region. Unfortunately, both islands have historically been subjected to much human disturbance (Richardson 1961; Manuwal 1974). The existing information on seabird colonies in both the coastal and San Juan Island areas has been largely derived from aerial surveys by the U. S. Fish and Wildlife Service. These surveys are inherently biased toward surface-nesting species such as gulls and cormorants. Population estimates for guillemots, auklets, storm-petrels, and puffins are less accurate. Some additional information obtained by direct island visitation has been provided by Kenyon and Scheffer (1961), Richardson (1961), Thoresen and Galusha (1971), G. Eddy (unpubUshed data), and D. A.

Manuwal (unpubUshed data). Although other Fig. 4. Map of the Olympic Peninsula of accounts of Washington seabirds are avail- Washington State showing sites of major seabird breeding colonies: Protection Island; 2— able, the references Usted above are specifi- 1— Carroll Island; 3— Destruction Island. cally oriented toward population assessment.

for 12 species of seabirds breeding on 24 Olympic Peninsula major sites, it represents only the majority and not the total number of breeding seabirds Despite the large number of offshore rocks, on the Pacific coast of Washington. About islets, and islands along the Pacific coast of 74% of the entire Washington seabird popula- Washington, significant seabird colonies are tion resides on the coastal rocks and islands. present only on about 30 islands. Since Major colony sites with more than 2,500 Table 5 summarizes the population estimates breeding pairs are Grenville Arch, SEABIRDS OF ALASKA, BRITISH COLUMBIA, AND WASHINGTON 79

Fig. 5. Photograph of Destruction Island off the coast of Washington.

Willoughby Rock, Destruction Island, Cake guillemot). In all, about 31,000 seabirds of 7 Rock, Carroll Island, and Bodelteh Island. species breed in the San Juan Island area. More intensive censusing, especially of noc- Breeding seabird population estimates for 49 turnal burrowing species will undoubtedly of the 86 nesting sites are given in Table 6. raise the population estimates for these and other islands off the coast. About 54% of the total coastal population is composed of the common murre and rhinoceros auklet.

San Juan Islands

There are about 86 actual or potential seabird colony sites in this area; 25 (30%) are now considered important. Eleven islands are under Federal protection as National Wildlife Refuges. Part of Protection Island is owned by the Washington State Game Department to protect the largest rhinoceros auklet colony STRAIT OF JUAN DE FUCA in the State. Most colony sites are on small islands with poorly developed soil which prevents burrowing species from using them. Consequently, the dominant species are sur- Fig. 6. Map of the San Juan Archipelago showing face nesters (such as gulls and cormorants) sites of major seabird breeding colonies: 1—Viti and rock-crevice nesters (like the pigeon Rocks; 2—Colville Island; 3—Smith Island. 80 D. A. MANUWAL AND R. W. CAMPBELL

^' ^-^ '^ ^-' Washington. The glacial deposits ^'t^^^S:^:^^::^the composition "^i^:^^^^of the cUff faces. I

SEABIRDS OF ALASKA, BRITISH COLUMBIA, AND WASHINGTON 81

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Table 6. Breeding seabird population estimates for the San Juan Islands and Strait ofJuan de Fuca, Washington, 1973-75.^

Species

Cormorants Black_,i i Glaucous- Double- oyster- winged Pigeon Rhinoceros Tufted Breeding site crested Pelagic catcher gull guillemot auklet puffin Total

Bare Island — 50 120 + 173 Barren Island — — Battleship Island — — Bird Rocks 30 — 320 — 350 Cactus Island — — 1 1 Castle Island — — __ 30 30 Colville Island - 40 1 1,000 — 1,041 Danger Island — — — 125 7 132 Decatur Island — — Eliza Island — — __ 3 1 4

Eliza Rock — — — 1 — 1 Flat Top Island — — — — + 4- Flower Island — 17 — 90 — 107 Goose Island — — — 60 — 60 Gull Rock — — + 125 7 132 GuUReef -. - — HaU Island - — 275 276 Harbor Rock — — Iceberg Island — — Johns Island — — 1 Long Island — — 80 88 Low Island — — 75 17 93 Lummi Rocks — 4 4 i). Matia Island — + + Mummy Rocks — — 55 55 Minor Island — ^ 100 100 O'Neal Island — — Patos Island — — 20 + 20 North Peapod Island — — 220 2 223 South Peapod Island — — 75 2 78 Pearl Island — — Pointer Island — — 58 2 60 Protection Island " 3 110 1,500 30 9,200 35 10,881 Puffin Island — — 350 15 366 Ripple Island — — Sentinel Island ~ — 10 10 Sentinel Rock — — X 1 Skip Jack Island — — 75 20 95 Smith Island — 20 6 10 30 600 666 Speiden Island — —

South Sister Island 2 11 1 131 145 Middle Sister Island — — 1 22 23 North Sister Island — — 2 412 3 417 Viti Rocks 29 80 1 387 1 498 Waldron Island — — 2 2 Williamson Rocks — 67 1 346 2 416 Whale Island — — 1 70 71 White Rock — — + 125 13 138 Yellow Island — — Total per species 64 395 34 6,234 194 9,800 37 16,758 Percent of total population 0.4 2.3 0.2 37.2 1.2 58.5 0.2 100.0

"Estimates are numbers of pairs. SEABIRDS OF ALASKA, BRITISH COLUMBIA, AND WASHINGTON 83

Even though this does not represent all the Table 7. Nest-site preference for seabirds colonies, it covers the most important islands breeding from Cape Fairweather, Alaska, and those islands where there appears to be to the Columbia River, Washington. potential for seabird breeding. Nest-site type The major colony sites with more than 250 Bird species breeding pairs are located at Protection and Burrow-rock crevice Smith islands. Bird Rocks, Colville Island, Diurnal Pigeon guillemot Hall Island, North and South Peapod rocks. Horned puffin Puffin Island, North Sisters, Viti Rocks, and Tufted puffin Nocturnal Fork-tailed storm-petrel Williamson Rocks (Fig. 6). Glaucous-winged Leach's storm-petrel gulls are the predominant species on all these Kittlitz's murrelet islands except Protection and Smith islands, Ancient murrelet where there are large colonies of rhinoceros Cassin'sauklet auklets. Rhinoceros auklets (65%) and glau- Rhinoceros auklet cous-winged gulls (32%) make up 97% of the Open nests total San Juan Islands seabird population. Flat or slope Double-crested cormorant Brandt's cormorant Glaucous-winged gull Nest-site Preferences Herring gull Western gull Black oystercatcher Food supply and availabiUty of nest sites Cliff face Pelagic cormorant are two critically important factors influenc- Common murre ing the distribution and abundance of sea- Black-legged kittiwake birds. Whereas information on general diet Tree branch Marbled murrelet composition is known for most seabird species, we know little about the availability of favored seabird prey. The dynamics of seabird food chains is reviewed elsewhere in these have been gathered by aerial surveys. Conse- proceedings. quently, the burrow and rock crevice cate- The nest-site preferences for seabirds of the gories are underestimated. The aerial survey northeast Pacific Ocean are given in Table 7, is appropriate for only about 43% of the birds and Table 8 indicates the proportion of sea- nesting on the Washington coast. birds that belong to specific nest-site cate- Northern and southern British Columbia gories. These preferences, in conjunction with provide another good example of habitat knowledge of the physical characteristics of availability as revealed through seabird popu- seabird habitat, permit a partial explanation lation estimates. The population data are of the present distribution and abundance of more comprehensive and have largely been seabirds. For example, if we compare the San gathered by island visitations. The islands in Juan Island habitats with those of the Wash- the northern portion are heavily vegetated ington coast, it is apparent that there are and many have well-developed soil into which more cliff-nesting species on the coast. This storm-petrels, auklets, and murrelets can bur- reflects the physical characteristics of the two row. Indeed, 96% of the seabird population habitats. There are few cliffs in the San Juan consists of nocturnal, burrow-nesting species. Islands, and those that exist are very un- In southern British Columbia, however, there stable. Colony sites in the San Juan Islands are more open-nest species, particularly glau- are typically on low, flat islands. Glaucous- cous-winged gulls and cormorants. winged gulls are the most abundant nesting Overall, 68% of the breeding seabirds found species there. Coastal islands, on the other along the northeastern Pacific coast are noc- hand, are either covered by dense vegetation turnal and nest in burrows or rock crevices or are large monolithic chunks of rock with (Table 8). The most conspicuous nesting birds few available flat areas. Population estimates such as gulls, cormorants, and murres, com- for the Washington coast are heavily biased prise only 22% of the total population. Conse- toward surface nesters, since most of the data quently, our current estimates of breeding 84 D. A. MANUWAL AND R. W. CAMPBELL

Table 8. Proportional nest-site preferences of Pacific coast seabirds."

Estimated number of pairs Percent of population

British Columbia British Columbia Total San Juan Washington San Juan Washin Site Northern Southern Islands coast Northern Southern Islands coast Population Percent

Burrow-rock crevice Diurnal 1,849 11,334 231 7,504 2.0 18.1 1.4 17.3 20,918 9.7 Nocturnal 90,347 30,600 9,800 17,070 96.0 48.9 58.6 39.4 147,817 68.1 Open nests Flat or slope 909 15,101 6,298 5,755 1.0 24.2 37.6 13.3 28,063 13.0 CUffface 982 5,525 395 12,945 1.0 8.8 2.4 30.0 19,847 9.2 Total 94,087 62,560 16.724 43,274 216,645

"Data for southeastern Alaska were inadequate to enable estimates of breeding pairs.

seabirds still underestimate the more secre- tion. Indeed, the biology of this species is per- tive, nocturnal, burrow-nesting species. haps the least known of the North Pacific colonial seabirds. In southeastern Alaska, this species is outnumbered by at least 5 to 1 Population Changes by the Leach's storm-petrel (Oceanodroma leucorhoa). The reasons for this are poorly The available data are inadequate to detect understood. There is some evidence that the changes in population distribution and den- numbers of breeding fork-tailed storm-petrels sity for most species (Table 9). In Washing- on Forrester Island may fluctuate drastically ton, for instance, limited unsubstantiated in- from one year to the next (Gabrielson and formation suggests an overall decline of the Lincoln 1959). double-crested cormorant and tufted puffin in the San Juan Island area. Likewise, there Leach's Storm-petrel (Oceanodroma seems to be an increase in glaucous-winged leucorhoa) gulls there. In British Columbia, Drent and Of the two subspecies of this petrel (O. /. leu- Guiguet (1961) were able to detect changes in corhoa and O. I. beali), only O. /. beali is found some species. For example, they noted in- in southeastern Alaska. The leucorhoa sub- creases in the double-crested cormorant, pela- species is more northerly in distribution. gic cormorant, and glaucous-winged gull. No Where both fork-tailed and Leach's storm- change was observed in the tufted puffin. petrels are sympatric, Leach's predominates; Since then, the Brandt's cormorant has estab- however, this relationship becomes more un- lished a colony in Barkley Sound (Guiguet predictable in British Columbia and Washing- 1971). The data in southeastern Alaska are in- ton. This species is undoubtedly widespread adequate for all species except, perhaps, the in the islands the Alexander Cassin's auklet which Gabrielson and Lincoln forested of Archipelago. (1959) reported to be declining throughout Alaska. In short, no definitive statements can Double-crested Cormorant now be made concerning changes in seabird (Phalacrocorax auritus) population numbers. The double-crested cormorant apparently does not breed in southeastern Alaska since Species Accounts Willett (1912), Gabrielson and Lincoln (1959), and S. Patten (personal communication) do Fork-tailed Storm-petrel not report breeding colonies for the area. The {Oceanodroma furcata) largest populations occur in southern British Storm-petrels are especially difficult to cen- Columbia principally in the Gulf Islands, sus because they are nocturnal, and the bur- where 71% of all breeding double-crested cor- rows and rock crevices where they breed are morants are found (Table 10). According to often difficult to locate, especially in mixed- Jewett et al. (1953), this species was less com- species colonies. The census data are inade- mon in Puget Sound than was Brandt's cor- quate to determine whether there have been morant, but is certainly not the case today changes in population density and distribu- (D. A. Manuwal, unpublished data). The only SEABIRDS OF ALASKA, BRITISH COLUMBIA, AND WASHINGTON 85

Table 9. Distribution and status of marine birds breeding along the Pacific coast of Washing- ton, British Columbia, and southeastern Alaska. (X = known to breed in the region; ? = data insufficient; + = evidence indicates an overall increase in size of population; - = evidence indicates an overall decrease in size of population; = no population change.)

British Southeastern Washington Columbia Alaska

Family and species Common name Presence Status Presence Status Presence Status Hydrobatidae Oceanodroma furcata Fork-tailed X ? X ? X 7 storm-i>etrel 0. leucorhoa Leach's storm-petrel X ? X - X ? Phalacrocoracidae Phalacrocorax auritus Double-crested X - X + cormorant P. penicillatus Brandt's cormorant X ? X ? P. pelagicus Pelagic cormorant X ? X + X 7 Haematopodidae Haematopus bachmani Black oystercatcher X 7 X + X ? Laridae Lams glaucescens Glaucous-winged gull X + X + X 7 L. occidentalis Western gull X ? X 9 L. argentatus Herring gull X ? Rissa tridactyla Black-legged X ? kittiwake Alcidae Uria aalge Common murre X ? X - X 7 Cepphus columba Pigeon guillemot X ? X + X 7 Brachyramphus marmoratus Marbled murrelet X ? X 7 X 7 B. brevirostris Kittlitz's murrelet X ? Synthliboramphus antiquus Ancient murrelet X ? X 7 Ptychoramphus aleuticus Cassin's auklet X ? X ? X - Cerorhinca monocerata Rhinoceros auklet X ? X + X 7 Fratercula comiculata Horned puffin X 7 Lunda cirrhata Tufted puffin X - X X 7 Total species 14 15 16

common cormorants in the San Juan Islands species. Only one more northerly colony are the pelagic and double-crested species. exists, on Sartine Island off Vancouver Island The double-crested cormorant seems to have (Vermeer et al. 1976). Brandt's cormorant declined in numbers on both coastal and in- comprises about 85% of the cormorant popu- land waters. On the basis of his observations, lation in Oregon (U. S. Fish and Wildlife Ser- R. W. Campbell believes that this species is vice, unpublished data). However, in Wash- increasing in British Columbia. ington it is only about 9% and in British Columbia 3% of the total cormorant Brandt's Cormorant (Phalacrocorax population. penicillatus) Comparing information in Jewett et al. Brandt's cormorant is the least abundant of (1953) with the current situation, it is ap- the three cormorant species that nest in the parent that there has been a drastic change in study area. Washington is at the northern- the distribution and probably in the numbers most edge of the breeding distribution of this of this species in Washington. Today, there t1 t 1

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are no Brandt's cormorant colonies in the San ing biology of this species in southeastern Juan Islands or Strait of Juan de Fuca. Yet Alaska is by Patten (1974) for Glacier Bay. Jewett et al. (1953) reported colonies at Bell- Glaucous-winged gulls are apparently increas- ingham Bay and on Lopez and Matia islands. ing in British Columbia (R. W. Campbell, un- We have observed juvenile Brandt's cor- published data) and in Washington (T. R. morants in the San Juan Islands during the Wahl, personal conmiunication). This increase summer. This species may be particularly sus- is undoubtedly a result of the proximity of ceptible to human disturbance, since all three breeding colonies to garbage dumps and com- areas listed above are heavily used in the sum- mercial fishing fleets in both Canada and the mer for recreation. United States. Little is known about changes in populations of gulls in southeastern Alaska. Pelagic Cormorant (Phalacrocorax pelagicus) Western Gull (Larus occidentalis) The distribution of breeding colonies of the The western gull is the common breeding pelagic cormorant is strongly determined by gull of the Washington outer coast; however, the availability of the steep cliffs on which it there is increased interbreeding with glau- constructs its nest. This is the only common cous-winged gulls northward from Destruc- cormorant in southeastern Alaska. Through- tion Island to Tatoosh Island. The percentage out its extensive range, this species is gener- of glaucous-winged gulls steadily increases ally found breeding in small numbers. Noth- until Vancouver Island and the Strait of Juan ing is known about fluctuations in its num- de Fuca, where western gulls are rare. Popula- bers in Alaska. tion estimates of gulls on the outer coast of This species is common in both British Washington are derived primarily from aerial Columbia and Washington; nesting sites are flights. This makes identification of gulls dif- of the same type as those in Alaska except in ficult, and in view of the amount of interbreed- the San Juan Islands, where 200-300 birds ing, it is probably impossible to classify many nest on cliff faces composed of glacial de- of the breeding gulls as to species. Western posits. Here, there is frequent nest loss due to gulls appear to be increasing in the Grays slippage off the cliff face; this loss is espe- Harbor area (G. D. Alcorn, personal com- cially severe on Smith and Protection islands. munication). There do not appear to be any changes in the distribution of pelagic cormorants, but an accurate assessment of abundance is impos- Herring Gull (Larus argentatus) sible from the data currently available. The herring gull is typically found in inland Alaska but can be found uncommonly along

the coast of southeastern Alaska, where it Glaucous-winged Gull (Larus glaucescens) often forms mixed colonies with glaucous- The glaucous-winged gull is the character- winged gulls. These two species apparently istic gull of southeastern Alaska and British hybridize where they are sympatric (William- Columbia. In Washington, it is the dominant son and Peyton 1963; Patten and Weisbrod gull in the San Juan Island area but inter- 1974; Patten 1974). breeds with the western gull on the Washing- ton outer coast from Tatoosh to Copalis Black-legged Kittiwake (Rissa tridactyla) Beach (Scott 1971). In Alaska, it is widely distributed and locally abundant on Forrester Is- The black-legged kittiwake is found only in land, St. Lazaria, and throughout Glacier Bay the northern portions of southeastern Alaska. (S. Patten, personal communication). The It apparently is a common breeding bird in biology of this species has been extensively Glacier Bay National Monument (S. M. studied in the southern part of its range, espe- Patten, Jr., personal conmiunication). No cially by Vermeer (1963) and James-Veitch population estimates are available for this and Booth (1954). The only study of the breed- species other than that it is locally abundant. 88 D. A. MANUWAL AND R. W. CAMPBELL

Common Murre (Uria aalge) Ancient Murrelet (Synthliboramphus antiquus) Common murres are common in southeastern Alaska and the coast of Washington but Ancient murrelets appear to be locally com- breed only in small numbers in British Colum- mon throughout southeastern Alaska. Their bia and are absent in the San Juan Islands. presence is probably strongly dependent upon Since this species usually prefers cliffs or the a suitable soil in which to excavate burrows. tops of inaccessible rocks, they are probably The only available population estimates are limited by island topography in British those by Willett (1915) for Forrester Island Columbia, and are most certainly so limited in (Table 1). Censusing this species is especially the San Juan and Gulf Island groups. difficult because its burrows are easily con- In Alaska, common murres breed in un- fused with those of Cassin's auklet. There are known numbers in Glacier Bay and in large no studies of this species in southeastern numbers on St. Lazaria, Forrester, and the Alaska; however, it has been well studied in Hazy islands. No data on population changes the Queen Charlotte Islands to the south by are available for any of the three regions. Sealy (1975).

Pigeon Guillemot (Cepphus columba) Cassin's Auklet (Ptychoramphus The pigeon guillemot is common through- aleuticus) out the region from Fairweather to Cape A synthesis of literature and unpublished Washington. Even though it is not truly colo- observations led Gabrielson and Lincoln nial, it be locally there may abundant where (1959) to conclude that Cassin's auklet has are suitable nest sites. Since these nest sites greatly decreased in numbers and is not abun- are usually difficult to find, esti- population dant anywhere in Alaska. They also con- mates are seldom accurate, usually being concluded that the colony on Forrester Island servative. It is evident that guillemots appear (Table 1) was the only well-documented colony to be small in number when compared with in southeastern Alaska. Fishermen in the other seabirds nesting at major colony sites in southeastern Alaska area occasionally see the north Pacific region (Table This dis- 10). this species (M. E. Isleib, personal communi- parity may be exaggerated by the difficulty of cation), but it is apparently still uncommon censusing guillemots. though more widespread than just Forrester Island. The nocturnal habits and burrowing in Marbled Murrelet (Brachyramphus dense vegetation makes censusing this marmoratus) species very difficult. Nothing is known about Since the marbled murrelet has been found the ecology of this species in Alaska. to nest in coniferous forests (Binford et al. 1975), traditional census techniques are un- Rhinoceros Auklet (Cerorhinca monocerata) suitable. This is in species common southeast- Rhinoceros auklets seem to be found breed- ern Alaska (Gabrielson and Lincoln 1959), in ing only on islands where there is a well-de- British Columbia (Drent and Guiguet 1961), veloped soil in which to excavate their exten- and in Washington al. (Jewett et 1953). sive burrows. From the Umited evidence available, it appears that the largest rhinoceros Kittlitz's Murrelet (Brachyramphus auklet populations probably are to be found in brevirostris) southeastern Alaska. Willett (1912) found a The difficulties in assessing breeding popu- very large population on Forrester Island lations of Kittlitz's murrelet are the same as (Table 2), and the species has been found in those for the marbled murrelet. This species the summer in the Barren Islands east of nests on the ground at high elevation near the Kodiak Island (E. P. Bailey, personal com- coast (Bailey 1973). The largest concentra- munication). More intensive surveys of the tions are in the vicinity of Glacier Bay Na- Alexander Archipelago will probably reveal tional Monument (Gabrielson and Lincoln other populations of this species. 1959). They are not found breeding in Wash- This species is less common in British ington or British Columbia. Columbia than either Alaska or Washington. SEABIRDS OF ALASKA, BRITISH COLUMBIA, AND WASHINGTON 89

A possible reason for this is lack of suitable and the largest colony in the Puget Sound nesting areas. In Washington, the two largest area is the 35 pairs on Protection Island colonies are at Protection Island in the Strait (D. A. Manuwal, unpubhshed data). of Juan de Fuca and Destruction Island on the outer coast. Smaller numbers exist on other coastal islands and on Smith Island in Discussion the Strait of Juan de Fuca. The Smith Island colony is an interesting one since it appears The total minimum estimate of the breeding that early human disturbance in the late 19th seabird populations of British Columbia and or early 20th century eUminated the species Washington is 216,500 pairs (Table 10). No from the island. In their discussion of Smith comprehensive estimates are available for Island, Jewett et al. (1953) made no mention breeding seabirds of southeastern Alaska. It of auklets, only of puffins and guillemots. is likely, however, that the number of breed- Couch (1929) did not record the species in ing seabirds in the Alexander Archipelago 1925. The colony now numbers about 600 may be equal to (or exceed) the populations of pairs. both British Columbia and Washington. Data are desperately needed from that area. Of the Horned Puffin {Fratercula comiculata) total seabird population in the study area (Table 10) 43% reside in northern British Although the horned puffin is one of the Columbia. The Washington State population most abundant seabirds in other parts of represents 28% of the total. Fork-tailed Alaska, it is much less abundant in the south- storm-petrels comprise almost 25% of all the eastern portion. In addition to the informa- breeding seabirds in the area under consideration discussed by Sealy (1973), it now appears tion. The Cassin's auklet is the next most that this species may breed as far south as numerous species (18% of the total). Triangle Island, British Columbia (K. Ver- It is apparent that current data are, for the meer, personal communication; D. A. Manu- most part, inadequate for assessing anything wal, personal observation). Here, as on For- but catastrophic changes in seabird breeding rester Island, it is greatly outnumbered by colonies. This inadequacy is due to inadequate the tufted puffin. No data are available on the censusing because of excessive reliance upon breeding or status of this species in the study aerial surveys; in the past, this has often been area. a result of insufficient funding. Of the several threats facing seabird popu- Tufted Puffin (Lunda cirrhata) lations, none may be as important as oil pollu- The tufted puffin is found breeding on tion. A general review of this subject is pre- scattered islands throughout the region. The sented elsewhere by Vermeer and Vermeer largest known colonies are on Forrester Is- (1975). It is apparent from this review that land, Alaska, Triangle Island, British Colum- the most vulnerable species are those that bia, and Carroll Island, Washington. It is dive beneath the sea surface, including all the notably absent from most of the gulf and San alcids and cormorants breeding along the Juan Islands. Even though puffins have ap- coast that are discussed in this paper. This parently never been numerous in the San group makes up almost 60% of all the breed- Juan Islands, their population has noticeably ing seabirds in this area. Unfortunately, our declined during the past 35 years. For knowledge of several of these species is scanty example, Jewett et al. (1953) reported a and our current census techniques are unsuit- colony of 50 pairs on Bare Island in 1937, but able for most of these birds. in 1973 only 2 pairs were counted (D. A. Studies of the changes in seabird numbers Manuwal, unpublished data). Likewise, in have been made in other oceans. For example, 1915 there were more than 250 pairs on Smith in Great Britain (Bourne 1972a, 19726; Harris Island, but by 1916 there were only 75 pairs 1970), eastern Canada (Nettleship 1973), and (Jewett et al. 1953). The decline is attributed the Atlantic coast of the United States (Kad- to rapid erosion of the glacial-deposit cliffs. lec and Drury 1968), two major trends seem There are no puffins on Smith Island today, apparent. First, there is an overall decline in 90 D. A. MANUWAL AND R. W. CAMPBELL

alcid and tern numbers. The decline in auks Specific islands where key populations may be due to their extreme vuhierability to exist should be carefully monitored for oil pollution (Bourne 1972a, 19726; Vermeer subtle changes in population density or and Vermeer 1975). The Atlantic puffin, how- species composition. ever, may be suffering the additional effects Increased study of the breeding biology of of gull cleptoparasitism (Nettleship 1972). seabirds should be carried out so that base- Secondly, there seems to be an increase in gull line reproductive characteristics can be populations on both sides of the Atlantic, par- determined. ticularly the herring gull and black-legged Detailed studies of the effects of human kittiwake. disturbance should be made, especially for Compared with the Atlantic coast of North species that breed near large coastal cities America and northern Europe, the data base or marine recreation areas. for seabird populations of the Pacific coast is poor. The fragmentary evidence now available indicates that there may be small population increases in the western and glaucous-winged References gulls and range extensions of the Brandt's P. Discovery of Kittlitz's murre- and double-crested cormorants and of the Bailey, E. 1973. a let nest. Condor 75:457. rhinoceros auklet (Scott et al. 1974). Whether Binford, L., B. Elliott, and S. Singer. 1975. Dis- these changes represent actual population in- covery of a nest and the downy young of the creases or displacements remains unclear. The marbled murrelet. Wilson Bull. 87:303-319. remote locations of most of the large Pacific Bourne, W. 1972a. The decline of auks in Great Britain. Biol. Conserv. 4:144-146. seabird colonies may provide unofficial pro- Bourne, W. 19726. Threats to seabirds. Int. Counc. tection from human interference. Intensive Bird Preserv. BuU. XI:200-218. surveys are needed to establish base-line in- Couch, L. 1929. Introduced European rabbits in the ventories in these areas. San Juan Islands, Washington. J. Mammal. 10:334-336. As a consequence of this first comprehen- Drent, R. H., and C. Guiguet. 1961. A catalogue of sive review of the status of breeding marine British Columbia seabird colonies. Occas. Pap. birds of the northeast Pacific coast of North B. C. Prov. Mus. 12. 173 pp. America, we recommend the following future Franklin, J., and C. Dyrness. 1973. Natural vegeta- research topics as necessary for the conservation of Oregon and Washington. U. S. For. Serv. Gen. Tech. Rep. PNW-8. 417 tion of this great international resource. pp. Gabrielson, I., and F. Lincoln. 1959. The birds of • Seabird colony census techniques should Alaska. The Stackpole Company, Harrisburg, be refined since almost 68% of the seabirds Penn., and Wildlife Management Institute, in this area are nocturnal and nest in bur- Washington, D. C. 922 pp. rows. The present reliance on aerial census- Grinnell. J. 1897. Petrels of Sitka, Alaska. Nidologist 4:76-78. ing, although economical, is inadequate to Grinnell, J. 1898. Summer birds of Sitka, Alaska. census most breeding seabird populations; Auk 15:122-131. more on-site surveys are needed. For sur- Grinnell, J. 1909. Birds and mammals of the 1907 face-nesting species and diurnal, burrow- Alexander Expedition to southeastern Alaska. 5:171-264. ing species, studies on species specific ac- Univ. CaUf. Publ. Zool. Guiguet, C. 1971. A list of seabird nesting sites in tivity cycles are needed so that census data Barkley Sound, British Columbia. Syesis 4:253- can be corrected for birds not observed at 259. the colony. For nocturnal, burrowing Harris, M. P. 1970. Rates and causes of increases of species seasonal burrow occupancy rates some British gull populations. Bird Study 17:325- must be determined so that burrow counts 335. Heath, H. 1915. Birds observed on Forrester Is- can be corrected for inactive burrows. land, Alaska during the summer of 1913. Condor • Comprehensive surveys should be made 17:20-41. every 3-5 years. James-Veitch, E., and E. Booth. 1954. Behavior and life history of the glaucous-winged gull. Walla • In 1980 a coordinated breeding bird survey WaUa CoU., Publ. Biol. 12. of the entire Pacific coasts of Mexico, Jewett, S., W. Taylor, W. Shaw, and J. Aldrich. Canada, and the United States should be 1953. Birds of Washington State. Univ. of Wash- conducted. ington Press, Seattle. 767 pp. SEABIRDS OF ALASKA, BRITISH COLUMBIA, AND WASHINGTON 91

Kadlec, J., and W. Drury. 1968. Structure of the Swarth, H. 1936. Origins of the fauna of the Sitkan New England herring gull population. Ecology District, Alaska. Proc. Calif. Acad. Sci. Ser. 4, 49:644-676. 15:59-78. Kenyon, K., and V. Scheffer. 1961. Wildlife surveys Thoresen, A., and J. Galusha. 1971. A nesting popu- along the northwest coast of Washington. Murre- lation study of some islands in the Puget Sound 42:29-37. let area. Murrelet 52:20-23. Manuwal, D. A. 1974. Conservation notes (Protec- U. S. Department of the Interior, Interagency Task tion Island). Pac. Seabird Group Bull. 1. Force. 1972. Environmental setting between Port Nettleship, D. 1972. Breeding success of the com- Valdez, Alaska, and west coast ports. Final Envi- mon puffin (Fratercula arctica L.) on different ronmental Impact Statement, Vol. 3. habitats at Great Island, Newfoundland. Ecol. Monogr. 42:239-268. U. S. Weather Bureau. 1956. Climatic summary of for 1931 through Nettleship, D. 1973. Tenth census of seabirds in the the United States—supplement of the United sanctuaries of the north shore of the Gulf of St. 1952, Washington. CUmatography Lawrence. Can. Field-Nat. 87:395-402. States 11-39. 79 pp. Patten, S. 1974. Breeding ecology of the glaucous- U. S. Weather Bureau, Environmental Data Ser- winged gull (Larus glaucescens) in Glacier Bay, vice. 1965a. Climatic summary of the United Alaska. M.S. Thesis. Univ. of Washington, States—supplement for 1951 through 1960, Ore- Seattle. 78 pp. gon. Climatography of the United States 86-31. Patten, S., and A. R. Weisbrod. 1974. Sympatry 96 pp. and interbreeding of herring and glaucous- U. S. Weather Bureau, Environmental Data Ser- winged gulls in southeastern Alaska. Condor vice. 19656. Climatic summary of the United 76:343. States—supplement for 1951 through 1960, Richardson, F. 1961. Breeding biology of the Washington. Climatography of the United States rhinoceros auklet on Protection Island, Washing- 86-39. 92 pp. ton. Condor 63:456-473. U. S. Weather Bureau, Environmental Data Ser- Scott, J. M. 1971. Interbreeding of the glaucous- vice. 1974. Climatological Data, Alaska Annual winged gull and western gull in the Pacific North- Summary 1974, 60:13. west. Calif. Birds 2:129-133. Scott, M., W. Hoffman, D. Ainley, and C. Zeille- Vermeer, K. 1963. The breeding ecology of the glau- maker. 1974. Range expansion and activity pat- cous winged gull (Larus glaucescens) on Man- terns in rhinoceros auklets. West. Birds 5:13-20. darte Island, B.C. Occas. Pap. B.C. Prov. Mus. Sealy, S. 1973. Breeding biology of the horned 13. 104 pp. puffin on St. Island, Bering with Lawrence Sea, Vermeer, K., D. A. Manuwal, and D. S. Bingham. zoogeographical notes on the north Pacific 1976. Seabirds and pinnipeds of Sartine Island, puffins. Pac. Sci. 27:99-199. Scott Island group, British Columbia. Murrelet Sealy, S. 1975. Feeding ecology of the ancient and 57(1):14-16. marbled murrelets near Langara Island, British Vermeer, K., and R. Vermeer. 1975. Oil threat to Columbia. Can. J. Zool. 53:418-433. on the west coast. Can. Field-Nat. Summers, K. 1974. Seabirds breeding along the birds Canadian 89:278-298. east coast of Moresby Island, Queen Charlotte Islands, British Columbia. Syesis 7:1-12. Willett, G. 1912. Report of George Willett, Agent Swarth, H. 1911. Birds and mammals of the 1909 and Warden stationed on St. Lazaria Bird Reser- Alexander Alaska Expedition. Univ. Calif. Publ. vation, Alaska. Bird-lore 14:419-426. Zool. 7:9-172. Willett, G. 1915. Summer birds of Forrester Island, Swarth, H. 1922. Birds and mammals of the Stikine Alaska. Condor 19:15-17. River Region of northern British Columbia and Williamson, F. S. L., and L. Peyton. 1963. Inter- southeastern Alaska. Univ. Calif. Publ. Zool. breeding of glaucous-winged and herring gulls in 24:194-314. the Cook Inlet region, Alaska. Condor 65:24-28.

THE BIOLOGY AND ECOLOGY OF MARINE BIRDS IN THE NORTH

Trophic Relations of Seabirds in the Northeastern Pacific Ocean and Bering Sea

David G. Ainley Point Reyes Bird Observatory Stinson Beach, California 94970 and Gerald A. Sanger'

National Marine Fisheries Service Marine Mammal Division Seattle, Washington

Abstract

Literature on the diets of seabirds is reviewed for 70 species found in five subarctic oceanographic regions of the northeastern North Pacific Ocean and Bering Sea. Species inhabiting estuaries and sheltered bays are not included. The diets of cormorants, marine ducks, alcids, and marine raptors are best known; less information is available for loons, grebes, petrels, and gulls. Enough is known, however, to broadly characterize the diet of each species. Less than 7% of all species feed on one type of prey, about 60% feed on two or three types, and the rest feed on four or more types. Only 12% of all species feed on eight or more types of prey. Most seabirds (77%) feed as secondary and tertiary carnivores. Where overlap in diet exists, seabirds partition resources through use of different feeding methods, selection of different-sized prey, and zonation of habitat. Species that have specialized diets are probably more susceptible than others to local environmental catastrophies. Species whose feeding methods are highly adapted for exploitation of resources in polar and subpolar habitats are not adapted for coping with oil pollution. Competition between birds and man for marine resources can sometimes benefit seabirds and at other times harm them. More research is needed on seabird feeding relations so that the ecological roles played by marine birds can be defined and placed in perspective. Such work should be conducted at the community level, year-round, and should be so conducted as to facilitate comparison with biological oceanographic data.

The ecology, morphology, and much of the and Ashmole (1967), Ashmole (1971), Spring behavior of a seabird species are definable in (1971), and Sealy (1972). More concretely, in- terms of the food resources it exploits year- formation on trophic relations of seabirds is round and the spatial and temporal relations useful in several ways. In conjunction with between food and breeding sites. This general biological oceanographic data, it can provide point unifies such important reports as those insight into geographic location, marine habi- by Kuroda (1954), Bedard (1969a), Ashmole tat, depth, time of day, and general method of food capture by seabirds. Collected over for under- Present address: U. S. Fish and WUdUfe Service, several years, it can provide a basis Office of Biological Services, 1011 East Tudor standing annual differences in seabird breed- Road, Anchorage, Alaska 99503. ing phenology and success. Finally, supple-

95 96 D. G. AINLEY AND G. A. SANGER

merited with data on how much seabirds eat 50-70% or more of the birds breed in another and excrete, it is necessary for an understand- part of the world. To say that these nonbreeding of the energetic and ecological roles ing species have no significant impact on re- played by the birds in the functioning of source exploitation or on organization and marine ecosystems. evolution among breeding members would be Several studies that describe trophic rela- naive. Finally, few investigators have at- tions within seabird communities have helped tempted to fit birds into an entire ecosystem, to define the principals of community organi- including lower trophic level origins as well as zation pertaining to the exploitation of avail- fish, marine mammals, and man. able food resources and have given clues to The reasons for these gaps in study empha- food-chain pathways. Trophic relations have sis are readily apparent: the inconvenience of been described for breeding communities in marine research during the winter when the Barents Sea (Uspenski 1958; Belopol'skii weather is stormy, the need for costly study 1961), in the tropical Pacific Ocean (Ashmole platforms (boats), and the difficulties in or- and Ashmole 1967; Ashmole 1968), in the ganizing the speciaUzed community of biolo- North Sea (Pearson 1968), and in the Chukchi gists required for such tasks. A less obvious Sea (Swartz 1966). The last-named study per- but important reason is that oceanographers tained most directly to the geographic region and fishery biologists have overlooked sea- discussed in this paper, but several other birds as important members of marine studies have provided sound information on ecosystems. segments of communities in the northeastern North Pacific and Bering Sea. These include the work on three species of auklets {Aethia, Diets of Seabirds in Cyclorrhynchus) in the Bering Sea (Bedard Western North America 1969a); investigations on cormorants and other fish predators in British Columbia by Relatively good information exists for most Munro (1941), Munro and Clemens (1931), and pelicaniformes of the region. A notable excep- Robertson (1974); studies of murres in Bristol tion is the brown pelican {Pelecanus occiden- Bay by Ogi and Tsujita (1973); observations talis), an endangered species. This is unfortu- on several species near the Pribilof Islands by nate because dietary information is important Preble and McAtee (1923); work on diving for understanding the species' ecology. Obser- species off Oregon by Scott (1973); and vations in eastern North America (Palmer studies of murrelets by Sealy (1975). 1962) and Peru (Murphy 1936) indicated that A review of available reports reveals three their diet consisted of fish that occur at the obvious gaps in the emphasis placed in sea- surface. The larger cormorants are pisci- bird food studies. First, few studies have ever vorous, particularly on schooling fishes that

considered in detail the trophic relations of occur at moderate to great depths (Table 1). seabird communities during the winter or non- The smaller cormorants feed more heavily on breeding season. Partial exceptions are the benthic fish and decapod crustaceans. Cor- works by Cottam (1939) and others on marine morants apparently feed only during daylight diving ducks, species that are seabirds only and then only for short periods because their during the winter, and by several researchers wettable plumage loses its buoyancy. Thus (Munro and Clemens 1931; Munro 1941; they remain relatively close (50 km) to nesting Robertson 1974) on seabirds in British Colum- and loafing areas. bia. Divoky (1976) studied diets of pack-ice Information on diets of marine ducks gulls during the nonbreeding season, but (Table 2) is more nearly complete than for those species are not included in the present most other seabirds. These birds fall into four analysis because they rarely are found south groups with some overlap: species feeding on of the Bering Strait. Second, no study has plants (Branta, Philacte, ylnas-type, and considered the trophic relationships of an en- Somateria fischeri); those feeding on benthic

tire seabird community, i.e., not just breeding crustaceans {Clangula hyemalis, Histrionicus species but also nonbreeding species. In the histrionicus, Polys tic ta stelleri, S. mollis- rather broad communities considered here. sima); those feeding on benthic molluscs (

TROPHIC RELATIONS OF SEABIRDS 97

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{Somateria spp. and Melanitta spp.); and smaller alcids, ancient and marbled murre- those feeding on fish {Mergus serrator, Clan- lets—Synthliboramphus antiquus and gula hyemalis, and Melanitta deglandi). A Brachyramphus marmoratus—(Table 5) and study by Perthon (1968), one of the few on a auklets (Table 6), feed on macrozooplankton: seabird's diet during most of a year, showed a crustaceans, and fish and squid larvae. Little seasonal change in diet for S. mollissima in is known about the food or feeding ecology of

Norway. In general, waterfowl seem to Kittlitz's murrelet (J3. hrevirostris). Its diet is specialize in their diets much more than other probably similar to that of the other murre- seabirds and, for that reason, are perhaps lets, especially the marbled murrelet, its allo- more restricted in their distributions. Some patric congener, but the diets of the other marine ducks are known to dive to consider- murrelets differ somewhat (Bedard 19696; able depths (reviewed by Kooyman 1974), but Sealy 1975). The Kittlitz's murrelet 's shorter usually they occur in shallow waters where bill suggests that it feeds more on inverte- plants and sessile invertebrates are readily brates. Alcids feed in deep or shallow water, available. depending on food distribution. Some alcid The summer diet of the pigeon guillemot species can be found at great distances from {Cepphus columba) is the best known among land, particularly in winter (Hamilton 1958; seabirds in the region being considered here Scott etal. 1971). (Table 3). Only in the extreme southern part Information on the diets of other seabirds in of its range (i.e., the California Channel Is- the region is fragmentary and sometimes lands) is there no information available on its rather anecdotal. A little is known about the diet. The species feeds on organisms, mostly feeding habits of loons {Gavia spp.) and fish, from rocky habitat and apparently can grebes {Podiceps spp. and Aechmophorus dive to considerable depths (FoUett and Ain- occidentalis), especially off British Columbia ley 1976). Because so much is known about (Table 7). The larger of these birds feed mainly guillemot diets during summer, a study of the on inshore fish, but as species become pro- winter diet would be valuable. gressively smaller, there is a tendency toward The diets of other alcids are known well eating crustaceans. Work by Madsen (1957) in enough to at least characterize them broadly. Denmark, indicated that loons and grebes The larger species, murres, tufted and horned tend to take prey near or on the bottom. Much puffins (Lunda cirrhata, Fratercula comicu- more information is available on these birds' lata), and the rhinoceros auklet (Cerorhinca diets at their freshwater breeding sites but monocerata), feed heavily on fish, mainly this provides only partial insight into what species that school in midwater (Table 4). To a they might eat in marine habitats. great degree, these birds are opportunistic, Information is especially poor for alba- feeding rather heavily at times on cephalo- trosses and petrels (order Procellariiformes) pods and crustaceans, particularly nektonic (Table 8). Yet, based on sheer numbers alone, forms. Morphological differences between the members of this diverse group are easily two murre species suggest that thick-billed among the most ecologically dominant of the murres {Uria lomvia) feed on benthic or- region (Sanger 1972; Ainley 1977). The ganisms much more than do common murres Laysan albatross (Diomedea immutabilis) (U. aalge), and that the latter species is more seems to be a squid specialist; the black- piscivorous (Spring 1971); however, field data footed albatross (D. nigripes), northern ful- on diets are barely adequate to confirm this. mar {Fulmarus glacialis), scaled petrel (Ptero- Ogi and Tsujita (1973) analyzed the stomach droma inexpectata), and the fork-tailed and contents of murres drowned in salmon gill Leach's storm-petrels (Oceanodroma furcata nets but did not separate the two species. For and O. leucorhoa) appear to be large, the present paper we considered them to be medium, smsdl, and tiny versions, respec- mostly U. aalge, since this species predomi- tively, of surface-feeding generalists that eat nates in the region of the food study (Barto- whatever they can find, including live and nek and Gibson 1972). Adult murres some- dead fish, squid, coelenterates, crustaceans, times eat different items than they feed to and other organisms. The shearwaters their chicks (Spring 1971; Scott 1973). The (Puffinus spp.) feed to an unknown degree on (

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schooling fish, squid, and crustaceans that sometimes associate with arctic terns during occur near the surface. For these very abun- feeding. dant shearwaters, that, unfortunately, is Finally, we must include raptors, particu- close to the extent of our knowledge both for larly the peregrine (Falco peregrinus) and bald the North Pacific, where they winter, and the eagle (Haliaeetus leucocephalus), because South Pacific, where they breed. Most petrels they are important predators on the smaller remain in oceanic habitats, but shearwaters, seabirds (White et al. 1971, 1973). Peregrines particularly the sooty shearwater (Puffinus have, in fact, been observed feeding on storm- griseus), and sometimes fulmars feed close to, petrels far at sea (Craddock and Carlson if not within, the inshore neritic habitat. A 1970). much better understanding of the diets of this group is sorely needed. Knowledge on the food of gulls, shorebirds, Trophic Relations Within and related species is surprisingly scanty in Seabird Communities view of all that is known about their breeding biology and social behavior. Little is known We have compared and summarized in about the marine food of phalaropes, but by general terms the food partitioning by species inference from their association with storm- in five rather broad oceanographic regions petrels, plankton-feeding whales, and conver- and their subdivisions in the northeastern gence lines (Martin and Myers 1969), their North Pacific and Bering Sea, based on the tiny size, and their method of feeding (picking specific details on diets presented in Tables 1 at minuscule items on the water surface), one through 10. The five broad regions, defined can guess that they feed on zooplankton and oceanographically by Dodimead et al. (1963) detritus. Skuas (Catharacta skua) and jaegers and Favorite et al. (1976) and modified by (Stercorarius spp.) apparently eat what they Sanger (1972), are shown in Fig. 1. The five can find at the surface, as well as whatever oceanographic regions (domains) were divided they can steal from gulls and terns. Almost all further into inshore neritic, offshore neritic, the literature on their feeding (Bent 1946) and oceanic habitats (Sanger and King, this dwells on accounts of their stealing from volume). We did not include estuarine habi- other birds. That spectacular behavior would tats or sheltered bays in the analysis. seem to be so energetically costly, though, The oceanic habitat includes waters of the that it is probably less important than we photic zone overlying the deep ocean and con- have been led to believe. Rather surprisingly, tinental slopes beyond the continental or the question of what foods the gulls and terns insular shelves. The Bering Sea and central eat in the eastern North Pacific is difficult to subarctic domains are largely made up of answer from the literature (Tables 9 and 10). oceanic habitat. The other three domains in- Some information exists for five of the larger clude both inshore and offshore neritic as well larids at isolated places, but little is known about food elsewhere in their respective ranges, and the diets of the seven smaller gulls and the terns are practically unknown. Studies on gull diets in the Atlantic region (e.g., Spaans 1971; Harris 1965) provide information on what to expect from the same species in the Pacific, but that information must be considered only in general terms because, the birds being somewhat opportunistic, their diets differ greatly from one locality to another (Ingolfsson 1967). A few observations are available for arctic terns Fig. 1. Schematic oceanographic domains of the {Sterna paradisaea) in Alaska, but little infor- subarctic Pacific regions (defined by Dodimead et mation exists for other terns (Table 10). Bent al. (1963) and Favorite et al. (1976) and modified (1921) noted that Aleutian terns (S. aleutica) by Sanger (1972). I

102 D. G. AINLEY AND G. A. SANGER

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Table 7. Diets of loons and grebes in different localities (x — major prey, o = minor prey, and • = incidental prey species}. CRUSTACEAN

a < X o'5;"a Euphausiid o „o ijc-a ^p«» Amphipod > Decapod Mysid .J

Location M< SOft.'^Oc^iC/a^-^taoct.ocooOi/)2 -^c Common loon IGavia immer) Alaska (Palmer 1962) • • o o o o o Vancouver Island (Munro and Clemens 1931) x Denmark (Madsen 1957) • o x • o Yellow-billed loon (G. adamsii)' Alaska (Cottam and Knappen 1939) • • o x Alaska (Bailey 1922) x Arctic loon (G. arctica)^ Vancouver Island (Palmer 1962) x Vancouver Island (Robertson, unpublished data) x California (Palmer 1962) x Denmark (Madsen 1917) • o • x x • x Red-throated loon tG. stellata)^ Oregon (Palmer 1962) x No. Atlantic (Palmer 1962) x x o Denmark (Madsen 1957) • o • x o • • Western grebe lAechmophorus occidentalis) Vancouver Island (Munro 1941) o • x x Vancouver Island (Robertson, unpublished data) x x Puget Sound (Phillips and Carter 1957) x • o o o Washington (Chatwin 1956) • x California (Palmer 1962) o • x x x • Red-necked grebe IPodiceps grisegena) - Pribilof Islands (Preble and McAtee 1923) o Vancouver Island (Wetmore 1924) x Vancouver Island (Munro 1941) x o x E. No. America (Wetmore 1924) o • o o x Horned grebe (P. auritus)^ Pribilof Islands (Preble and McAtee 1923) x o W. No. America (Wetmore 1924) x x • o o Vancouver Island (Munro 1941) x x o o • Denmark (Madsen 1957) o o o Eared grebe (P. nigricollisj^ W. No. America (Wetmore 1924) • x • o Vancouver Island (Munro 1941) x x o Denmark (Madsen 1957) x *

"Other incidental prey were copepods and isopods. •"Other Incidental prey were pholids in Denmark. "^Other incidental prey were copepods and cephalopods in North Atlantic areas. "^Other incidental prey were isopods in western North America and fish eggs near Vancouver Island. ' Other incidental prey were fish eggs in Denmark. TROPHIC RELATIONS OF SEABIRDS 107

Table 8. Diets of albatrosses and petrels in different localities (x = major prey, o = minor prey, and • = incidental prey species). CRUSTACEAN H FISH H :5 s 9

Diet Sjsaacoasjf: s Location M

Black-footed albatross (Diomedea nigripes} No. Pacific (Palmer 1962) x x x Aleutian Islands (Cottam and Knappen 1939) ox o x x California (Miller 1936, 1940) o o x x x x Laysan albatross (D. immutabilis) No. Pacific (Palmer 1962; Bartsch 1922; Fisher 1904) x Northern fulmar (Fulmarus glacialis) Pribilof Islands (Preble and McAtee 1923) o x Alaska (Gabrielson and Lincoln 1959) x x z Oregon (Gabrielson and Jewett 1940) x No. Atlantic (Hartley and Fisher 1936; x x Einarsson 1945; Fisher 1952) Flesh-footed shearwater {Puffinus cameipes) Australia (Oliver 1955; Serventyetal. 1971) x x x Pink-footed shearwater ^P. creatopus) California (Murphy 1936; Ainley, x x personal observation) E. Pacific (Cottam and Knappen 1939) x x Builer's shearwater (P. bulleri) SW Pacific (Falla 1934; Serventy et al. 1971) x x x Peru (Murphy 1936) x Sooty shearwater (P. griseus) Aleutian Islands (Sanger, personal observation) x x x British Columbia (Martin 1942; Sealy 1973a) x x x Oregon (Gabrielson and Jewett 1940) x California (Ainley, personal observation) x x Peru (Murphy 1936) x x x SW Pacific (Oliver 1955; Serventy et al. 1971) x x x Short-tailed shearwater iP. tenuirostris) Bristol Bay (Bartonek, personal communication) x Alaska (Cottam and Knappen 1939) x x x o No. Pacific (Palmer 1962; Kuroda 1955) x x x

• Australia (Serventy et al. 1971) x x x Bass Strait (Sheard 1953) x Mottled petrel (Pterodroma inexpectata) Pacific Ocean (Imber 1973) x E. No. Pacific (Kuroda 1955) - x Fork-tailed storm-petrel (Oceanodroma furcata) Pribilof Islands (Preble and McAtee 1923) X SE Alaska (Heath 1915) x British Columbia (Martin 1942) x California (Ainley, personal observation) x Leach's storm-petrel (0. leucorhoa) SE Alaska (Heath 1915) x California (PRBO, unpublished data) x x x x x So. California (Palmer 1962) x x No. Atlantic" (Palmer 1962) x x x x x

"Offal from wounded whales and seals, and bits of food, primarily crustaceans and fish, from feeding whales are important scavenger foods (Bent 1922). )

108 D. G. AINLEY AND G. A. SANGER

Table 9. Diets ofgulls in different localities (x = major prey, o = minorprey, and • = incidental prey species). CRUSTACEAN MOLLUSC FISH BIRD

H oJ as ^ fe a H o Diet 3 < "SQE; gSss -li-az o

Location M PO Q S. co O MorofelOa.0.gaaSO>-lco.gOM t o U O < fa-

Glaucous gull (Larus hyperboreus) St. Lawrence Island (Fay and Cade 1959) x x x Chukchi Sea (Swartz 1966) z xx x xxxx Pribilof Islands (Preble and McAtee 1923) x x x x x Vancouver Island (Munro and Clemens 1931) x > Glaucous-winged gull (L. glaucescens)' Pribilof Islands (Preble and McAtee 1923) x x x xxxx Alaska (Bent 1921) x No. Pacific (Sanger 1973) x • • Mandarte Island (Ward 1973) x x x x x Vancouver Island (Munro and Clemens 1931; x x x Robertson, unpublished data) Western gull (L. occidentalis)^ Farallon Islands (PRBO, unpublished data) x x o • x»» x xo oo x oo xooo Herring gull (L. argentatus)

No. Atlantic (Zelikman 1 96 1 x E. No. America (Bent 1946; Ainley, xxxxx x»ox personal observation) Vancouver Island (Munro and Clemens 1931) x x x Mew gull (L. canus)

Alaska (Bent 1921) x x X >

Vancouver Island (Munro and Clemens 1931) x x ) Heermann's gull (L. heermanni) California (Bent 1921) x x x X Bonaparte's gull IL. Philadelphia) E. No. America (Bent 1921) x x x Black-legged kittiwake IRissa tridactyla)^ Chukchi Sea (Swartz 1966) o * ooxoox Pribilof Islands (Preble and McAtee 1923) o Alaska (Bent 1921) oxx o Cook Inlet"* (Snarski, personal o o o x o x conmiunication) No. Atlantic (Hartley and Fisher x 1936; Zelikman 1961) Red-legged kittiwake (R. brevirostris) Pribilof Islands (Preble and x x x McAtee 1923) Sabine's gull (Xema sabini) Pt. Barrow (Banner 1954) x 09 ~ "Other incidental prey were isopods in the North Pacific. t'other incidental prey were the fish Merluccius at the Farallon Islands. Other incidental prey were isopods near the Pribilofs and in the Chukchi Sea, and amphipods in the latter area; Bent (1921) considered "crustaceans" to be major prey. 'Study conducted during period of breeding failure. TROPHIC RELATIONS OF SEABIRDS 109

Table 10. Diets of terns in different localities (x = major prey species). CRUSTACEAN FISH

Diet Ammodytes Location "Crustacean" Euphausiid Amphipod Mallotus Cottid larvae

Arctic tern (Sterna paradisaea) Pribilof Islands (Preble and McAtee 1923) Alaska (Bent 1921) No. Atlantic (Hartley and Fisher 1936)

Common tern {S. hirundo) E. No. America (Bent 1921) as some oceanic habitat. The boundary be- The above groupings are "tenuous" because tween the inshore and offshore neritic has yet prey in each category may represent more to be defined in terms of bird life, but it lies at than one trophic level, and a single prey that hne beyond which the bottom is too deep species could occur at one level one day or for a diving bird to exploit. A depth contour place and at another level the next day or thus defines the boundary. In the antarctic place, depending upon what it happened to be South Pacific, emperor penguins iApteno- eating. This is shown in Fig. 2, where the dytes fosteri) dive to depths of 275 m, but so parakeet auklet (Cyclorrhynchus psittaculus) far as is known, no comparable bird exists in can occur in the food web at different levels, the North Pacific. Some marine ducks and depending both on the prey it is eating and on loons reportedly dive to 50-60 m (Kooyman what its prey is eating. Even without this 1974). The inshore-offshore neritic boundary comphcation, many seabirds feed at more for seabirds may lie near the 70-m depth than one level in the food web. For instance, contour. murres eating euphausiids would be feeding Food resource partitioning by seabirds in at a different level than murres feeding on the five oceanographic domains are shown in larger fish. It might be "safer" to regard prey Tables 11-15. Within each domain, the com- organisms in level II as macrozooplankton, mon and usual members of the seabird com- prey organisms in level III as micronekton, munity are listed, and the major and minor and prey organisms (seabirds themselves) in categories in each of their diets are shown (on level IV as macronekton (after Sverdrup et al. the basis of available Uterature, Tables 1-10). 1942). The categories are grouped further, and rather tenuously, according to the trophic LARGE FISH level at which a bird is presumably feeding: I

^-^ I HI / z'' = herbivore, II = secondary carnivore, III = \ I ^-^ PARATH£MISTO ^\\ V ' / /' PTE " LIBELLULA ^ ' / A I / .^ tertiary carnivore, IV = final carnivore, and ^'' / I I K \ \ M^// ^^ " *^"- \^ jy^ It W Sc = scavengers (carnivorous) feeding at ' • / —? , ' > .^r.-* many levels. Birds at level I feed on large PHYTOPLANKTON algae and seed plants and are not directly part AUMODYTSS BI ^CALANUS^ of the same food webs involving other species. FINMARCHICUS These food webs originate with phytoplankton (Fig. 2). So far as is known, no bird feeds

>-^MGAMMARID | ~~*>«YSIDS on phytoplankton and few, if any, feed on -DETRITUS7rAMPt!IPpDS.yr-|-.f;OLY^H_AETESt;^r:7- microzooplankton; hence birds do not 2. Schematic food web of the parakeet auklet in generally feed as primary carnivores. An ex- Fig. the eastern Bering Sea (based on Bedard 1969a ception at times might be the least auklet and Dunbar 1946). Arrow sizes indicate relative (Aethia pusilla) when it feeds on small cope- importance of prey and Roman numerals refer to pods (see Bedard 19696). prey sizes (see text). 110 D. G. AINLEY AND G. A. SANGER

Table 11. Use of food resources by seabirds in the Bering Sea coastal domain. Information is from Tables 1-10. (Trophic level I = plants, II = secondary carnivore, III = tertiary carnivore, IV = upper level carnivore [on birds only in this table], Sc = scavenger on carrion, offal, or detritus [II-IV]; x = major food in diet, o = minor food, • = incidental food, ? = probable food.)

Habitat, bird trophic levels (I-IV, Sc), and food categories

Oceanic and offshore neritic Inshore neritic

II III IV Sc I II III IV Sc

=3 oa S «

S 2 o " 2 a (V 0) S 0) o to S 5 .5 3 2 >> "S 'r! ^ J3 "S "O 2 o 1 .2 J ,^ Ih k< u w ,^ .^ .M Seabirds O fc fa O CO o fa O CQ O

Gavia adamsii • G. arctica Podiceps grisegena o Diomedea nigripes X o o O X X X Fulmarus glacialis X o X X X X Puffinus griseus X X X P. tenuirostris X o X Oceanodroma furcata X o O X X X X Pkalacrocorax auritus o P. pelagicus X \j P. urile X Branta bernicla X Philacte canagica X Clangula hyemalis O X Histrionicus histrionicus O X Polys tic ta stelleri o X o o Samateria mollissima X X S. spectabilis o o o X S. fischeri X X Melanitta deglandi X M. nigra o o X Haliaeetus leucocephalus Falco peregrinus Phalaropus fulicarius X X o X X Lobipes lobatus X X X X Stercorarius spp. o X X ? X Larus hyperboreus o O O o o o o o o L. glaucescens o O O o o o o o o o L. argentatus o o o o o o o o o L. canus X o o o X Rissa tridactyla X X X Xema sabini X X o Sterna paradisaea X X o o Uria aalge X o X X o o U. lomvia X o X X X Lunda cirrhata ? X X Fratercula comiculata • X X Cepphus columba Synthliboramphus antiquus X X o Brachyramphus brevirostris z Cyclorrhynchus psittaculus X • • Aethia cristatella X X A. pusilla X o TROPHIC RELATIONS OF SEABIRDS 111

Table 12. Use of food resources by seabirds in the oceanic and offshore neritic habitats, Bering Sea domain. Information is from Tables 1-10. (Trophic level I = plants, II = secondary carnivore, III = tertiary carnivore, IV = upper level carnivore; Sc = scavenger on carrion, offal, or detritus [II-IV]; x = major food in diet, o = minor food, • = incidental food, ? = probable food.)

Bird trophic levels and food categories

II III IV Sc

<0 CS 0) > c -§ CS 5 s S 0) a O oo o « CO s en .2-C Si 1 2 8 .2 ^* .2 1 Seabirds o cu o fa fa o PQ O^ Diomedea nigripes X o X X X D. immutabilis X Fulmarus glacialis X o X X X X Puffinus griseus X X X P. tenuirostris X o X Pterodroma inexpectata X X Oceanodroma furcata X o X X X X Phalaropus fulicarius X X o Lobipes lobatus X X o Stercorarius spp. o X X ? X Larus hyperboreus X o o o X X ? X L. glaucescens X o X X ? X Rissa tridactyla X X X R. brevirostris X X X o Xema sabini X X o Sterna paradisaea X X o Uria aalge X o X X U. lomvia X o X X Lunda cirrhata ? X X Fratercula comiculata • X X Synthliboramphus antiquus X X Cyclorrhynchus psittaculus Aethia cristatella A. pusilla A. pygmaea

Information contained in Tables 11-15 can when more data become available. Except for be summarized to show characteristics of sea- the albatross and auklet, these species are bird trophic relations. One such characteristic members of the inshore neritic cohort. Food is the range of diet breadth or diet complexity specialization does not seem to be character- (Table 16). Few species (about 6%) feed on istic of oceanic birds in particular or of most only one type of prey and might, therefore, be seabirds in general. referred to as "specialists." Included are Most species (roughly 53% in any commu- eared grebe (Podiceps caspicus), Laysan alba- nity) include two or three prey categories in tross, brown peUcan, emperor goose (Philacte their diets—usually midwater schooling fish, canagica), black brant (Bemicia bemicla), squid, and crustaceans. These birds include peregrine falcon, and whiskered auklet the most numerous in the communities—the iAethia pygmaea). Consideration of these shearwaters and some alcids—which feed species as specialists may require revision largely on three prey types, and also include 112 D. G. AINLEY AND G. A. SANGER

Table 13. Use of food resources by seabirds in the Alaska Stream domain. Information is from Tables 1-10. (Trophic level I = plants, II = secondary carnivore, III = tertiary carnivore, IV = upper level carnivore, Sc = scavenger on carrion, offal, or detritus [II-IV]; x = major food in diet, o = minor food, • = incidental food, ? = probable food.)

Habitat, bird trophic levels (I-IV, Sc), and food categories

Oceanic and offshore neritic Inshore neritic

II III IV Sc I III IV Sc

c 01 s '£ -^ sS

u 3 0) u S E" .£5 •« c B 3 J3 "o to 2-3 $ .2 .2 §- .53 ^22 Seabirds U 0. U b b U CQ ft- cj o s Gavia immer G. adamsii G. stellata Podiceps grisegena Diomedea nigripes Fulmarus glacialis Puffinus griseus P. tenuirostris Pterodroma inexpectata Oceanodroma furcata Phalacrocorax auritus P. pelagicus P. urile Philacte canagica Clangula hyemalis Histrionicus histrionicus Polysticta stelleri Somateria mollissima S. spectabilis S. fischeri Melanitta deglandi M. perspicillata M. nigra Mergus serrator Haliaeetus leucocephalus Falco peregrinus Phalaropus fulicarius Lobipes lobatus Stercorarius spp. Larus hyperboreus o o o o o L. glaucescens o o o o o L. argentatus o o o o o L. canus Rissa tridactyla R. brevirostris Sterna paradisaea S. aleutica Uria aalge U. lomvia Lunda cirrhata Fratercula comiculata Cepphus columba Brachyramphus marmoratus B. brevirostris Synthliboramphus antiquus Cyclorrhynchus psittaculus Aethia cristatella A. pusilla A. pygmaea TROPHIC RELATIONS OF SEABIRDS 113

Table 14. Use of food resources by seabirds in the oceanic habitat, central subarctic domain. Information is from Tables 1-10. (Trophic level I = plants, II = secondary carnivore, III = tertiary carnivore, IV = upper level carnivore, Sc = scavenger on carrion, offal, or detritus [II-IV]; X = major food in diet, o = minor food, • = incidental food, ? = probable food.)

Bird trophic levels and food categories

II III IV Sc

a> OS -§ 08 4.9 0) 0) si a O CO CO s 1 u IV CO >> ji J3 2 "o 1 * CO & .h Seabirds o cu o fo fa o PQ

Diomedea nigripes X o o o X X X D. immutabilis X Fulmarus glacialis X o X o X X X Puffinus carneipes o X X P. griseus X X X P. tenuirostris X o X Pterodroma inexpectata X X Oceanodroma furcata X o o o X X X O. leucorhoa X o o o X X X Phalaropus fulicarius X X o Lobipes lobatus X X o Stercorarius spp. o X X ? X Larus hyperboreus X o o X X ? X L. glaucescens X o o X X ? X L. argentatus X o o X X X Rissa tridactyla X X X o Xema sabini X X o Sterna paradisaea X X o Uria aalge X • X X U. lomvia X • X X Lunda cirrhata o X X Fratercula corniculata • X X Cerorhinca monocerata X X Synthliboramphus antiquus X X Cyclorrhynchus psittaculus X o • • Ptychoramphus aleuticus X o

some of the less abundant birds, the marine terparts in the neritic habitat (but see Sanger ducks, which feed mostly on two prey 1973). categories. Another comparison is shown in Table 17, The remaining seabirds are more general in where the species in each community are cate- their feeding. Many have large populations, gorized according to the number feeding at but are not as abundant as shearwaters or each trophic level. If a species feeds at more most alcids. The true "generalists" are the than one level, it is taUied once in each level. species that feed on as many as eight or more Most seabirds (66-77%) feed at the second and types of prey, and relatively few (12%) such third levels as secondary and tertiary carni- species exist in each avian community. These vores. Few feed as terminal carnivores, and birds, the scavengers, include black-footed relatively few are scavengers. Actually, most albatross, fulmar, storm-petrels, and large scavenging occurs at levels II and III, so gulls. The petrels are the scavengers of the about 90% of the seabirds in each community oceanic habitat and the gulls are their coun- feed at levels II and III. Communities includ- 114 D. G. AINLEY AND G. A. SANGER

Table 15. Use offood resources by seabirds in the North American coastal domain. Information is from Tables 1-10. (Trophic level I = plants, II = secondary carnivore, III = tertiary carnivore, IV = upper level carnivore, Sc = scavenger on carrion, offal, or detritus [II-IV]; x = major food in diet, o = minor food, • = incidental food, ? = probable food.)

Habitat, bird trophic levels (I-IV, Sc), and food categories

Oceanic and offshore neritic Inshore neritic

II III IV Sc I — II III IV Sc

Table 16. Number of seabirds of different oceanographic regions having different numbers of categories offood in their diets.

Number of categories in the diets«

Oceanographic region (domain) 1 2 3 4 5-7 7 8 +

Bering Sea coastal 3 11 9 6 5 4 5 Bering Sea 2 6 5 7 5 Alaskan Stream 3 14 14 5 4 4 5 Central Subarctic 1 6 8 4 7 North American Coastal 3 14 17 6 3 4 6 Total 12 51 53 28 12 24 16 Percent total species (196) 6 26 27 14 6 12 8

"These are the "food categories" of Tables 11-15. Items included in diets are not included here.

ing an inshore neritic feeding element are the that the longer species of the two kittiwakes only ones that include herbivores, and even has the shorter bill. Body weight would be a then, few of these species exist in significant better measure of relative size than body size, numbers in the marine environment (discount- but few reliable weight data are available for ing estuaries and sheltered bays). seabirds. It is readily apparent from the foregoing The use of different feeding methods by comparisons that much overlap exists in the species in each community grossly assigns prey eaten by seabirds within each com- birds to feeding at different depths. Thus, munity. The question whether real competi- whereas shearwaters, puffins, and small gulls tion ever exists is academic. Competition per- {JKema sp., Rissa spp.) overlap almost entirely haps exists only rarely because seabirds parti- in prey categories and even prey species, the tion resources through use of different feeding gulls can capture these organisms only at the methods, selection of different-sized prey, and surface; the shearwaters capture them at shal- habitat zonation. Table 18 lists feeding meth- low depths; and the puffins capture them at ods (after Ashmole 1971 and Ainley 1977) and much deeper depths. Direct field observations the body size and bill length of each species of this phenomenon are few but Gould (1971) considered in this review. Bill length is and Sealy (1973a) compared the diets of birds usually related directly to body size (Ashmole feeding in mixed-species flocks. An example of 1968; Bedard 19696), but note, for instance. how even finer divergence in feeding methods

Table 17. Number of species feeding at different trophic levels within seabird communities and habitats of the northeastern North Pacific Ocean and Bering Sea. A single species can be represented in more than one level. (Trophic level I = vegetarian, II = secondary carnivore. III = tertiary carnivore, IV = upper level carnivore, Sc = scavenger [II-IV].)

Oceanic/offshore neritic Inshore neritic

Domain II III IV Sc I II III IV Sc

Bering Sea Coastal 11 17 1? 10 6 23 18 6 6 Bering Sea 22 21 3? 11 — — — — — Alaska Stream 21 19 1? 12 5 28 21 6 6 Central Subarctic 23 22 3? 12 — — — — — North American Coastal 25 24 3? 11 3 28 35 7 10 Total 102 103 11? 56 14 79 74 19 22 Proportion 0.38 0.39 0.02a o.21 0.07 0.38 0.28 0.09 0.10

"Proportion based on the arbitrary assumption that half (5) of the 11 species in question catch and eat birds at sea. 116 D. G. AINLEY AND G. A. SANGER

Table 18. Size relationships and feeding methods of major species in the eastern North Pacific and Bering Sea. (D = dive, SS = surface seize, PP = pursuit plunge, Di = dip, P = plunge, T = tip, X = eats seabirds, A = piracy, SP = shallow plunge.)

Body length^ Bill lengthb Feeding' Species (cm) (mm) method

Gavia adamsii 63.5 90-91 D G. immer 61.0 80-82 D G. arctica 45.7 51-52 D G. stellata 43.5 51-52 D Podiceps grisegena 33.0 48-50 D P. nigricollis 22.9 24-26 D P. auritus 24.1 23-24 D Aechmophorus occidentalis 45.7 65-76 D Diomedea nigripes 71.1 141-144 SS D. immutabilis 71.1 102-112 SS Fulmarus glacialis 45.7 36-37 SS Puffinus cameipes 45.7 41-46 PP P. creatopus 45.7 41-46 PP P. bulleri 38.1 38-45 PP P. griseus 40.3 41-42 PP P. tenuirostris 38.1 31-32 PP Oceanodroma furcata 19.0 15 Di,SS O. leucorhoa 19.0 16 Di,SS Pterodroma inexpectata 29.2 26-27 SS Phalacrocorax auritus 68.6 55-57 D P. penicillatus 73.7 66-71 D P. urile 71.1 54-55 D P. pelagicus 55.9 47-50 D Pelecanus occidentalis 104.0 294-319 P Branta spp. {bemicla) 43.5 33-36 T Philacte canagica 45.7 37-42 T Anas spp. 40.0 32-35 T Clangula hyemalis 38.1 25-27 D Histrionicus histrionicus 30.5 25-28 D Polysticta stelleri 30.5 37-43 D Somateria mollisima 43.5 45-55 D S. spectabilis 40.3 31-33 D S. fischeri 38.1 22-26 D Melanitta deglandi 35.6 41-44 D M. perspicillata 40.3 ca. 40 D M. nigra 35.6 42-47 D Mergus serrator 40.3 45-54 D Haliaeetus leucocephalus 80.0 52-54 X Falco peregrinus 37.5 21-25 z Phalaropus fulicarius 16.5 22 SS Lobipes lobatus 15.2 22 SS Stercorarius pomarinus 43.5 40 SS.A S. parasiticus 40.3 32 SS,A S. longicaudus 38.1 29 SS.A Larus hyperboreus 61.0 55-60 SS L. glaucescens 55.9 54-58 SS L. occidentalis 53.0 54-57 SS.Di L. argentatus 50.8 48-54 SS.Di L. califomicus 43.5 45-50 SS.Di L. heermanni 38.1 42-46 SS.Di L. canus 35.6 34-36 SS.Di TROPHIC RELATIONS OF SEABIRDS 117

Table 18. Continued.

Body length^ BUI length^ Feeding c Species (cm) (mm) method

L. Philadelphia 27.9 30-31 Di Rissa tridactyla 34.2 39-40 Di R. brevirostris 38.1 29-30 Di Xema sabini 27.9 26-27 Di Sterna paradisaea 38.1 31-33 Di,SP S. hirundo/forsteri 35.6 36-39 Di,SP S. aleutica 33.0 33 Di.SP Una aalge 35.6 43-47 D U. lomvia 35.6 39-42 D Lunda cirrhata 31.8 57-60 D Fratercula comiculata 29.2 49-51 D Cerorhinca monocerata 29.2 34-35 D Cepphus columba 26.7 32-33 D Brachyramphus marmoratus 20.3 15 D B. brevirostris 19.0 10 D Synthliboramphus antiquus 20.3 13 D Ptychoramphus aleuticus 17.8 19 D Aethia pygmaea 16.5 8-9 D A. pusilla 13.3 8 D A. cristatella 17.8 11 D Cyclorrhynchus psittaculus 18.4 15 D

a Information on body sizes (length) is from Robbins et al. (1966). ^Information on bill lengths is from Palmer (1962), Dement'ev et al. (1968), and Friedmann (1950). •^Feeding methods are from Ashmole (1971) as adapted by Ainley (unpubl. manuscr.).

helps to partition food resources has been pro- these gulls were as much generalists in the vided by Spring (1971) in his comparison of oceanic habitat as they are in the neritic. In- the two murres. Both species feed by diving to terestingly, their bill and body sizes fall be- great depths, but the thick-billed murre is tween those of the albatross and the fulmar, able to hover over the bottom and thereby is thus in theory enabUng them to invade the better able to capture benthic organisms. oceanic habitat without great competition. It The scavengers (generalists) offer a good is Ukely that their invasion occurred during example of how a range of bird and bill sizes is historical times and is related to their habit of usually represented among species having following fishing boats from shore out to sea similar diets and feeding methods. The pro- (Sanger 1973). If so, the gulls might be assum- gression of oceanic scavenger sizes is graded ing from other species part of a previously un- rather evenly from the black-footed albatross contested resource. down to the northern fulmar, to the scaled Another interesting group of species that petrel, to the storm-petrel. All these species shows close similarities in diet consists of the capture prey that occur only at or near the piscivorous loons, grebes, and mergansers. water surface. Recently Sanger (1973) re- All these birds, including seven or eight ported appreciable numbers of glaucous- species, apparently feed on fish occurring on winged gulls (Larus glaucescens) and herring or near the bottom in the inshore neritic habi- gulls (L. argentatus), noted neritic scaven- tat. Again, however, an even progression in gers, out in the oceanic realm of the petrel. He size exists: yellow-billed loon (Gavia adamsii), presented limited data that suggested an common loon {G. immer), arctic loon (G. arc- overlap between the diet of these gulls and tica), red-throated loon (G. stellata), western that of black-footed albatrosses, as noted by grebe (Aechmophorus occidentalis), red- Miller (1940). It would not be surprising if necked grebe (Podiceps grisegena), and com- 118 D. G. AINLEY AND G. A. SANGER

mon merganser (Mergus merganser). Most ing and pursuit plunging. These birds are likely then, they select different-sized fish. mostly absent from tropical and subtropical Another example of this phenomenon is pro- conmiunities because feeding by these meth- vided by the eight neritic gulls, which are ods is not adaptive there (Ainley 1977). largely scavengers and show a remarkably Hence, oil pollution has all the potential of even progression in bill and body size. Finally, rendering maladaptive the principal feeding as shown clearly by Bedard (1969a, 19696) methods of many polar seabirds. and Harris (1970), alcids of different sizes Another way in which seabird feeding re- prey, often of the select different-sized same lates to conservation problems concerns com- species. petition between birds and man for commer- final important way in which seabirds A cially valuable fishes. A related problem is the partition available resources is by inhabiting mass mortality of seabirds due to man's fish- different zones. Zonation is especially evident ing gear. An acute situation is the drowning during the breeding season when species com- of seabirds caught in salmon gill nets (Barto- mon to the same breeding site sort themselves nek et al. 1974; Pacific Seabird Group 1975; out according to the distances they range for Ripley 1975; King et al., this volume). Imme- food. This phenomenon was discussed by diate action is definitely required. Murphy (1936), Shuntov (1974), Sealy (1972), Further, competition between birds and Cody (1973), and Scott (1973). man for the same resource has the potential for disastrous effects on bird populations if humans out-compete the birds and overfish Trophic Relations and the resource. A classic example, reviewed by Seabird Conservation Idyll (1973), is the possible collapse of the Peruvian anchovy (Engraulis ringens) fishery;

if overfishing and an El Nino should coincide, The species that appear to have specialized the Peruvian seabird populations could col- food habits (if further research confirms that lapse as well. The California fisheries and ap- indeed they do) are probably very sensitive to parently the double-crested cormorants that vagaries in food availability or are, at least, nest on the Farallon Islands have both suf- much more sensitive than other species. Some fered from the demise of the Pacific sardine speciaUsts which also have very restricted dis- (Sardinops caerula) in the California current tributions would, therefore, be susceptible to (Ainley and Lewis 1974). In regulating fish localized catastrophes occurring where harvests, fishery organizations should include speciaUsts are concentrated around the food in their calculations the harvest by creatures resource. This is proved in the case of the other than (Schaefer rather than scoters, which are both specialized and rather man 1970), evading the issue by referring to a vague restricted to nearshore beds of molluscs and "natural mortaUty." have fallen victim to local oil slicks (Small et al. 1972). An example of another poten- Finally, fishing by humans can benefit sea- tially critical situation is that of the black birds by removing fish (or whales) that com- brant, which at certain times of the year con- pete with birds for food (Laws 1977). A poten- centrate their entire population around eel- tial example is that of northern California, grass beds in Bristol Bay, Alaska, where where salmon and seabirds both feed heavily much offshore oil driUing may soon occur. on juvenile rockfishes (Fitch and Lavenberg Birds adapted to feed by diving, with the 1971; Point Reyes Bird Observatory, unpub- exception of cormorants, spend most of their lished data). Harvest of salmon should theo- time in the water. These species are therefore retically leave more rockfish available for most susceptible to oiling (Small et al. 1972), birds to eat. This sort of situation has not yet but pursuit plungers (the shearwaters) are been fully documented and definitely war- also highly susceptible (Point Reyes Bird Ob- rants further study, especially in such areas servatory, unpubUshed data). A characteristic as the Bering Sea, where some fish stocks of polar and subpolar seabird communities is have become depressed due to overfishing the high percentage of birds that feed by div- (Gulland 1970). TROPHIC RELATIONS OF SEABIRDS 119

Recommendations for tions of higher vertebrates off Uruguay, in- Further Research cluding dolphins, pinnipeds, seabirds, and some large fish. In a review study, Sanger (1974) considered the food-chain relations of Many people realize intuitively that sea- similar vertebrates in the Bering Sea. These birds are important members of marine eco- sorts of studies will serve to bring the role of systems. Although the supporting evidence is seabirds into perspective with other upper not now available, it will be needed if seabirds trophic level feeders. are to be protected. Emotion alone will not justify the protection of seabirds in an age when the human race moves steadily toward Acknowledgments global famine. The job at hand is, in part, to sell seabirds, not just to the public, govern- We much appreciate the opportunity to par- ment officials, executives of oil companies, or ticipate in the symposium at which this paper fish-packing concerns, but also to marine was presented. The encouragement and help biologists and oceanographers, for the scien- given by J. C. Bartonek was indispensable. tists have the best means to study organisms D. G. Ainley's participation in the sym- at sea. We must move away from the concept posium was supported by the Point Reyes that seabirds are merely yo-yos of various Bird Observatory. This is contribution No. sizes, shapes, and colors on strings of various 124 of the Point Reyes Bird Observatory. lengths that venture forth to sea from the land, grab a quick lunch, and then return to the safety of terra firma. Seabirds are marine References organisms and deserve at least as much research attention as that currently given Ainley, D. G. 1977. Feeding methods of seabirds: a marine manmials. comparison of polar and tropical communities. The information now available on seabird Pages 669-685 in G. A. Llano, ed. Adaptations in diets is largely presented in terms of the num- Antarctic ecosystems. Gulf Publishing Co., ber and volume of various prey species taken. Houston, Texas. Whereas these data provide the relative im- Ainley, D. G., and T. J. Lewis. 1974. The history of Farallon Island marine bird populations, 1854- portance of prey, fishery data on prey stocks 1972. Condor 76:432-446. are usually measured in terms of biomass. Ashmole, N. P. 1968. Body size, prey size and eco- Thus, it is difficult to relate seabird data to logical segregation in five sympatric tropical the immense wealth of information on biologi- terns (Aves; Laridae). Syst. Zool. 17:292-304. cal oceanography. If we are to recognize the Ashmole, N. P. 1971. Sea bird ecology and the importance of seabirds in the nutrient and marine environment. Pages 223-286 in D. S. energy cycling of marine ecosystems, rather Earner and J. R. King, eds. Avian Biology, Vol. 1. than considering them merely as "yo-yo Academic Press, N. Y. predators," we must relate them to the total Ashmole, N. P., and M. J. Ashmole. 1967. Compara- marine community. tive feeding ecology of sea birds of a tropical oceanic island. Peabody Mas. Nat. Hist., Yale The goal of marine ornithologists should be Univ., BuU. 24:1-131. to refine and broaden considerably in detail Bailey, A. 1922. Notes on the yellow-billed loon. such studies as those by Sanger (1972), Shun- Condor 24:204-205. tov (1974), and Laws (1977), who attempted to Bailey, A. 1927. Notes on the birds of southeastern assess the relations between seabird popula- Alaska. Auk 44:1-23. tions and stocks of other marine organisms Banner, A. H. 1954. New records of Mysidacea and Euphausiacea from the northeastern Pacific and for the northern North Pacific, the world adjacent areas. Pac. Sci. 8:125-139. oceans, and the Antarctic, respectively. The Bartonek, J. C, R. Eisner, and E. H. Fay. 1974. trophic roles played by seabirds must be Mammals and birds. Pages 23-28 in E. J. Kelly year- studied in detail at the community level and D. W. Hood, eds. Probes: a prospectus on round before those analyses can be properly processes and resources of the Bearing Sea shelf. refined. Another exemplary work is that done Inst. Mar. Sci., Univ. Alaska, Fairbanks, Publ. by Brownell (1974), who studied trophic rela- Inf. BuU. 74-1. 120 D. G. AINLEY AND G. A. SANGER

Bartonek, J. C, and D. D. Gibson. 1972. Summer region. Int. North Pac. Fish. Comm. Bull. 13. distribution of pelagic birds in Bristol Bay, 195 pp. Alaska. Condor 74:416-422. Drent, R. H. 1965. Breeding biology of the pigeon Bartsch, P. 1922. A visit to Midway Island. Auk guillemot, Cepphus columba. Ardea 53:99-160. 39:481-488. Dunbar, M. J. 1946. On Themisto libellula in Baffin Bedard, J. 1969a. Feeding of the least, crested, and Island coastal waters. J. Fish. Res. Board Can. parakeet auklets around St. Lawrence Island, 6:419-434.

Alaska. Can. J. Zool. 47:1025-1050. Einarrson, H. 1945. Euphausiacea. I. North At- Bedard, J. 19696. Adaptive radiation in Alcidae. lantic species. Dana-Rep. Carlsberg Found. 27. Ibis 111:189-198. 185 pp. Belopol'skii, L. 0. 1961. Ecology of sea colony birds Falla, R. A. 1934. The distribution and breeding of the Barents Sea. (Transl. from Russian.) Israel habits of petrels in northern New Zealand. Rec. Program for Scientific Translations, Jerusalem. Aukl. Inst. Mus. 1:245-260. 346 pp. Favorite, F., A. J. Dodimead, and K. Nasu. 1976. Bent, A. C. 1921. Life histories of North American Oceanography of the subarctic Pacific region, gulls and terns. U. S. Natl. Mus. Bull. 113. 1960-71. Int. North Pac. Fish. Comm. Bull. 33:1- 345 pp. 187. Bent, A. C. 1922. Life histories of North American Fay, F. H., and T. J. Cade. 1959. An ecological petrels and peUcans and their allies. U. S. Natl. analysis of the avifauna of St. Lawrence Island, Mus. Bull. 121. 343 pp. Alaska. Univ. Cahf. Publ. Zool. 63:73-150. Bent, A. C. 1925. Life histories of North American Fisher, J. 1952. The fuhnar. Collins, London. 496 pp. wUd fowl. U. S. Natl. Mus. BuU. 130. 311 pp. Fisher, W. K. 1904. On the habits of the Laysan Bent, A. C. 1946. Life histories of North American albatross. Auk 21:8-19. diving birds. (Reprint of U. S. Natl. Mus. Bull. Fitch, J. E., and R. J. Lavenberg. 1971. Marine food 107.) Dodd, Mead and Co., N. Y. 237 pp. and game fishes of California. Univ. CaUf. Press, Brownell, R. L., Jr. 1974. Feeding ecology of the Berkeley. 179 pp. Franciscana Dolphin, Pontoporia blainvillei, and FoUett, W. I., and D. G. Ainley. 1976. Fishes col- associated top trophic vertebrates in Uruguayan lected by pigeon guillemots, Cepphus columba waters. Ph.D. Thesis. Univ. Tokyo, Tokyo, Pallas, nesting on Southeast Farallon Island, Japan. CaUfornia. CaUf. Fish Game 62:28-31. Chatwin, S. L. 1956. The western grebe taken on Friedmann, H. 1950. Birds of North and middle hook and line. Condor 58:73-74. America. Part XI. U. S. Natl. Mus. BuU. 50. Cleaver, F. C, and D. M. Franett. 1945. The preda- 793 pp. tion by seabirds upon the eggs of the Pacific Gabrielson, I. N., and S. G. Jewett. 1940. Birds of herring {Clupea pallasii) at Holmes Harbor dur- Oregon. Oregon State College, Corvallis. 650 pp. ing 1945. State of Washington, Department of Gabrielson, I. N., and F. C. Lincoln. 1959. Birds of Fisheries, Biological Report 46B. 18 pp. Alaska. Stackpole Co., Harrisburg, Pennsyl- vania. 922 pp. Cody, M. L. 1973. Coexistence, coevolution and con- Gould, P. J. 1971. Interactions of seabirds over the vergent evolution in seabird communities. Ecol- open ocean. Ph.D. Thesis. Univ. of Arizona, ogy 54:31-44. Tucson. 110 Cottam, C. 1939. Food habits of North American pp. Grinnell, J. 1897. Notes on the marbled murrelet. diving ducks. U. S. Dep. Agric, Tech. Bull. 643. Osprey 1:115-117. 140 pp. Grinnell, J. 1899. The rhinoceros auklet at Catalina Cottam, C, and P. Knappen. 1939. Food of some Island. Bull. Cooper Ornithol. Club 1:87-88. uncommon North American birds. Auk 56:138- Gulland, J. A. 1970. fish resources of the ocean. 169. The FAO, Rome. 255 pp. Craddock, D. R., and R. D. Carlson. 1970. Peregrine Hamilton, W. J. 1958. Pelagic birds observed on a falcon observed feeding far at sea. Condor 72:375- north Pacific crossing. Condor 60:159-164. 376. Harris, M. P. 1965. The food of some Larus gulls. Dement'ev, G. P., R. N. Meklenburtsev, A. M. Sudi- Ibis 107:43-53. lovskaya, and E. P. Sangenberg. 1968. Birds of Harris, M. P. 1970. Differences in the diet of British the Soviet Union. Vol. 2. (Transl. from Russian.) auks. Ibis 112:540-541. Israel Program for Scientific Translations, Jeru- Hart, J. L. 1973. Pacific fishes of Canada. Fish. Res. salem. 553 pp. Board Can. Bull. 180. 740 pp. Divoky, G. J. 1976. The pelagic feeding habits of Hartley, C. H., and J. Fisher. 1936. The marine the Ivory and Ross' gulls. Condor 78:85-90. foods of birds in an inland fjord region of West Dodimead, A. J., F. Favorite, and T. Hirano. 1963. Spitsbergen. Part 2. Birds. J. Anim. Ecol. 5:370- Review of oceanography of the subarctic Pacific 389. TROPHIC RELATIONS OF SEABIRDS 121

Heath, H. 1915. Birds observed on Forrester Is- Martin, P. W., and M. T. Myers. 1969. Observations land, Alaska, during the summer of 1913. Condor on the distribution and migration of some sea- 17:20-41. birds off the outer coasts of British Columbia and Hubbs, C. L., A. L. Kelly, and C. Limbaugh. 1970. Washington State, 1946-1949. Syesis 2:241-256. Diversity in feeding by Brandt's cormorant near McGilvrey, E. B. 1967. Food habits of sea ducks San Diego. Calif. Fish Game 53:156-165. from the northeastern United States. Pages 142- Idyll, C. P. 1973. The anchovy crisis. Sci. Am. 145 in Wildfowl Trust 18th annual report. 228:22-29. Miller, L. 1936. Some maritime birds observed off Imber, M. J. 1973. The food of grey-faced petrels San Diego, California. Condor 38:9-16. (Pterodroma macroptera gouldi Hutton), with Miller, L. 1940. Observations on the black-footed special reference to diurnal migration of their albatross. Condor 42:229-238. prey. J. Anim. Ecol. 42:645-662. Munro, J. A. 1941. Studies of waterfowl in British Ingolfsson, A. 1967. The feeding ecology of five Columbia: the grebes. B. C. Prov. Mus. Occas. species of large gulls (Larus) in Iceland. Ph.D. Pap. 3. 71 pp. Thesis. Univ. of Michigan, Ann Arbor. 186 pp. Munro, J. A., and W. A. Clemens. 1931. Waterfowl Jewett, S. G., W. P. Taylor, W. T. Shaw, and J. W. in relation to the spawning of herring in British Aldrich. 1953. Birds of Washington State. Univ. Columbia. Biol. Board Can. Bull. 17. 46 pp. of Washington Press, Seattle. 767 pp. Munro, J. A., and W. A. Clemens. 1939. The food KoeUnk, A. F. 1972. Bioenergetics of growth in the and feeding habits of the red-breasted merganser pigeon guillemot, Cepphus columba. M. S. Thesis. in British Columbia. J. Wildl. Manage. 3:46-53. Univ. of British Columbia, Vancouver, Canada. Murphy, R. C. 1936. Oceanic birds of South 71pp. America, Vol. 2. Macmillan, N. Y. 604 pp. Komaki, Y. 1967. On the surface swarming of Ogi, H., and T. Tsujita. 1973. Preliminary examina- euphausiid crustaceans. Pac. Sci. 21:433-448. tion of stomach contents of murres {Una spp.) from the eastern Bering Sea and Bristol Bay, Kooyman, G. L. 1974. Behaviour and physiology of June-August, 1970 and 1971. Jpn. J. Ecol. diving. Pages 115-138 in B. Stonehouse, ed. The 23:201-209. biology of penguins. Macmillan, London. Oliver, W. R. B. 1955. New Zealand birds, 2nd ed. Kortright, F. H. 1942. The ducks, geese and swans A. H. and A. W. Reed, Wellington, New Zealand. of North America. Wildlife Management Insti- Pacific Seabird Group. 1975. Policy statement: Inci- tute, Washington, D. C, and Stackpole Co., dental seabird kills from salmon gillnet fisheries. Harrisburg, Pennsylvania. 476 pp. Pac. Seabird Group Bull. 2:19-20. Kozlova, E. V. 1961. Fauna of the U.S.S.R., Birds: Alcae. (Transl. from Russian.) Israel Program for Palmer, R. S. 1962. Handbook of North American Scientific Translations, Jerusalem. 140 pp. birds. Vol. 1. Yale Univ. Press, New Haven, Connecticut. Kuroda, N. 1954. On the classification and Pearson, T. phylogeny of the order Tubinares, particularly H. 1968. The feeding biology of sea bird species breeding the shearwaters (Puffinus). Herald Co., Tokyo. on the Fame Islands, Northum- 179 pp. berland. J. Anim. Ecol. 37:521-551. Kuroda, N. 1955. Observations on pelagic birds of Perthon, P. 1968. Food and feeding habits of the the Northwest Pacific. Condor 57:290-300. common eider {Somateria mollissima). Nytt. Mag. Zool. 15:97-111. Laws, R. M. 1977. The significance of vertebrates in the Antarctic marine ecosystem. Pages 411-438 Phillips, R. E., and G. D. Carter. 1957. Winter food in G. A. Llano, ed. Adaptations in Antarctic eco- of western grebes. Murrelet 38:5-6. systems. Gulf Publishing Co., Houston, Texas. Preble, E. A., and W. L. McAtee. 1923. A biological Linton, C. B. 1908. Notes from Santa Cruz Island. survey of the Pribilof Islands, Alaska. U. S. Bur. Condor 10:124. Biol. Surv. N. Am. Fauna 46. 255 pp. Mabbot, D. C. 1920. Food habits of seven species of Richardson, F. 1961. Breeding biology of the rhi- American shoal-water ducks. U. S. Dep. Agric, noceros auklet on Protection Island, Washington. Bull. 862. 68 pp. Condor 63:456-473. Madsen, F. J. 1957. On the food habits of some fish- eating birds in Denmark. Dan. Rev. Game Biol. Ripley, S. D. 1975. The view from the castle. Smith- 3(2):19-83. sonian 6:6. Robbins, C. S., B. Brunn, H. Manuwal, D. A. 1974. The natural history of Cas- and S. Zim. 1966. Birds of North America. Golden Press, N. Y. 340 sin's auklet (Ptychoramphus aleuticus). Condor pp. 76:421-431. Roberts, A. A., and E. H. Huntington. 1959. Food Martin, P. W. 1942. Notes on some pelagic birds off habits of the merganser in New Mexico. N. M. the coast of British Columbia. Condor 44:27-29. Dep. Fish Game, Bull. 9. 36 pp. 122 D. G. AINLEY AND G. A. SANGER

Robertson, I. 1974. The food of nesting double- Small, J., D. G. Ainley, and H. Strong. 1972. Notes crested and pelagic cormorants at Mandarte Is- on birds killed in the 1971 San Francisco oil spill. land, British Columbia, with notes on feeding Calif. Birds 3:25-32. ecology. Condor 76:346-348. Spaans, A. L. 1971. On the feeding ecology of the

Robertson, I. 1972. Studies on fish-eating birds and herring gull Larus argentatus Pont, in the north- their influence on stocks of the Pacific herring, ern part of the Netherlands. Ardea 59:73-188. Clupea harengus, in the Gulf Islands of British Columbia. Herring Investigations, Pac. Biol. Spring, L. 1971. A comparison of functional and morphological adaptations in the Stn., Naimo, B.C. 28 pp. (Unpublished report) common murre Sanger, G. A. 1972. Preliminary standing stock and (Uria aalge) and thick-billed murre (Uria lomuia). biomass estimates of seabirds in the subarctic Condor 73:1-27. Pacific region. Pages 589-611 in A. Y. Takenouti Stejneger, L. 1885. Results of ornithological ex- plorations in the Islands et al., eds. Biological oceanography of the north- Commander and Kam- ern north Pacific Ocean. Idemitsu Shoten, Tokyo. chatka. U. S. Natl. Mus. Bull. 29:7-362. 626 pp. Sverdrup, H. V., M. W. Johnson, and R. H. Sanger, G. A. 1973. Pelagic records of glaucous- Fleming. 1942. The oceans: their physics, winged and herring gulls in the north Pacific chemistry and general biology. Prentice-Hall, Ocean. Auk 90:384-393. Englewood CUffs, N. J. 1087 Sanger, G. A. 1974. A preliminary look at marine pp. Swartz, L. G. 1966. Sea-cliff birds. Pages 611-678 in mammal food-chain relationships in Alaskan N. J. Wilimovsky and J. N. Wolfe, eds. Environ- waters. U. S. Natl. Mar. Fish. Serv., Mar. Mam- ment of the Cape Thompson region, Alaska. U. S. mal Div., Seattle. 29 pp. (Unpublished report) Commission, Div. Tech. Inf., Oak Schaefer, M. S. 1970. Men, birds and anchovies in Atomic Energy the Peru current—dynamic interactions. Trans. Ridge, Tennessee. 1250 pp. Am. Fish. Soc. 99:461-467. Thoresen, A. C, and E. S. Booth. 1958. Breeding ac- Scott, J. M. 1973. Resource allocation in four tivities of the pigeon guillemot, Cepphus columba synoptic species of marine diving birds. Ph.D. columba (Pallas). Dep. Biol. Sci., Walla Walla Col- Thesis. Oregon State Univ., Corvallis. 97 pp. lege, Washington, Publ. 23. 34 pp. Scott, J. M., J. Butler, W. G. Pearcy, and G. A. Tuck, L. M., and H. J. Squires. 1955. Food and feed- of the Bertrand. 1971. Occurrence Xantus' murre- ing habits of Brunnich's murre {Uria lomuia lom- let off the Oregon coast. Condor 73:254. uia) on Akpatok Island. J. Fish. Res. Board Can. Sealy, S. G. 1972. Adaptive differences in breeding 12:781-792. biology in the marine bird family Alcidae. Ph.D.

Thesis. Univ. of Michigan, Ann Arbor. 283 pp. Uspenski, S. M. 1958. The bird bazaars of Novaya Sealy, S. G. 1973a. Interspecific feeding assem- Zemlya. (Transl. from Russian.) Transl. by De- blages of marine birds off British Columbia. Auk partment of Northern Affairs and Natural Re- 90:796-802. sources, Canada. 159 pp. Sealy, S. G. 19736. Breeding biology of the horned Ward, J. G. 1973. Reproductive success, food puffin on St. Lawrence Island, Bering Sea, with supply, and the evolution of clutch-size in the zoogeographical notes on the North Pacific glaucous-winged gull. Ph.D. Thesis. Univ. of puffins. 27:99-119. Pac. Sci. British Columbia, Vancouver, Canada. 119 pp. Sealy, S. G. 1975. Feeding ecology of the ancient and marbled murrelets near Langara Island, Wetmore, A. 1924. Food and economic relations of British Columbia. Can. J. Zool. 53:418-433. North American grebes. U. S. Dep. Agric, Bull. Serventy, D. L., V. Serventy, and J. Warham. 1971. 1196.23 pp. The handbook of Australian sea birds. A. H. and White, C. M., W. B. Emison, and F. S. L. WiUiam- A. W. Reed, Wellington, New Zealand. 254 pp. son. 1971. Dynamics of raptor predation on Am- Sheard, K. 1953. Taxonomy, distribution and de- chitka Island, Alaska. Bioscience 21:623-627. velopment of the Euphausiacea (Crustacea). Rep. White, C. M., W. B. Emison, and F. S. L. William- B.A.N.Z. Antarct. Res. Exped., Ser. B (Zoology son. 1973. DDE in a resident Aleutian Island and Botany), 8:1-72. peregrine population. Condor 75:306-311. Shuntov, V. P. 1972. Sea birds and the biological structure of the ocean. (Transl. from Russian.) Zelikman, E. A. 1961. The behavior pattern of the Bur. Sport Fish. Wildl. and Natl. Sci. Found., Barents Sea Euphausiacea and possible causes of Washington, D. C. Nat. Tech. Inf. Serv. TT 74- seasonal vertical migrations. Int. Rev. Ges. 55032. 566 pp. Hydrobiol. Hydrogr. 46:276-281. Population Dynamics in Northern Marine Birds

William H. Drury College of the Atlantic Bar Harbor, Maine 04609

Abstract

It seems only reasonable to assume that populations of marine birds fluctuate even when not disturbed by man; such fluctuations would result both from the secondary effects of species adaptive tactics and from changes in the marine environment. I briefly review some human activities and some other natural processes that have resulted in changes in numbers and distribution of seabirds and present a short discussion of theoretical models which emphasizes that conclusions drawn or predictions made from models of the dynamics of populations depend upon the assumptions about stability that were used in preparing the models. I then review those special characteristics of seabirds which are directly relevant to planning programs intended to protect seabirds or encourage their increase and identify several goals for improving our understanding of the population dynamics and biology of marine birds. My general conclusion is that enough is already known to undertake effective conservation programs, and that time is pressing.

Seabirds have been categorized as renew- changeably for those bird species which de- able resources in only a few places, although pend upon salt water for some part of their an- their symbolic value has been recognized for nual cycle (c.f., the Pacific Seabird Group). centuries (for example, the medieval poem "The Seafarer" and the designs on Saint Population Fluctuations Cuthbert's tunic). With the exception of the Russians (Belopol'skii 1961; Uspenski 1956), Broadly stated, the populations of northern the Australians (Serventy 1967), and the Ice- seabirds have shown marked short- and long- landers, industrialized peoples have not con- term fluctuations. Most authors have as- sidered seabirds to be salable and therefore sumed that all such fluctuations reflect worth managing. Yet during many centuries human disturbance of the natural system, be- the seabirds of the northern seas were a major cause of the obvious effects of human preda- food for coastal and island villages (Bent tion during the last 200 years. 1919, 1921, 1922; Fisher and Lockley 1954). Some biological principles that affect the dynamics of seabird populations are identified Human Impact in this paper. I believe these principles must form the basis of plans to maintain and in- In the centuries before people traveled ex- crease seabird numbers. tensively between islands, seabirds were I describe some observations of population taken in ways that we judge must have changes, review briefly the conflicting theo- allowed the survival of the colonies (e.g., those retical frameworks for population dynamics, at the Faroes or Saint Kilda, those in Iceland and identify some of the biological character- and Greenland, or those in the Aleutian Is- istics of marine birds that affect the way in lands and the Bering Strait). We presume which population changes occur. The terms either that the populations of island peoples "seabirds" and "marine birds" are used inter- were regulated by shortage of resources other

123 124 W. H. DRURY

than seabirds or that those who overcropped Positive Effects and eliminated the seabirds suffered the There can be Uttle doubt that human activi- consequences. ties have also had marked positive effects in some cases. For example, Fisher (1952) sug- Negative Effects gested that the North Atlantic fulmar {Ful- marus glacialis) was provided food first by When a sea-going, commodity-oriented way whaling, then by commercial fishing, and that of Ufe evolved, seabirds were killed in huge this food allowed the species to increase numbers for such uses as the plumage trade, steadily over the last 3 centuries. fish bait, or rendering into oil (Tuck 1960; The worldwide increase of gulls (Larus Fisher and Lockley 1954). Even the eUmina- argentatus, L. fuscus, L. dominicanus, L. ridi- tion of several colonies— Funk Island, e.g., bundus, L. novae-hollandii) has been credited Newfoundland (Tuck 1960); Seal Island, East- to availability of food from wasteful human ern Egg Rock, Maine (Norton 1921); Muske- garbage disposal (Murray and Garrick 1964; get, Massachusetts (Forbush 1929)— may Fordham 1968, 1970; Harris 1964; Harris and have had little effect on the rate of cropping Plumb 1965; Kadlec and Drury 1968; Brown because those who killed off one source could 1967; Mills 1973; Vermeer 1963). probably seek out another. As the colonial It is hard to dismiss the evidence pointing seabirds became scarce they became more to the impact of human activities on seabird valuable, which stimulated more intensive populations during the last 3 centuries. Yet it pursuit of the remnants (Dutcher 1901, 1904). would be misleading to assume that without In some places where seabird colonies did man's interference seabird populations would not supply a croppable economic resource, the have remained stable. Success in designing islands were used for alternative crops with at programs of protection and population en- least temporary commodity value (e.g., foxes hancement must allow for the reahties—that were introduced in the Aleutian Islands; Bent seabird populations fluctuate inherently, and 1919). Large herbivores were introduced to that secular changes occur regularly in their supply meat for island residents (e.g.. Saint environment. Matthew Island; Klein 1959), as well as pigs, cattle, sheep, goats, and rabbits on islands in the North Atlantic and southern oceans (many authors). Increases in many seabird Impact ofNatural Events populations over the last 75 years have been population changes appear to result generally associated with relief from preda- Some other are tion by humans such as the fowlers, eggers, from sudden impacts; changes and plume hunters of the 19th century. Such gradual. relief may have been partly responsible for the Sudden Disasters increase of North Atlantic gannets, Sula bassana, and common murres or guillemots, Uria Gromme (1927) reported windrows of dead aalge (Fisher and Vevers 1943, 1944; Cramp murres in the Unimak Pass and Alaska Penin- et al. 1974). On a smaller scale, several popula- sula; die-offs of murres in winter storms in the tion increases along the coast of New England Atlantic and Arctic Oceans were reported by have been recorded following the enactment Tuck (1960) and Dement'ev et al. (1968). of protective legislation (Dutcher 1901, 1904; Recently some mass mortalities have been Norton 1921, 1924; Palmer 1949; Drury 1973). associated with specific causes. Bailey and Coulson (1974) argued that in addition to re- Davenport (1972) reported that starvation lief from predation, the explosion of the popu- caused the die-off of common murres in the lation of kittiwakes {Rissa tridactyla) in this southern Bering Sea-Bristol Bay area. Foul century resulted from access to previously un- weather, which apparently inhibited feeding occupiable breeding sites. Nesting cUffs and between 19 and 23 April 1970, culminated in buildings suitable for kittiwake nesting are an intense storm. Similarly in late winter 1969 abundant and now protected from egging or bad weather in the Irish Sea, combined with fowUng. strains of molt and perhaps contamination POPULATION DYNAMICS IN NORTHERN MARINE BIRDS 125

with industrial chemicals, seems to have con- changes in relatively constant habitats are tributed to mass mortality of the same probably those available in the British Trust species (called common guillemot in Britain; for Ornithology's breeding censuses of song- Holdgate 1971). The seabird victims of this birds. Songbirds are short-lived and their event had metabolized their body fat and as a populations change on relatively short time result, polychlorinated biphenyls (PCB) and scales. The northwestern European landscape other industrial chemicals passed into livers, has remained relatively constant for the last kidneys, and brains. Again, a storm at the end 75 years, yet there are observable decade-long of a period of stress seems to have been more trends—for example, of willow warblers (Phyl- than the birds could tolerate. loscopus trochilus) and dunnock {Prunella A further example of a die-off of waterfowl modularis). There are detailed data on popula- apparently brought on by starvation was tion changes in great tits (Parus major) given by Barry (1968), who estimated that through the work of Kluyver (1951), Lack about 100,000 king eiders (Somateria spec- (1964), and Perrins (1965). tabilis) died when they arrived before the ice broke up in the Beaufort Sea in spring 1964. Effects Reflecting Diseases have produced massive die-offs in Environmental Change marine birds. Fowl cholera caused high mor- Nelson (1966) argued that the increase of tality in nesting common eiders (Somateria gannets in the North Atlantic during this cen- mollissima) in the Gulf of St. Lawrence in tury has been related to increasing tempera- Quebec (Reed and Cousineau 1967) and in tures rather than (as usually ascribed) to in- Penobscot Bay, Maine, in the early 1960's creased food from fish damaged or escaped (H. Mendall, personal communication). during commercial fishing. Poisoning from a "red tide" (a bloom of the Ainley and Lewis (1974) described a particu- dinoflagellate Gonyaulax tamerensis, caused larly interesting example of the effects of en- a die-off of black ducks [Anas rubripes) and vironmental change on seabird populations. herring gulls on the coast of New England in The events begin with the decrease of sea- 1972. Similarly a die-off of shags {Phalacro- birds on the Farallon Islands off California as corax aristotelis) on the east coast of England a result of human depredations. Even after was caused by a "red tide" (Coulson et al. fowling was made illegal, the populations of 1968). During a period of 1 week 90% of the murres, double-crested cormorants (Phalacro- shag nests on the Fame Islands in North- corax auritus), and especially of tufted puffins umberland were deserted and about 80% of (Lunda cirrhata) and pigeon guillemots con- the breeding population died. tinued to decline as a result of oil pollution. During the last 3 decades the smaller species of seabirds nesting on the Farallons, such as Gradual Declines rhinoceros auklets (Cerorhinca monocerata), When the new volcanic island of Bogoslov have increased rapidly and the authors sug- emerged in the western Aleutians, Preble and gest that their increase was abetted by an in- McAtee (1923) reported that it was colonized crease in the small prey fish, northern an- by large numbers of pigeon guillemots chovy (Engraulis mordax). One of course ex- {Cepphus columba), but in the following pects predators to be affected by changes in decades the guillemots have steadily de- the abundance of their prey. During this same creased (G. J. Divoky, personal communica- period, larger species of seabirds such as tion). As a further example, the nesting popu- double-crested cormorants and tufted puffins lation of Atlantic puffins (Fratercula arctica) have failed to recover their numbers, and the in the Atlantic has declined over the past authors speculate that this failure is related several years, especially those nesting on the to a decrease of the larger prey fish, Pacific Outer Hebrides (Flegg 1972; Harris 1976). sardine (Sardinops caerulea). It is difficult to find seabird species whose A widely publicized impact of environ- nesting grounds have not been affected by mental fluctuation upon seabird populations humans but whose numbers have been cen- is that of the northeast wind. El Nino, off the sused. The best illustrations of secular Peruvian coast. This wind pushes the upwell- 126 W. H. DRURY

ing Humboldt Current water offshore and maximum rate of production of new indi- causes mass mortality in the Peruvian an- viduals (or maximum sustained yield). These chovies (Engraulis ringens) and, as a conse- assumptions have supplied the theoretical quence, a die-off among the millions of sea- framework for virtually all game management birds such as Peruvian guanay cormorants and many fisheries practices. (Phalacrocorax bougainvillii) and Peruvian Once stability was assumed, a mechanism boobies or piquero (Sula variegata) which feed for maintaining stability was necessary. This upon them (Murphy 1936) mechanism was found in an interaction between the population and the environment, called density-dependent mortality (Nichol- Theoretical son 1933). The impact of this feedback has been assumed to cause the point of inflection Considerations of the "sigmoid curve" and to regulate the density "at equilibrium." Can useful generalizations be drawn from Populations growing in relatively isolated these observations on population changes? or closed systems have been observed to fol- Can a model be constructed of the forces low a sigmoid curve toward a steady state. which drive population changes or of popula- have data on the growth of several Massa- tion-habitat interactions which keep popula- We chusetts gull colonies which show this type of tions from extinction? Some conflicting theo- short-period rapid increase followed by a long ries and assumptions of population dynamics sequence of shallow oscillations (Drury and are examined and discussed below. Nisbet 1972), But usually observations have been terminated at about the time the popula- The Assumption ofPopulation tion passed through the point of inflection. Stability and of Closely Attuned • Lack (1954) accepted the principles formu- Density-dependent Mortality lated by Lotka-Volterra and hence viewed Nicholson's (1933) density-dependence as logi- During the 5 decades before 1970, it was cally necessary. Lack (1948, 1954) argued that widely accepted that most animal populations reproductive effort (clutch size or litter size were generally stable and saturated before the times the number of broods) must be as large arrival of the white man. Although a few field as the parents can successfully raise to inde- biologists vigorously dissented, "establish- pendence because these biological characteris- ment" ecologists regarded fluctuations as a tics are directly subject to natural selection. departure from the norm, and as such, a He argued that because reproductive poten- hazard to the population. Many theorists of tial is excessive (Darwin 1859), mortality both evolution and ecology argued that adap- must be density-dependent if a population is tations were required to damp fluctuations or to avoid fluctuations. The only adequately the fluctuations would become "random density-dependent regulating process he ac- walks" and the population would rapidly be- cepted was the population's response to its come extinct. As a consequence, relatively all food supply (Lack 1954). In fact, for many theoretical models included stability as a cen- years Lack rejected Kluyver and Tinbergen's tral assumption. (1953) hypothesis that territory could act as a

• The basic element of this theoretical com- control on population size in birds because, he plex has been the Lotka-Volterra formula for argued, territories were compressible and a logistic curve of population growth and sta- therefore allowed wide fluctuations. To his bilization. According to this formula it has credit, however. Lack eventually acknowl- been reasoned that by establishing the in- edged this mistake. herent rate of increase of a population (i.e., its The first defect in the concept of "carrying average natality relative to mortality, or r) capacity" is the idea that populations have and by measuring the carrying capacity of the "mechanisms" or "institutions" (Wynne- environment (which is the density of the popu- Edwards 1959) by which the population is lation at saturation, or K), one can predict the kept stable at the carrying capacity in a maximally productive population size, and stable habitat. POPULATION DYNAMICS IN NORTHERN MARINE BIRDS 127

The second defect in the concept of carrying Nettleship (1972), studying the effects of capacity is that it presupposes a stable envi- herring gulls on Atlantic puffins, showed that ronment. During the early decades of the 20th the effect of harassment and steahng food century most cUmatologists believed that a from the parents was to reduce the amount of departure from the norms of a regional cli- food brought to the young and thus reproduc- mate set processes in motion which would re- tive success. In those parts of the colony turn the climate to normal. During the last where gulls were numerous or where the decades, however, climatologists and puffins were at a disadvantage in escaping oceanographers have shown clearly that envi- from gulls (i.e., flat rather than steep slopes) ronments are continuously in flux. the reproductive success of puffins was significantly lower than in areas away from the gulls. An A ttack on Density-dependent The literal application of Andrewartha and Mortality Birch's general ideas also confhcts with observations on subtle adaptations some waterfowl Some theorists rejected the concept of have made to counter predation. carrying capacity as soon as it was formu- Barry (1967) described the density-avoiding lated. Andrewartha and Birch (1954) pre- adaptations of arctic-nesting geese to evade dicted fluctuations would be undamped by in- predation— specifically by foxes. Black brant herent population mechanisms but rather {Branta nigricans) nest on low coastal or delta would be controlled by external forces indif- islands seeking to escape by remoteness. ferent to the density. Their supporting data Snow geese (Chen caerulescens) are colonial were drawn from field studies of insects in on large, flat areas, seeking protection in num- arid cUmates. Some of their ideas are directly bers. White-fronted geese (Anser albifrons) relevant to seabirds; for example, their asser- are soUtary nesters on inland swamps, seek- tion that in many cases limits to carrying ing to be "over-dispersed" among scrub capacity of the habitat are not set in a way re- willow. sponsive to the density of the population. The Common eiders, black scoters (Melanitta number of occupiable ledges on a seabird cUff nigra), tufted ducks {Ay thya fuligula), and are fixed and when they are full no more birds other ducks select gull colonies as nesting can breed there regardless of the amount of habitat. Although there is Uttle doubt that food available. For another example, some the ducks choose gull colonies for nesting, biological processes act in a way that rein- there is some doubt as to the reasons. Finnish forces fluctuations. Predation can act in this biologists (summarized by Bergman 1957; way in the relatively closed system of a sea- Hilden 1965) have concluded generally that bird colony; i.e., the smaller the prey popula- gulls protect the duck nests from predation tion the larger the percentage taken by the by hooded crows {Corvus corone). predators. The importance of predation as a selecting factor is shown by the adaptations marine birds and waterfowl make to avoid it. The Assumption that Fluctuations The fact that large colonies of seafowl are Are Generally Present usually concentrated on isolated, predator- free islands is one obvious case (Lack 1966). Recently theorists have built models based Although their ideas are useful in under- on assumptions that fluctuations are a standing changes in many species, primarily general characteristic of population dy- insect populations, the generality of An- namics, such as Gilpin's (1975) model describ- drewartha and Birch's (1954) hypothesis is ing multiphased oscillations. He took account weakened because it conflicts with detailed of the fact that fluctuations (and models) be- studies of seabirds which show that in many come more complex as more species and non- cases local food resources do limit breeding linear effects are included. May and Leonard success. Ashmole (1963) showed this for tropi- (1975) emphasized that the effect of non- cal terns, and Hunt (1972) for some colonies of linearities is to make it impossible to speak herring gulls on the New England coast. even in principle of the equilibrium point of a 128 W. H. DRURY

community. They pointed out that even categories of seabirds, waterfowl, and shore-

though the model is deterministic (i.e., as- birds are to specific types of disasters, (2) how sumes that the system will come to equilib- quickly their numbers build up after they rium) the oscillations are so complex that they have been reduced, and (3) at what stages we may appear to be random, and it may be a can help them best (i.e., at the breeding very long time before the system returns to a grounds, at the winter gathering grounds, or position near its starting point. "On the other on migration). I believe that we already know hand a truly random ecological system could enough to design effective programs and to always be fitted by a suitably ingenious limit begin work. To this end some characteristics cycle. This suggests that ecological analysis of seabirds are identified which determine the which does not consider component processes population structures and ways in which their must be viewed with great suspicion" (Gilpin numbers respond to changes in the en- 1975). May and Leonard (1975) and Gilpin are vironment. both making a famiUar point—that neither the logic nor the interactions described in a formula will describe biological reality unless the assumptions are correct. They are also Habitat making a different point—that an ingenious mathematician can create a formula to de- Although the shaUow oceans, islands, and scribe almost any operation (whether its seashores are among the most permanent fea- workings are systematic or random), and the tures of the earth in general, the details of formula may seem to work. their numbers and distribution change Gilpin's moral is that one cannot learn very rapidly. Sandy shores are obviously being re- much that is helpful by studying fluctuations worked even in the short span of a single life- as such. One must study the factors control- time. Distribution of islands and the sediment ling populations. This is a very old idea. load, extent, and strengths of currents vary It would appear that defining carrying constantly in space and change with time. capacity and inherent rate of increase will not The food that seabirds use is patchy and be very instructive in managing seabird popu- subject to both short- and long-term fluctua- lations other than in speculating upon what tions in numbers and shifts in geography. might be ideal upper limits. It can also encour- Suitable breeding habitat is scattered, and in age the musty sophistry that when a popula- many places where oceanic conditions provide tion increases beyond this abstract carrying a good food supply there are no nesting sites. capacity it "needs" to be hunted to prevent Consequently, seabirds aggregate in colonies, overcropping resources and damage to itself often dense, and the colonies are clumped for through a population decline. But we will not geographical as well as biological reasons. have the time to carry out detailed studies of Lack (1966) discussed some general features life histories seeking for critical population- of how the breeding adaptations of seabirds habitat interactions over several fluctuations are adjusted to the distances the birds must for each species involved in a disaster before go to find food. The species which feed close to designing programs to help seabird popula- the nest characteristically estabUsh isolated tions to build up their numbers. territories or nest in small groups, and they accept many different kinds of nesting substrate. Their clutch sizes are large, individuals General Characteristics of move nesting sites readily, and their young Marine Birds and Waterfowl grow rapidly compared to the species which feed far at sea. Species which feed far at sea Because general theory does not seem to aggregate in large colonies. These species are work and because detailed studies take too often rigid in their requirements for suitable much time, I conclude that it is necessary to nesting sites, their clutches are usually identify certain general principles upon which limited to one egg per season, their young to base applied programs. These categories of grow slowly, and there seems to be strong at- knowledge include: (1) how vulnerable certain tachment to traditional colony sites. POPULATION DYNAMICS IN NORTHERN MARINE BIRDS 129

Breeding nated. An exception to this is the food sub- sidy provided by man, which seems to have Ashmole (1963) suggested that the clutch been important in creating a nonbreeding oceanic birds is small colo- size of some and population of herring gulls large enough to only part of the available habitat nies occupy form a "critical mass" for the formation of a because food resources within efficient com- new guUery. muting distance of the breeding site are limited. We can see this effect in the usual failure of common terns to raise a third chick, Age Structure even in the colonies that are surrounded by favorable habitat (Nisbet 1973). Herring gulls Because the main element of population whose colonies are close to sources of human size— the number of breeding adults— is refuse raise more young than do those whose limited by the number of breeding colonies colonies are at some distance (Drury 1963; and the food available to those colonies, one Kadlec and Drury 1968; Hunt 1972). assumes that the total numbers of seabirds is Ashmole (1963) suggested that during the much less than could be supported by the course of the breeding season the birds ex- larger areas of productive oceans. Hence one haust the available food supply. The vaUdity suspects that there is lessened competition of this suggestion is reflected in the long dis- for food outside the breeding season and that tances some species (petrels, boobies, murres, lack of competition for food is a major reason dovekies) go for food to feed their young. One for seabirds being long-lived, often to ex- would therefore expect that early nesting tremes little suspected until recently. Mortali- pairs would be more successful, and this ties of 10-12% per year are common, and some seems to be the case in herring gulls (Nisbet as low as 4% (wandering albatross, Diomedea and Drury 1972), kittiwakes (Coulson 1966), exulans; Tickell 1968) have been recorded. and red-billed gulls, Lanes novae-hollandiae In contrast, songbirds with large clutches, (Mills 1973). such as the titmice studied by Kluyver (1951), If food is in short supply and parents have produce a large number of young with whom to seek over a wide area for food so that they they and other adults must compete for food can bring back only a Uttle food at long time during the winter period of food shortage. Be- intervals, one would expect these birds to cause the titmice are permanent residents, have a small clutch and their young to grow they occupy all of the available habitat slowly, as is the case. One would also expect throughout the year. Hence titmice suffer in- seabird colonies situated near oceanic cur- tense intraspecific competition, which rents to be larger and more successful because shortens the survival of adults. Kluyver 's ex- food is continuously renewed. Conversely, one periments (1966) with nest boxes used by a would expect colonies next to still waters to closed population of great tits on Vlieland, be smaller and less successful. The Netherlands, showed that by artificially The small clutch size of seabirds means that reducing clutch size the survival of adults was when a population has been reduced, it will increased. grow slowly toward its former abundance. Similar competition for the few territories The growth rates of seabird populations on available on marshes and consequent short- the New England coast since their release ened life expectancy, can be expected in from human predation reflects this. Species waterfowl with large broods. The effect such as black guillemots with only two eggs should be less marked for geese with smaller per clutch and herring gulls with three eggs clutches that nest in less confined habitats. per clutch have increased more slowly than The long Ufe span of seabirds means that a have the populations of common eiders or population will have a large component of double-crested cormorants both with three to older age categories; this characteristic has six eggs per clutch (Drury 1973). several implications:

If the species that nest in colonies show a • It means that the population can survive high degree of site tenacity, they are not likely years of reproductive failure without the ob- to reestablish a colony after it has been elimi- servable immediate effects that would be 130 W. H. DRURY

manifest in titmice, grouse, or rabbits. Near feature must have adaptive significance. failure of reproduction during a breeding season among arctic seabirds at Bear Island was Wintering Grounds reported by Bertram et al. (1934). Many similar observations have been made since then: When colonial nesting seabirds leave their Pitelka et al. (1955) reported such a case breeding islands for their wintering grounds, among skuas and gulls at Point Barrow, their identification with that island is lost as Drury (1961) for greater snow geese (Chen far as population effects are concerned, be- cerulescens atlantica) at Bylot Island, Jones cause birds from many colonies mingle on the (1970) for black brant gathering at Isambek wintering grounds. Major mortality takes Lagoon on the Alaska Peninsula, and D. A. place on the wintering grounds and must Snarski (personal communication) for kitti- therefore act on the species population as a wakes at Cook Inlet. Reproductive failure can whole rather than differentially on individuals sometimes be chronic, as observed by Nisbet associated with especially dense colonies. (1972) for terns at Cape Cod, Massachusetts, Such a direct relation between colony density or by Drury (1963) and Hunt (1972) for and mortality would be necessary for density- herring gulls on the outer islands on the coast dependent mortaUty to regulate the number of Maine. of birds on a breeding colony. Conversely, one When reproductive failure becomes chronic cannot expect that aU colonies will decrease as observed on peregrine falcons {Falco pere- equally because mortality should be equally grinus) by Hickey (1969) and in ospreys distributed if all the population gathers on a (Pandion haliaetus) by Ames and Mersereau common wintering ground. Thus density-de- (1964), the population of adults may hold on pendence acts only in a very general way upon for a number of years without evident decline. the sum of animals considered as an abstract Damage to the structure of the whole popula- entity— the population. tion may be serious before any numerical re- In fact, on the wintering grounds, as shown sults are evident. by a graph of numbers of gulls reported on

• Although there may not be intensive com- Christmas Counts on Cape Cod, Massachu- petition for food in the habitat away from setts (Kadlec and Drury 1968), herring gulls breeding colonies, there is intense competition are very responsive to local conditions and for food and breeding sites at and around the move several tens of miles to gather at favor- colonies. Hence age and previous experience able feeding sites. An aerial survey of the in seabirds assume importance in establishing gulls on the East Coast of the United States territory and in breeding success. Associated (Kadlec and Drury 1968) showed that more with this is the tendency for immature birds than half of the gulls were gathered near to delay breeding until they are several years major food sources in large metropolitan dis- old and for the immatures to remain on feed- tricts. Most of the remainder were gathered ing grounds at some distance from the colo- near small fishing ports. Very few were nies. In some cases young birds may "hang scattered along the shoreline in what one as- around" breeding colonies and even feed some sumes is the traditional gull habitat. Later of the young. When young birds do first breed analyses of the relation between the distribu- they usually lay smaller clutches and raise tion of banding recoveries of birds in their fewer young than do older birds. The impor- first winter and the distribution of immatures tance of age and experience upon breeding as found on this winter census (Drury and success has been well documented for kitti- Nisbet 1972) suggested that proportionately wakes (Coulson 1966) and red-billed gulls more first-year gulls died in those areas where (Mills 1973). the birds were sparsely distributed than died The fundamental biological importance of in the crowded metropolitan areas. this delayed maturity seems to be emphasized These results suggest both that there is not by the persistence for several years of imma- a direct feedback between reproductive rate ture plumages, so clearly identifiable that and mortality, and that mortality may even even a human observer can recognize the age be inversely density-dependent on wintering of an individual. One assumes such an evident grounds. This last runs counter to traditional POPULATION DYNAMICS IN NORTHERN MARINE BIRDS 131

ecological ideas that density causes a change considered a major mechanism of population in mortaUty rate. The idea that individuals maintenance. If conditions deteriorate seri- gather where "hving is easy" and mortalities ously at one place so that the local popula- are low is consistent with the theory of natu- tions decline or disappear, dispersal from ral selection. One would not expect the food of other centers can be expected to repopulate the gulls to be evenly distributed, and one the area as soon as local conditions again be- would expect individuals to move away from come suitable. This subject has been treated areas where food is scarce and mortality is in more detail by Drury and Nisbet (1972) and high. Drury (19746). Occupation of new, or return to former, nesting sites has Differences in Breeding been recorded in detail for fulmars {Fulmaris glacialis) by Fisher Success Between Colonies (1952) and for herring gulls by Kadlec and Drury (1968). Dispersal is also known for Breeding success has been shown to vary waterfowl. Hansen and Nelson (1957) reported that of among individual pairs of gulls (Drost et al. some 8,000 brant banded in midsummer 1961). Certain groups of individuals nesting in on the Yukon delta 8 were recovered patches within a single colony have greater in northern Siberia and 28 in northern breeding success than do others (Coulson Alaska and arctic Canada. They suspected that pairing on the 1968; Drury and Nisbet, in preparation). Dif- wintering grounds was responsible for the ferences in breeding success also occur be- change in breeding areas, a change that would tween colonies (Frazer-DarUng 1938; Kadlec not be expected among other North American and Drury 1968; Drury and Nisbet 1972). species of geese. Similarly, wide dispersal Some colonies reproduce consistently better seems to occur in pintails {Anas acuta), than others— for example, the gull colonies mallards (Anas platyrhynchos), and wood close to fishing ports and metropolitan areas. ducks {Aix sponsa). Other colonies produce consistently fewer The general tendency for some individuals young, such as the colonies on the outer is- to disperse and the frequency of "extra lands in the Gulf of Maine (Drury 1963; Kad- limital" breeding attempts is especially well lec and Drury 1968; Hunt 1972). The popula- established in the Bering Sea region, in part tions of successful colonies grow while the at least because vagrants from Siberia or numbers of unsuccessful colonies decline, North America are readily identified as such. even during a period of general population in- In the Aleutian Islands, Emison et al. (1971) crease (Kadlec and Drury 1968). and Byrd et al. (1974) have enumerated the The difference between success and failure, nesting vagrants. For the Pribilof Islands, growth and decline, appears to lie in the food Kenyon and Phillips (1965), Sladen and available. Colonies increase where breeding (1966), Thompson and DeLong (1969) have recorded success is high and decrease where breeding the repeated appearance of birds of Siberian success is low. One important reason seems to distribution, and Fay and Cade (1959) and be that adult gulls may move to a more pro- Sealy et al. (1971) did the same for St. ductive colony even after they have nested Lawrence Island. with another colony (Drury and Nisbet 1972; One can conclude that a few individuals are Kadlec 1971). Such adaptations can be viewed constantly trying to settle in new geographi- as adjustments by which individuals meet the cal areas. As climatic and habitat conditions requirements of an environment in which the change, some populations are able to become availability of food and other necessities is estabhshed; for example, southern species patchy and shifting. such as mockingbirds (Mimus polyglottus), cardinals {Cardinalis cardinalis), and tufted Dispersal titmice (Pants bicolor) have settled in southeastern New England during the last 2 In general terms, the willingness of some in- decades. These southern species have received dividuals to disperse while the majority of much publicity. But at the same time, a less individuals remain loyal to a colony can be publicized dispersal of white-throated spar- 132 W. H. DRURY

rows {Zonotrichia albicollis), hermit thrushes tunity for dispersion among alternative breed- (Catharus guttatus), and dark-eyed juncos ing sites may be an important factor in the re- Uunco hyemalis) has resulted in new nesting gional persistence of a species on the margin records of more northerly species, also in of its range, as illustrated by the history of southeastern New England. laughing gulls (Larus atricilla) in New The ability (or lack of ability) of some or- England. ganisms to expand their ranges over time has Between 1875 and 1900 there were fewer been a subject of consideration for a number than 50 laughing gulls in Massachusetts of years by plant and animal geographers. An (Mackay 1893) and about 35 in Maine (Norton important botanical paper on this subject in 1924). In Massachusetts the laughing gulls all the Bering Sea region was presented by settled on one large island, Muskeget, where Hulten (1937), who analyzed the ranges of by 1940 there were about 20,000 pairs (Noble plants of the area of Kamchatka, eastern Si- and Wiirm 1943). Meanwhile, in Maine the beria, Alaska, and northwest Canada, show- population had been disturbed by sheep and ing that diverse floras occur in some re- men and had shifted about among seven is- stricted geographic areas. He called these lands. The Maine population grew to only areas "refugia," and postulated that many about 350 pairs by 1940 (Palmer 1949). species had survived Pleistocene glaciations The laughing gull population in both States in them because these refugia remained ice- has decreased since 1940. In Massachusetts, free. He, like Fernald (1925), was puzzled as to where all pairs occupied one island, the popu- why only certain species had been able to ex- lation had fallen to about 250 pairs by 1972, pand their ranges outward from these "areas but the Maine population, still divided into of persistence," while other apparently more five colonies, stabilized at 250 pairs (i.e., the "conservative" species were unable to do so. same as instead of only 1% of the Massachu- Similarly, there appear to be conservative en- setts population). demic bird species of the Bering Sea region: the extinct Commander Islands cormorant (Phalacrocorax perspicillatus), Steller's eider Use of General Principles in (Polysticta stelleri), spectacled eider (Lampro- Solving Conservation Problems netta fisheri), emperor goose (Philacte canagica), whiskered auklet (Aethia pygmaea), Game biologists have successfully main- least auklet {A. pusilla), parakeet auklet {Cyc- tained the populations of hunted animals by lorrhynchus psittacula), Aleutian tern (Sterna using a number of classical principles of game aleutica), red-legged kittiwake (Rissa brevi- management. They have controlled mortaUty rostris), bristle-thighed curlew (Numenius by regulating kill and have increased standing tahitiensis), long-billed dowitcher (Limno- stock by improving habitat on a local scale. dromus scolopaceus), surfbird {Aphriza vir- This seems to have worked in species which gata), black turnstone {Arenaria melano- are short-lived, have large clutch sizes or cephala), rock sandpiper {Calidris ptiloc- litters, and which occupy mosaics of highly nemis), and western sandpiper (C. mauri). productive "successional habitat." Seabirds, The ranges of horned puffins (Fratercula however, contrast with these species in a num- comiculata), Kittlitz's murrelet {Brachy- ber of important biological characteristics. ramphus brevirostris) and, perhaps, crested They have small clutches, postpone breeding auklet {Aethia cristatella) suggest that some until they are several years old, and are subspecies of "Beringian" seabirds have ex- ject to periodic or chronic reproductive fail- panded their ranges from Hulten's (1937) ures. Therefore, their populations are skewed "refugia." toward older animals and replacement of lost individuals is slow. Many seabirds, like some Dispersal and Regional Persis tence geese, have a high level of site tenacity and ofMarginal Populations thus may resist recolonization or fail in the attempt to recolonize a breeding site once eUmi-

The presence of several subelements of a nated from it. In those species studied it ap- species population and, therefore, the oppor- pears that the breeding birds at a small per- POPULATION DYNAMICS IN NORTHERN MARINE BIRDS 133 centage of colonies are responsible for a large number of population centers with having proportion of the annual crop of young. It is some movement of individuals between the probably dangerous, therefore, to risk either centers, but not too much. Because it is highly damage to or elimination of well-established improbable that a single catastrophe will af- colonies. fect more than a part of a species' range at Studies of kittiwakes by Coulson and White any time, the more numerous and widely (1958, 1961), sooty terns (Sterna fuscata) by scattered the partially independent segments Ashmole (1963) and Harrington (1974), At- of a population are, the better the species is in- lantic puffins by Nettleship (1972), and sured against extinction. This, of course, sug- Cassin's auklets {Ptychoramphus aleutica) by gests that the size of each colony may be less Manuwal (1974), and the practice of eider important for long-term survival than is the "farming" in Iceland indicate that the num- total number of colonies. ber of available territories or breeding sites One intuitively concludes that "conserva- may limit the size of a population and that tive" species, such as those endemic to the populations can be increased by increasing Bering Sea region (whose dispersal and colo- the number of sites available. This suggests nizing mechanisms seem to be poorly de- one way in which direct steps can be taken to veloped), are especially vulnerable to the ef- encourage the numbers of breeding seabirds. fects of local population crashes. These Other studies indicate that seabirds will move "local" species therefore deserve special into synthetic habitat such as created by the consideration. window ledges on buildings (Coulson and I would like to emphasize two points to be White 1958) or the islands created by dump- included in designing a "management" ing spoil from channel dredging operations program:

(Buckley and Buckley 1971, 1975; Soots and • It seems that the most promising manage- Parnell 1975). ment techniques will be built upon ensuring Most generalizations of population biology the health of colonies and the associated feed- have been derived from the study of insects, ing areas at which reproductive success is songbirds, or game species. It seems inadvis- high enough to "export" young. Thus it is able to assume that those principles will apply useful to identify those colonies which are ex- to seabirds without modification. For porting young and to give special care to their example, predation by gulls and ravens may preservation. As populations of prey species have a disastrous effect on a seabird colony at change locally, so will the success of the local low colony density but have progressively less nesting birds. A colony which is thriving at impact as the colony size and density in- one time may be barely maintaining itself at crease. Fox predation may have important ef- another (Ainley and Lewis 1974), or it may de- fects over most ranges of prey density be- crease, as in the case of "guano birds" during cause the presence of foxes has important El Nino years in the Peru Current. psychological effects. •Because centers of abundance of marine The habitats of seabirds include elements in birds shift (Fisher 1952; Drury 1963, 1974a), which birds are widely dispersed (feeding it will be prudent to plan for large areas and areas) and others in which birds are crowded over long periods of time. Harrison Lewis, a and narrowly localized (nesting sites). Thus ef- pioneer in seabird management in eastern fective programs of conservation should in- Canada, said (personal communication) that clude guarantees that a number of colony just as soon as he got approval of a new sea- sites be available in as widely dispersed a pat- bird sanctuary through the long corridors of tern as possible. Each productive feeding the distant government bureaucracies in Ot- ground should, if possible, have several tawa, the birds would move to a new island colony sites available. and he had to start the process all over again. We have argued elsewhere (Drury and Nis- The objective is to maintain a variety of bet 1972; Druiy 1974a) that one of the chief de- colony sites for populations to move among as fenses any population has against extinction local patterns of productivity in the shallow is the combination of being divided into a sea shift. 134 W. H. DRURY

Goals for Research on subadults visit and become estabUshed at breeding sites, why the visit Population Dynamics of Seabirds subadults the breeding sites and what effect their presence for of Purposes Conservation has on the territories and breeding success of their neighbors and biological relatives. 1. To learn the distribution and relative im- 5. To know enough about places where sea- portance of seabird colonies, the number of birds, waterfowl, and shorebirds gather on mi- pairs nesting and nonbreeding individuals at gration and during the winter to identify each colony, and the timing of breeding activi- those areas which need special protection ties for each geographical region. The most from effects of economic development. important step toward conserving marine a. It is important to determine the areas birds is to get public ownership and protec- where marine birds gather at sea when they tion for their breeding grounds. are away from their breeding grounds. What 2. To understand the Ufe cycle of key factors of habitat and food supply make cer- species. Three needs are clear: tain places preferable to others? What is the a. To identify key species whose biological relation between gathering grounds and characteristics can conveniently be studied underwater topography (banks and edges of and measured. Studies of these species may the continental shelf)? What are the seasonal be useful in monitoring the "health" of sea- and annual differences in preferred gathering bird breeding areas. grounds? What special hazards exist, such as

If it is established that the reproductive unusual extent of sea ice or exceptional success of certain species varies similarly in storms? response to changes in their marine habitat b. It is important to plot coastal areas (such as black-legged kittiwakes and horned where waterfowl and shorebirds gather on mi- puffins), one could use key species (black- gration, for molting, and during the winter. legged kittiwake) to assess the performance of Which open leads in the ice and patches of' those species in a colony whose breeding suc- open water at the mouths of rivers are of cess is difficult to measure (horned puffin). especial importance in spring? What shore- b. To develop efficient and practical ways lines and beaches act as "leading Unes" dur- of censusing and measuring productivity of ing migration? Which capes and points result crevice-, scree-, and hole-nesting species such in concentrated overflights of migrating as puffins and auklets. waterfowl, and hence are locations of un- c. To estabUsh annual differences in repro- usually high kills by hunters? What wetlands, ductive success and mortality rates by age bogs, coastal ponds, lakes, and lagoons are classes of the key species, and from these to used as gathering grounds and to what extent identify rates of population turnover so as to do waterfowl and shorebirds exchange be- be able to predict the effects of mass mor- tween gathering grounds? How much redun- taUties. dancy of wetlands is needed to make the wet- 3. To learn enough about the differences in lands system maximally productive for water- behavior and productivity among colonies to fowl and shorebirds? establish which colonies produce surplus Answers to these questions will identify young and which have low productivity. At which geographic areas deserve special pro- first, maximum efforts for conservation tection during development. The answers will should be concentrated at those sites which also identify the kinds of influences which produce surplus young. might lower the contribution of each critical 4. To learn about colonial behavior. Two area to the survival of seabirds, waterfowl, needs are apparent: and shorebirds. Areas identified as important a. To know enough about the Uves of indi- under these categories must be included in vidually marked birds of known age so as to policy decisions related to land-use planning be able to infer the behavior of population ele- and management. ments at all stages of their life cycle. 6. To learn more about the effects of vary- b. To know enough about the lives of sub- ing quantities of food on breeding behavior adult birds to understand what proportion of and performance: POPULATION DYNAMICS IN NORTHERN MARINE BIRDS 135

a. What are the effects of food abundance the most productive of sea waters, but are in early spring on date of laying, clutch size, among the least studied. Although some and egg size? species (black-legged kittiwakes, tufted b. What effects do storms have at dif- puffins, and fulmars) move into deep waters, ferent stages of the reproductive schedule? many species of marine birds of northern

c. What effects do quantitative and quaU- waters gather in large numbers on preferred tative (species composition of prey) changes in feeding grounds at or near the edges of conti- food supply have on the survival of chicks? nental shelves during their winter season d. What are the similarities and differ- (Fisher 1952; Tuck 1960). ences between what parents eat and what 8. To know more about the potential effects they feed their chicks? of proposed developments on seabirds and Although this is important basic biologi- waterfowl. cal knowledge, it contributes little to conser- a. To prepare models which will predict vation efforts because food differences result probabilities of contamination of breeding from changes in the ocean over which humans and feeding areas (summer, winter, and dur- can have little effect. ing migration) using existing knowledge of

7. To learn more about prey species and (1) areas of proposed mineral develop- their availability to marine birds: ment; a. To know more about the breeding (2) areas that will be influenced by sec- areas, reproductive rates, growth rates, and ondary development such as dredging new routes of dispersal of the major prey food harbors, laying subsurface pipelines; species. In most areas a few species of teleost (3) tidal and oceanic currents;

fish (e.g., Ammodytes) or Crustacea (e.g., (4) numbers of marine birds or water- copepods, euphausids, mycids, or amphipods) fowl using specific geographic areas and habi- make up most of the food of marine birds. Yet, tats (e.g., waters below nesting cliffs, feeding the barest minimum is known about the biol- grounds, wintering grounds, and gatherings ogy of such species. A good first estimate of during migration); the "condition" of the marine environment (5) the distribution and patchiness of can probably be made by measuring reproduc- habitats (i.e., the redundancy among and tive rates and growth rates of these key prey within habitats and the degree to which popu- species. Hence an efficient (though indirect) lations exchange between alternative way to measure those rates may be by moni- habitats); toring reproduction of birds. (6) the biological importance of species b. To know more about the density and in local ecosystems (Are they predators whose distribution of key prey items season by sea- effects increase diversity?); son, and to learn more about the relation of (7) the human importance of the species their abundance and distribution to their (Are they endemics? Do they have unusual availabihty to birds, as Bedard (1969) showed "charisma" for the pubUc?); for Calanus to least auklets, and Thysanoessa (8) the vulnerability of the species (Is its to crested auklets. distribution restricted? Is it subject to oil pol- There are some indications that the popu- lution? Are their preferred grounds near areas lation size of prey items can vary widely with- of high development potential?); out having a marked effect on the numbers of (9) the types of biological effects (e.g., their predators. Does commercial fishing for oil contamination of plumage, PCB contami- the large, predatory fish have a measurable ef- nation of food chains); and fect on the food available to marine fish? Do (10) whether the potential impacts are the large pollock and salmon fisheries (high reversible or irreversible and to what degree. seas) make zooplankton available to smaller b. To understand more of the effects of alcids? Do marine birds affect a fishery? hunting on the behavior of marine birds and oceanography waterfowl on their breeding grounds, and to T, c. To know more about the of continental shelf waters, more specifically assess the effects on breeding performance of I the waters between 6 and 60 m deep. The shal- changes in behavior which result from human I * low waters of continental shelves are some of activities (such as hunting or studying the 136 W. H. DRURY

birds). cause pets are predators and harass the wild-

c. To understand the effects of the pres- Ufe which may be feeding; ence of predators (whether introduced or na- d. flights of aircraft, especiaUy heU- tive) on breeding colonies in order to assess copters, near or over seabird cUffs because the importance of removing the predators or such flights may cause serious damage to preventing their access to breeding grounds. eggs and young; e. hunting, because the game becomes timid and flees from those who might enjoy The Relation of the Products watching wildUfe; f. snow machines, because their presence of Biological Research to is disagreeable to many and they provide easy Programs for Conservation of access by which disturbing activities may Marine Bird Resources reach into areas where wildUfe would otherwise be undisturbed. Although peaceful coexistence of wildlife 4. What Umitations or alterations are populations and economic development are needed in the existing legal institutions, such here assumed to be practical, some new social as the Marine Mammals Protection Act, the institutions are needed to control damaging instruments implementing native land claims, activities of people during economic develop- the process of Alaska State lands withdrawal, ment. Human activities and industrial prod- the conditions for leasing State and Federal ucts which damage wildUfe or their habitat lands for development of mineral resources, must be identified, as must the space and re- and traditional rights of private property? All sources which wildUfe require for survival and of these legal institutions are relevant to health. problems of wildUfe survival and restoration, 1. What seabird cUffs, islands, lagoons, wet- and within most of these institutions there lands, river mouths, and other habitat fea- exist confUcts between rights and benefits of tures are of first importance for breeding or special poUtical interests and the husbanding for maintaining the populations? Some small of renewable common property resources. areas of habitat are critical for the survival of Experience in Europe and in New England some species during periods of stress. Those suggests that if reasonable Umitations are set habitats need official recognition. Steps are on human activities and that if adequate needed to ensure that the habitats are money charge is made against those who maintained. profit by economic development to defray full 2. What physical expressions of economic social costs, wildUfe can continue to do weU. development are of Uttle, modest, or serious In most cases where damage has occurred it is impact on wildUfe and its habitat? These ac- because those who administer the public insti- tivities and constructions include harbors, tutions have failed to include consideration of storage sites, transshipment facilities, roads, the conmion property resources. pipelines, summer camps, and suburban or vacation developments. References 3. What kinds of human activities will disturb, damage, or change the behavior or ac- Ainley, D. G., and T. J. Lewis. 1974. The history of cessibility of wildUfe? Many activities of one Farallon Island marine bird populations. Condor group of people have secondary effects which 76(4):432-446. affect the enjoyment of resources for other Ames, P. L., and G. S. Mersereau. 1964. Some factors in the decline of the osprey in Connecticut. groups. These include Auk81(2):173-185. a. giU netting for salmon, which may kiU Andrewartha, H. G., and L. C. Birch. 1954. The dis- large numbers of murres and diving ducks; tribution and abundance of animals. Univ. Chi- b. release of predators on seabird nesting cago Press, Chicago, 111. 782 pp. Ashmole, N. P. 1963. The regulation of numbers of islands, which may kiU adults or inhibit their tropical oceanic birds. Ibis 103b:458-473. feeding their young; Bailey, E. P., and G. H. Davenport. 1972. Die-off of c. free running of pets (such as dogs and common murres on the Alaska Peninsula and cats) over wetlands or wildUfe habitat, be- Unimak Island. Condor 74(2):215-219. POPULATION DYNAMICS IN NORTHERN MARINE BIRDS 137

Barry, T. W. 1967. Geese of the Anderson River Cramp, S., W. R. P. Bourne, and D. Saunders. 1974. delta, Northwest Territories. Ph.D. Thesis. Univ. The seabirds of Britain and Ireland. Taplinger of Alberta, Edmonton, Alberta, Canada. 176 pp. Publ. Co., Inc., New York. 287 pp. Barry, T. W. 1968. Observations on natural mor- Darwin, C. 1859. On the origin of species by means tality and native use of eider ducks along the of natural selection. John Murray, London, Beaufort Sea Coast. Can. Field-Nat. 82(2):140- 490 pp. 144. Dement'ev, G. P., R. N. Meklenburtsev, A. M. Sudi- Bedard, J. 1969. Feeding of the least, crested, and lovskya, and E. P. Spangeberg. 1968. Birds of the parakeet auklets around St. Lawrence Island, Soviet Union. Vol. 2. (Translated from Russian.) Alaska. Can. J. Zool. 47:1025-1050. Israel Program for Scientific Translations, Jeru- Belopol'skii, L. 0. 1961. Ecology of sea bird colonies salem. 553 pp. of the Barents Sea. (Translated from Russian.) Drost, R., E. Focke, and G. Freytag. 1961. Ent- Israel Program for Scientific Translations, Jeru- wicklung und aufbau einer population der Silber- salem. 346 pp. mowe, Larus argentatus argentatus. J. Ornithol. Bent, A. C. 1919. Life histories of North American 102(4):404-429. diving birds. U.S. Natl. Mus. Bull. 107. 245 pp. Drury, W. H. 1961. Observations on some breeding Bent, A. C. 1921. Life histories of North American water birds on Bylot Island. Can. Field-Nat. gulls and terns. U.S. Natl. Mus. Bull. 113. 345 pp. 75(2):84-101. Bent, A. C. 1922. Life histories of North American Drury, W. H. 1963. Results of a study of herring petrels and pelicans and their alhes. U.S. Natl. gull populations and movements in southeastern Mus. Bull. 121.343 pp. New England. Pages 207-217 in CoUoque: Le Bergman, G. 1957. Concerning the problem of probleme des oiseaux sur les aerodromes (Nice, mixed colonies; the tufted duck and gulls. Die 1963). Inst. Nat. Rech. Agron., Paris. Vogelwarte 19(l):15-25. Drury, W. H. 1973. Population changes in New Bertram, G. C. L., D. Lack, and B. B. Roberts. 1934. England seabirds. Bird-Banding 44(4):267-313. Notes on East Greenland birds, with a discussion Drury, W. H. 1974a. Population changes in New of the periodic non-breeding among arctic birds. England seabirds. Bird-Banding 45(1):1-15. Ibis 13(4):816-831. Drury, W. H. 19746. Rare species. Biol. Conserv. Brown, R. G. B. 1967. Breeding success and popula- 6(3):162-169. tion growth in a colony of herring and lesser Drury, W. H., and I. C. T. Nisbet. 1972. The impor- black-backed gulls Larus argentatus and L. fus- tance of movements in the biology of herring cus. Ibis 109(41:502-515. gulls in New England. Pages 173-212 in Popula- Buckley, F. G., and P. A. Buckley. 1971. The breed- tion Ecology of Migratory Birds: a Symposium. ing ecology of royal terns {Sterna [thalasseus] U.S. Fish Wildl. Serv. Wildl. Res. Rep. 2. 278 pp. maxima maxima). Ibis 114(3):344-359. Dutcher, W. 1901. Results of special protection to Buckley, P. A., and F. G. Buckley. 1975. The signifi- gulls and terns obtained through the Thayer cance of dredge spoil islands to colonially nesting Fund. Auk 18(2):76-103. waterbirds in certain national parks. Proc. Conf. Dutcher, W. 1904. Report of the A.O.U. Committee on Management of Dredge Islands in North Caro- on the Protection of North American Birds for lina Estuaries, May 1974. N.C. Sea Grant Publ. the year 1903. Auk 21(suppl.):97-208. UNC-SG-75-01, Raleigh. Emison, W. B., F. S. L. Williamson, and C. M. Byrd, G. V., D. D. Gibson, and D. L. Johnson. 1974. White. 1971. Geographical affinities and migra- The birds of Adak, Alaska. Condor 76(3):288-300. tions of the avifauna on Amchitka Island, Coulson, J. C. 1966. The influence of the pair-bond Alaska. BioScience 21(12):627-631. and age on the breeding biology of the kittiwake Fay, F. H., and T. J. Cade. 1959. An ecological Island, gullRissa tridactyla. J. Anim. Ecol. 35:269-279. analysis of the avifauna of St. Lawrence Coulson, J. C. 1968. Differences in the quality of Alaska. Univ. CaUf. Publ. Zool. 63:73-150. birds nesting in the centre and on the edges of a Fernald, M. L. 1925. Persistence of plants in ungla- colony. Nature 217 (Feb. 3):478-479. ciated areas of boreal America. Mem. Am. Acad. Coulson, J. C. 1974. Kittiwakes Rissa tridactyla. Arts Sci. 15:239-342. Pages 134-141 in S. Cramp, W. R. P. Bourne, and Fisher, J. 1952. The fulmar. Collins, London. D. Saunders, The Seabirds of Britian and Ireland. 496 pp. Fisher, J., and R. M. Lockley. 1954. Seabirds: in- TapHnger Publ. Co., Inc., New York. 287 pp. An troduction to the natural history of the seabirds Coulson, J. C, G. A. Potts, I. R. Deans, and S. M. Eraser. 1968. Exceptional mortality of shags and of the North Atlantic. Houghton Mifflin Co., other seabirds caused by paralytic shellfish Boston. 320 pp. poison. Brit. Birds 61:381-404. Fisher, J., and H. G. Vevers. 1943. The breeding Coulson, J. C, and E. White. 1958. The effect of age distribution, history and population of the North on the breeding biology of the kittiwake Rissa tri- Atlantic gannet (Sula bassana). Part I. A history dactyla. Ibis 100(1):40-51. of the gannet's colonies, and the census in 1939. Coulson, J. C, and E. White. 1961. An analysis of J. Anim. Ecol. 12:173-213. the factors influencing the clutch-size of the kitti- Fisher, J., and H. G. Vevers. 1944. The breeding wake. Proc. Zool. Soc. Lond. 136:207-217. distribution, history and population of the North 138 W. H. DRURY

Atlantic gannet {Sula bassana). Part II. The Klein, D. R. 1959. Saint Matthew Island reindeer- changes in the world numbers of the gannet in a range study. U.S. Fish Wildl. Serv., Spec. Sci. century. J. Anim. Ecol. 13:49-62. Rep.-Wildl. 43. 48 pp. Flegg, J. J. M. 1972. The puffin on St. Kilda 1969- Kluyver, H. N. 1951. The population ecology of the 71. Bird Study 19:7-17. great tit, Parus major L. Ardea 39:1-135. Forbush, E. H. 1929. Birds of Massachusetts and Kluyver, H. N. 1966. Regulation of a bird popula- other New England States. Vol. I. Massachusetts tion. Ostrich 38 (Suppl. 6):389-396. Department of Agriculture, Boston. 481 pp. Kluyver, H. N., and L. Tinbergen. 1953. Territory Fordham, R. A. 1968. Dispersion and dispersal of and the regulation of density in titmice. Arch. the Dominican gull in Wellington, New Zealand. Neer. Zool. 10:265-289. Proc. New Zeal. Ecol. Soc. 15:40-50. Lack, D. 1948. Natural selection and family size in Fordham, R. A. 1970. Mortality and population the starling. Evolution 2:95-110. change of Dominican gulls in Wellington, New Lack, D. 1954. The natural regulation of animal Zealand, with a statistical apf>endix by R. M. Cor- numbers. Clarendon Press, Oxford. 343 pp. mack. J. Anim. Ecol. 39(l):13-27. Lack, D. 1964. A long-term study of the great tit Frazer-Darling, F. 1938. Bird flocks and the breed- (Parus major). J. Anim. Ecol. 33(Suppl.):159-173. ing cycle. Cambridge Univ. Press, Cambridge, Lack, D. 1966. Population studies of birds. Claren- England. 124 pp. don Press, Oxford. 341 pp. Gilpin, M. E. 1975. Limit cycles in competition com- Mackay, G. H. 1893. Observations on the breeding munities. Am. Nat. 109:51-60. habits of Larus atricilla in Massachusetts. Auk Gromme, O. J. 1927. Some highlights on the faunal 10(4):333-336. life of the Alaskan Peninsula. Milw. Public Mus. Manuwal, D. A. 1974. Effects of territoriality on Yearb. 7:30-45. breeding in a population of Cassin's auklet. Ecol- Hansen, H. A., and U. C. Nelson. 1957. Brant of the ogy 55(6):1399-1406. Bering Sea—migration and mortality. Trans. N. May, R. M., and W. J. Leonard. 1975. Nonlinear as- Am. Wildl. Nat. Resour. Conf. 22:237-256. pects of competition between species. SIAM J. Harrington, B. A. 1974. Colony visitation behavior Appl. Math. 29(21:243-253. and breeding ages of sooty terns {Sterna fuscata). Mills, J. A. 1973. The influence of age and pair bond Bu-d-Banding 45(2):1 15-144. on the breeding biology of the red-billed gull Harris, M. P. 1964. Aspects of the breeding biology Larus novaehollandiae scopulinus. J. Anim. Ecol. of the gulls Lotus argentatus, L. fuscus and 42:147-162. L. marinus. Ibis 106(4):432-456. Murphy, R. C. 1936. Oceanic birds of South Harris, M. P. 1976. The present status of the puffin America, Vols. I and II. Am. Mus. Nat. Hist., in Britain and Ireland. Brit. Birds 69(7):239-264. New York. 1245 pp. Harris, M. P., and W. J. Plumb. 1965. Experiments Murray, M. D., and R. Carrick. 1964. Seasonal on the ability of herring gulls Larus argentatus movements and habitats of the silver gull Larus and lesser black-backed gulls L. fuscus to raise novaehollandiae Stephens in southeastern Aus- larger than normal broods. Ibis 107(2):256-257. tralia. CSIRO Wildl. Res. 9:160-188. Hickey, J. J., editor. 1969. Peregrine falcon popula- dynamics of the tions—their biology and decline. Univ. Wisconsin Nelson, J. B. 1966. Population gannet at Bass Rock, with comparative informa- Press, Madison. 596 pp. tion for other Sulidae. J. Anim. Ecol. 35:443-470. Hilden, O. 1965. Habitat selection in birds: a re- 1972. Breeding success of the com- view. Ann. Zool. Fenn. 2(l):53-75. Nettleship, D. (Fratercula arctica L.) on different Holdgate, M. W., editor. 1971. The sea bird wreck mon puffin habitats at Great Island, Newfoundland. Ecol. in the Irish Sea, autumn 1969. Nat. Environ. Res. Monogr. 42:239-268. Council Publ. Ser. C, No. 4. 17 pp. Nicholson, A. J. 1933. The balance of animal popu- Hulten, E. 1937. Outline of the history of arctic and lations. Anim. Ecol. 2:132-178. boreal biota during the Quaternary period. Bok- J. Nisbet, I. C. T. 1972. Disaster year for terns. Man forlags Aktiebolaget Thule, Stockholm. 168 pp. and Nature, Dec. 1972:16-21. Hunt, G. L. 1972. Influence of food distribution and

human disturbance on the reproductive success Nisbet, I. C. T. 1973. Courtship-feeding, egg-size of herring gulls. Ecology 53(6):1051-1061. and breeding success in common terns. Nature Jones, R. D. 1970. Reproductive success and age 241:141-142. distribution of black brant. J. Wildl. Manage. Nisbet, I. C. T., and W. H. Drury. 1972. Post-fledg- 34(2):328-333. ing survival in herring gulls in relation to brood- Kadlec, J. A. 1971. Effects of introducing foxes and size and date of hatching. Bird-Banding raccoons on herring gull colonies. J. Wildl. Man- 43(3):161-172. age. 35(4):625-636. Noble. G. K., and M. Wurm. 1943. The social be- Kadlec, J. A., and W. H. Drury. 1968. Structure of havior of the laughing gull. Ann. N. Y. Acad. Sci. the New England herring gull population. Ecol- 45:179-200. ogy 49(41:644-676. Norton, A. H. 1921. Report of the field agent for Kenyon, K. W., and R. E. Phillips. 1965. Birds from Maine. Bird-Lore 23:355-356. the Pribilof Islands and vicinity. Auk 82(4):624- Norton, A. H. 1924. Notes on birds of the Knox 635. County region. Maine Nat. 4:35-39. POPULATION DYNAMICS IN NORTHERN MARINE BIRDS 139

Palmer, R. S. 1949. Marine birds. Harvard Bull. species new to North America. Auk 83:130-135. Mus. Comp. Zool. 102. 656 pp. Soots, R. F., Jr., and J. F. Parnell. 1975. Ecological Perrins, C. 1965. Population fluctuations and succession of breeding birds in relation to plant clutch-size in the great tit, Parus major L. J. succession on dredge islands in North Carolina Anim. Ecol. 34:601-647. estuaries. N.C. Sea Grant Publ. UNC-SG-75-27, Pitelka, F. A., P. Q. Tomich, and G. W. Treichel. Raleigh. 1955. Ecological relations of jaegers and owls as Thompson, M. C, and R. L. DeLong. 1969. Birds lemming predators near Barrow, Alaska. Ecol. new to North America and the Pribilof Islands, Monogr. 25:85-117. Alaska. Auk 86(4):747-749. Preble, E. A., and W. L. McAtee. 1923. A biological Tickell, W. L. N. 1968. The biology of the great alba- survey of the Pribilof Islands, Alaska. U.S. Fish. trosses, Diomedea exulans and Diomedea epo- Wildl. Serv., N. Am. Fauna 46:1-255. morpha. Antarct. Res. Ser. 12:1-55. Reed, A., and J.-G. Cousineau. 1967. Epidemics in- Tuck, L. M. 1960. The murres: their distribution, volving the common eider (Somateria mollissima) populations and biology. Can. Wildl. Serv., Rep. at He Blanche, Quebec. Nat. Can. (Que.) 94:327- Ser. No. 1.260 pp. 334. Uspenski, A. M. 1956. The bird bazaars of Novaya Sealy, S. G., F. H. Fay, J. Bedard, and M. D. F. Zemlya. U.S.S.R. Acad. Sci., Moscow. (Trans- Udvardy. 1971. New records and zoogeographical lated from Russian.) Canad. Wildl. Serv. Transl. notes on the birds of St. Lawrence Island, Bering Russian Game Rep. 4. 159 pp. Sea. Condor 73(3):322-336. Vermeer, K. 1963. The breeding ecology of the glau- Serventy, D. L. 1967. Aspects of the population cous-winged gull (Larus glaucescens) on Man- ecology of the short-tailed shearwater Puffinus darte Island, B.C. Occas. Pap. B. C. Prov. Mus. tenuirostris. Proc. Int. Ornithol. Congr. xiv:165- 13:1-104. 190. Wynne-Edwards, V. C. 1959. The control of popula- Sladen, W. J. L. 1966. Additions to the avifauna of tion-density through social behaviour: a hypothe- the Pribilof Islands, Alaska, including five sis. Ibis 101:436-441.

Time-Energy Use and Life History Strategies of Northern Seabirds

Erica H. Dunn Long Point Bird Observatory Point Rowan, Ontario, Canada

Abstract

Time and energy budgets can be compared among species of birds with very different ecology as a way of summarizing differences and as an approach to determining selective pressures on each species. This paper reviews time-energy use of northern seabirds. Energetic cost of maintenance (basal metabolism, thermoregulation, and procurement and processing of food) depends largely on

the following factors: (1) small birds have higher metabolic costs per unit size

than do larger ones; (2) body structure affects the cost of locomotion as well as of

food procurement; (3) cUmate affects metabolic costs; and (4) food availability and nutrition vary among food types, and throughout the year within a food type. Little is known of maintenance energetics in seabirds. Time and energy allocations to items beyond basic maintenance are also compared. Patterns and costs of molt and migration are known only in a general way, and the variety of possible patterns suggests that more research would be of value. Almost nothing is known of location and daily activities of seabirds outside the breeding season. The review of breeding season activities is more comprehensive, and stresses the variety of factors known to affect timing, and the total time devoted to and the energetic costs of various aspects of reproduction. Some of these factors are weather, year, geographic location, feeding conditions, age, sex, and distance of food source from the breeding colony. Species characteristics such as clutch size, egg and yolk size, developmental type, growth rate, food type, and behavior combine with environmental variables to make seabirds a very diverse group in time and energy budgeting. Time-energy studies and determination of productive energy (energy remaining after maintenance needs have been met) can be useful in pinpointing those groups of birds and the times of year when birds are most vulnerable to environmental stress. Life history considerations suggest that most seabirds are adapted to low population turnover and would not be able to recover quickly from sudden increases in mortality.

Effective management of a population re- phasize the wide variation of species ecology quires manipulation of the factors most criti- within this avian group. cal in causing population increase or decrease. Time and energy patterning is being used as Deciding what these factors are and which are the basis of ecological comparison for the fol- most suitable for effective manipulation is lowing reason. Any activity of an animal re- very difficult due to the complexity of Ufe quires time and energy use; therefore, the pat- cycles and possible factors affecting demog- terning of use makes a common thread to raphy. It takes a thorough knowledge of a which allocation to all activities in a bird's life species and of its relationships with the biotic cycle can be related. Time-energy patterns can and abiotic environment to make effective be compared among birds with diverse food management decisions. The following review types, habitats, life cycles, and life expec- of seabird time and energy use is meant to em- tancy, and therefore offer an opportunity for

141 142 E. H. DUNN

comparison not available through other kinds of analysis (King 1974). The amounts of time and energy allocated POWER (WATTS) by an organism to different aspects of survival and reproduction should be regarded as being molded by natural selection to optimize (not necessarily to maximize) lifetime reproductive output (Fisher 1958; Williams 1966; Schoener 1971). Thus, differences in time and energy use between species should reflect adaptation to different biotic and abiotic environments. By comparing time and energy use, one can gain insight into the selective pressures on each species and have a basis on which to compare complex ecology more meaningfully than if one listed other types of differences. This review of time-energy use in northern seabirds cannot be comprehensive, largely because many of the necessary data are lacking. It stresses major areas of difference, however, and points out aspects about which little is yet known.

Fig. 1. Energy cost of various metabolic functions in relation to body size in birds. "0° Existence" Cost of Living refers to total metabolic costs of caged birds held at 0°C. From Calder (1974). Every animal must expend a basic amount of energy on normal maintenance, excluding activities normally allocated to a relatively serines of similar size (Dawson and Hudson narrow time span, such as reproduction. This 1970). "existence energy" expenditure consists of The relationship between BMR and body basal metaboUsm, thermoregulation, and the size is paralleled by that between size and costs of gathering and processing food, and other metabolic costs, such as for thermo- could also be referred to as the animal's basic regulation at a given temperature and for ac- "cost of Uving." In discussing the compo- tivity (Fig. 1; Kendeigh 1970; Tucker 1970; nents of the cost of living, energy use is em- Schmidt-Nielsen 1972; Berger and Hart 1974; phasized and time largely ignored—partly be- Calder 1974). Basal metabolic rate can there- cause metabohsra occurs irrespective of time fore be used as an index of the overall cost of (it is not something the animal can turn off for Uving as far as metabohc functions are con- a period) and partly because time use in nor- cerned. Small birds must allocate a greater mal maintenance and foraging has been little proportion of their energy resources than studied. larger ones to merely staying alive, and have a higher cost of living. Metabolism The suggestion in Fig. 1 that it is easy to measure activity costs in a straightforward Basal metaboUc rate (BMR) depends manner is misleading, because the figure rep- greatly on body size (Lasiewski and Dawson resents measures taken under standard condi- 1967; Zar 1968), and the costs per unit size are tions. Factors known to affect the cost of higher for a small bird than for a large one flight, for example, include anatomical adap- (Fig. 1). The BMR is somewhat lower in sea- tations (such as wing loading and wing shape), birds and other nonpasserines than in pas- the type of fhght (ascending, descending, gUd- TIME-ENERGY USE AND LIFE HISTORY STRATEGIES 143

The energetic costs of thermoregulation under natural conditions are not easy to esti- 160 mate. Thermal energy is gained from and lost X to the environment, and the degree of ex- 6 change depends not only on air temperature -J but also on metabolic rate, insulation, body H 120 temperature, posture, humidity, convection, and radiation. Radiation, in turn, depends on cloud cover, shade, and reflective and absorp- 80 tive characteristics of the organism and of the environment (Porter and Gates 1969; Calder and King 1974). Most of these quantities are changing constantly, and insulation and LEVEL FLIGHT 40 metabolic rate may vary on a seasonal basis with acclimation (Dawson and Hudson 1970). At present, no direct measurement technique exists for determining natural thermo- 5 10 15 20 25 30 regulatory costs, although a few estimates FLIGHT SPEED - MILES PER HOUR have been made (King 1974), including several for seabird nestUngs (Dunn 1976a, 19766 for Fig. 2. Energy cost of flying at different speeds and double-crested cormorants, Phalacrocorax angles as compared with basal metabolic rate (BMR). Solid lines and solid circle refer to flight auritus, and for herring gulls, Larus argenta- cost and BMR for budgerigar (Melopsitticus tus). For most birds, the temperature environ- undulatus). Dashed line and open circle refer to ment actually faced over a year's time has flight cost and BMR of the laughing gull. From never been measured, and for no bird has a Tucker (1969). full description of the complete thermal environment been made. It is clear that cUmate ing), and the speed of flight (Fig. 2; Tucker and degree of exposure are important ele- 1969, 1974; Hainsworth and Wolf 1975). The ments in the basic cost of living, and that cost of a series of short flights may be higher thermoregulatory costs average higher in than that for a long one because of the extra small birds than in larger ones, but beyond energy required for takeoff and landing. A few that little information is available. Work on estimates have been made for the cost of thermoregulatory costs of free-living chicks of flight, mostly in birds moving almost con- two species of seabirds suggests that insula- stantly (Lasiewski 1963; Nisbet 1963; Tucker tive properties can lead to marked differences 1972, 1974; Utter and LeFebvre 1970; Berger in the metabolic costs of different species in and Hart 1974), but the methods may be in- an essentially identical environment (Dunn adequate for birds that fly short distances 1976a, 19766). frequently. Little work has been done on the cost of Food Procurement and Processing locomotion in seabirds: that of EUassen (1963) on great black-backed gulls (Larus marinus), Gathering and processing food is another Berger et al. (1970) on ring-billed gulls major component of the cost of living. Both (L. delawarensis), and Tucker (1972) on the the nutritional value of food and its avail- laughing gull (L. atricilla), and indirect cal- abihty (a rather vague term covering both culations of soaring flight characteristics in abundance and ease of capture) are extremely albatrosses, Diomedea spp. (Cone 1964), and diverse and variable, making estimations of the fulmar, Fulmarus glacialis ( Pennycuick foraging cost and benefit difficult (Ashmole 1960). Swimming has been shown to be more 1971; Fisher 1972; Sealy 1975a). costly than flying in ducks (Schmidt-Nielsen Availability of food varies throughout the 1972) and may be for seabirds as well. More year, particularly in marine invertebrates energy is also probably used in underwater that form the diet of many seabirds (e.g., swimming than in flying. Spaans 1971; Bedard 1969a). High arctic 144 E. H. DUNN

oceans have a very high peak of productivity in the summer, whereas the low arctic has a lower, but longer-lasting, peak (Ashmole 1971). Fish stocks increase in summer as well (Snow 1960; Pearson 1968; Sealy 1975a), and decline or disperse in autumn (Potts 1968). Catchability may also differ widely from year to year (e.g., E. K. Dunn 1973). Marine foods are likely to have a patchy distribution, which may make food stocks difficult to locate, even in times of abundance (Ashmole 1971; Sealy 1975a). Birds in locaU- ties with low food abundance frequently show alterations in time and pattern of foraging, sometimes even changing diets (Cramp 1972; Henderson 1972; Hunt 1972; Lemmetyinen 1972). The time and energy expended in finding and capturing food by different seabird 3.2 3.6 species must vary widely according to the 2.0 2.4 2.8 form of foraging used: plunge-diving, beach LOG AVERAGE WEIGHT BIRD scavenging, aerial robbing, underwater pur- Fig. 3. Time spent foraging in the breeding season suit, and so on. Even when different species as a function of body size. From Pearson (1968). have traveled the same distance to an identi- AT = arctic tern (Sterna paradisaea), CT = com- cal food stock, therefore, the costs of procure- mon tern (S. hirundo), ST = sandwich tern ment differ. (Thalasseus sandvicensis), K = black-legged Time and energy spent foraging depends kittiwake, P = common puffin, M = common murre, LBB = lesser black-backed gull, S = not only on abundance and ease of capture, shag. but also on nutritional return, and on the age and size of the bird. Fig. 3 shows that the smaller species in a seabird community may spend the most time foraging. Even though this illustration is taken from the breeding have often been accepted as the most impor- season when food demands of the young must tant determinants of foraging strategies be taken into account, it suggests a difference (Bookhout 1958; Emlen 1966; West 1967; based on cost of living according to size. Bryant 1973), they may frequently be less im- Age of the bird affects time and energy com- portant than nutritional value and digesti- mitment to foraging because younger birds bihty, also shown in Table 1 (PulUam 1974). are often less skilled at capturing food. This Since fish seem to be highly digestible, most has been noted particularly in long-Uved sea- of the energy contained in them is available to bird species (Orians 1969; Dunn 1972; LeCroy the consumer. There are, unfortunately, no 1972; Buckley and Buckley 1974; Barash data on the digestibility of marine inverte- et al. 1975). Older juveniles may be excluded brates, but those for insects suggest that di- from feeding areas by more experienced, terri- gestibiUty, at least of crustaceans with exo- torial adults (Moyle 1966), whereas imma- skeletons, is somewhat lower than that for tures are not (Drury and Smith 1968; In- fish. A bird would therefore have to eat a golfsson 1969). larger biomass of invertebrates than of fish to Nutritional and energetic return obtained satisfy the same energetic needs (although from food is a very important factor in forag- cost of procurement might not be as high as ing strategy that has not received the atten- for fish). tion it deserves. Table 1 lists the caloric value A bird must satisfy not only energetic of various foodstuffs and illustrates how Uttle needs, but also nutritional requirements. Fish

is known about foods eaten by seabirds. Al- are high in protein (Table 1), but what httle is though caloric content and abundance of food known of marine invertebrates suggests a low TIME-ENERGY USE AND LIFE HISTORY STRATEGIES 145

Table 1. Nutritional value of foods eaten by birds. After data in Hunt (1972) and E. H. Dunn (1973).

Percent fresh wt. Kcal/g composed oi fresh Digestive Kcal metabolizable Food type wt. HjO Fat Protein efficiency energy/g fresh wt.

Vegetable 1.2-5.2 59-86 0.4-3 3-5 30-32 0.3-2.3 Tropical fruits 1.2 75 8 1 Various seeds 4.0-7.3 3-13 1-40 10-29 76-80 3.0-5.2 Various insects 1.4-5.2 65-75 1-3 9-18 66-69 0.9-3.5 Whiting (fish) 1.1 81 79 0.9 Various freshwater fishes 1.2 75 5 18 81 Mix of fish eaten by double- crested cormorants on NE coast 1.1 74 1 16 82 0.9 Fresh herring and mackerel 1.9 67 13 19 Garbage ("average" mix) 1.5 67 8 19 Crab with eggs 1.0 68 5 1 Euphausid shrimp 0.8 80 2 1 Clam (edible part only) 0.8 80 1 13

proportion of protein in relation to total bulk. Time-energy Use Beyond Protein is vital to growth of nestlings (Fisher the Cost of Living 1972; Lemmetyinen 1972), and 4-8% protein in the diet seems to be required for minimal maintenance of adults (Martin 1968; Fisher 1972). Some seabirds (such as puffins, Frater- This section concerns variation in time and cula) that eat a varied diet raise their young energy allocated by seabirds to activities exclusively on fish (Bedard 19696; Nettleship above and beyond the cost of living—particu- 1972; Sealy 1973a). larly to migration, molt, and reproduction. Other aspects of nutrition, such as vitamins Allocation to such items as avoidance of pre- and minerals, are also important to avian dation and competition is not considered here, health (Brisbin 1965; Fisher 1972). To further because they are not readily analyzed as ac- complicate matters, nutritional values vary tivities to which time and energy are devoted with season, as do birds' requirements for in a specific part of the annual cycle. them (Myton and Ficken 1967; Moss 1972). The previous discussion dwelt on energy Adults must adjust their time and energy considerations and could have referred to al- allocation to foraging to optimize not only most any group of birds. The following treat- energetic, but also nutritional return. ment centers on time use of northern seabirds. Optimal time and energy allocation has Little is known of energetics beyond the cost been studied in theory (Orians 1971; Schoener of living, although estimates have been made 1971; Pulliam 1974; Katz 1974) and some di- for certain aspects of migration, molt, and re- rect observations have been carried out, production (Nisbet 1963; Hussell 1969; Hart largely on seedeaters (Bookhout 1958; Myton and Berger 1972; Payne 1972; Ricklefs 1974). and Ficken 1967; Royama 1970; Moss 1972; Essentially nothing is known, however, of the Willson 1971; Willson and Harmeson 1973). relationship of such costs to the amount of The direct studies, in particular, point out the energy available to the bird once basic mainte- basic importance of studying cost-benefit nance costs have been met (productive ratios by interrelating complex factors of food energy). Because such complete data are not availability, searching patterns, and type, available, the following account dwells largely size, and caloric and nutritional value of on variation in timing and total time devoted foods. to activities beyond basic maintenance. 146 E. H. DUNN

BREEDING MIGRATION MOLT SABINE'S GULL ARCTIC TERN

SHORT-DISTANCE MIGRANTS (GULLS, PETRELS, CORMORANTS)

SHORT- DISTANCE MIGRANTS (MANY ALCIDS)

GLAUCOUS GULL CASSIN S AUKLET

IVORY GULL

WINTER SPRING SUMMER FALL

Fig. 4. Typical patterns of generalized annual cycles in reproduction, migration, and wing molt in northern seabirds. Solid line shows reproductive season, dotted line the period of migration or dispersion, and dashed line the period of annual primary molt. Data from Dorst (1961), Stresemann and Stresemann (1966), and Ashmole (1971).

Migration whereas dispersal or nomadism takes place over a long period of the winter (Fig. 4). Among northwestern North American sea- Among species remaining in the northern birds, most coastal feeders, such as gulls, cor- hemisphere, younger birds frequently dis- morants, and many alcids and petrels, have perse greater distances than do breeding only a short southward migratory movement, adults (Coulson 1961; Kadlec and Drury 1968; and many others are more or less resident Southern 1967), and the degree of dispersal (Dorst 1961; Ashmole 1971). Terns, on the can vary among colonies of the same species other hand, migrate long distances in a short (Coulson and Brazendale 1968). time to places where small fish are available Energy costs of migration must vary ac- near shore in the winter. Other long-distance cording to distances covered and amount of migrants— Sabine's gull {Xema sabini), time allocated to migration. Aside from the jaegers (Stercorarius spp.), pelagic phalaropes references to cost of flight mentioned earher, {Phalaropus, Lobipes), and kittiwakes (Rissa however, migratory costs have scarcely been spp.)—tend to scatter widely over the south- studied. Dolnik (1971) has estimated that ern ocean, concentrating near areas of upwell- chaffinches (Fringilla coelebs) expend about ing (Dorst 1961; Ashmole 1971). Groups such as much energy migrating south as they as murres (Uria spp.), eiders (Somateria spp.), would on thermoregulation if they overwin- and grebes (Podiceps spp.) may move con- tered on their breeding grounds. Long-dis- siderable distances by swimming (Dorst 1961; tance migration is presumably selected be- Tuck 1960). True migration tends to take cause the birds are able to collect food more place directly before and after reproduction. efficiently, because the risks of death or in- TIME-ENERGY USE AND LIFE HISTORY STRATEGIES 147

Table 2. Wing molt in alcids. After Stresemann and Stresemann (1966).

Rapidity of wing molt and (indented) flight capability in molt Timing of start of molt Species

Slow During care of young Cassin's auklet, parakeet auklet Retained {Cyclorhynchus psittacula), whiskered auklet (Aethiapygmaea) Retained After young become independent Least auklet (A- pusilla), crested auklet (A. cristatella) Rapid After arrival in winter quarters Marbled murrelet, Kittlitz's murre- Poor let (Brachyramphas brevirostris) Almost synchronous After end of breeding Xantus' murrelet {Endomychura None hypoleuca) Synchronous As soon as young go to sea Guillemots {Cepphus spp.), murres, None razorbill (Alca tarda), dovekie lAlle alle) None In winter, after body molt Puffins

jury in migrating are less than in residency, moratus) and molt there may occur rapidly and so on. Interspecific and intraspecific com- (3.5 months in the arctic tern). Certain other petition may also be involved (Cox 1968). In long-distance migrants begin molt before other words, migratory patterns are selected leaving the breeding grounds (herring gull; to optimize survival and reproduction in alter- skua, Catharacta skua; Leach's petrel, nating environments (Cohen 1967; Drury and Oceanodroma leucorhoa; and fulmar), al- Nisbet 1972). though molt may be interrupted during mi- Although one may suspect that location of gration, as in Larus argentatus heuglini winter food supply is the main environmental (Stresemann and Stresemann 1966). Dura- factor affecting migratory patterns, there is tion, timing, and rapidity of molt are particu-

little direct evidence on the reasons for, or the larly varied among the alcids (Table 2). benefits accruing from, the different patterns A few unusual molt patterns are found in seen in seabirds. Study of cost-benefit ratios northern seabirds. The ivory gull {Pagophila of foraging in different stages of migration ebumea) has its major annual wing and body might help clarify the question. molt immediately before it breeds. In several other species such as the glaucous gull {Larus hyperboreus) and Cassin's auklet (Ptychoram- Molt phus aleuticus) the molt almost completely overlaps the reproductive cycle (Johnston Patterns of molt vary widely among sea- 1961; Payne 1965). Potts (1971) documented a birds. The commonest pattern is for a prenup- molt pattern in shags (Phalacrocorax aristo- tial body molt to occur in spring, and for an telis) which is more typical of tropical sea- extended wing molt to begin after the breed- birds. Several cycles of wing molt take place ing season and continue well into the winter simultaneously, each lasting more than a (Fig. 4). In short-distance migrants, molt may year, and molt ceases in winter. By the time overlap slightly with the end of breeding and breeding age is reached, each flight feather is can last up to 6 months, as in most gulls, replaced once a year. terns, alcids, nonmigratory jaegers, and cor- Within these broad categories of molt pat- morants (Stresemann and Stresemann 1966). tern there are sometimes variations according Long-distance migrants frequently delay to age, sex, and even subspecies (Stresemann molt until in the winter quarters (lesser black- and Stresemann 1966). Male common eiders backed gull, Larus fuscus; Sabine's gull; (Somateria mollissima) molt directly after jaegers; arctic tern. Sterna paradisaea; and mating, when their reproductive role is com- marbled murrelet, Brachyramphus mar- pleted, whereas females molt only after they 148 E. H. DUNN

have taken their young to sea. Nonbreeders other periods. For example, ivory gulls, which and failed breeders frequently begin molt breed in the high Arctic, molt when food re- while other adults are still raising young and sources have become abundant in the low Arc- not molting—e.g., many alcids, gulls, storm- tic but before the high Arctic breeding petrels, and fulmars (Stresemann and Strese- grounds have thawed sufficiently for reoc- mann 1966; Ingolfsson 1970; Harris 1971; cupation. Harris 1974; Sealy 19756). In ivory gulls, Speed of molt may also reflect availabihty which molt just before reproduction, and in of energy resources or of nutrients needed for Sabine's gulls, which complete molt just be- feather growth (Payne 1972), but must also be fore breeding, nonbreeders may extend wing influenced by the need for full flight capabili- feather growth into the breeding season ties to obtain food. The eider duck and many (Stresemann and Stresemann 1966). alcids that shed wing feathers almost simul- There is Uttle information on the energetic taneously do not need their wings for flight cost of molt, although there are indications of after the young have left the breeding colony. at least some expense. Belopol'skii (1961) Hydrodynamic considerations suggest that showed that nonmolting seabird species their fishing capabiUties may even be im- tended to gain weight after reproduction, proved (Storer 1960). This is not true for the whereas those that immediately started molt smaller species—e.g., Aethia molts only one tended to lose weight. Among other birds, feather at a time and retains full flight cap- however, it is common for individuals to gain abilities (Table 2). Chmate may also influence weight just before, and even during molt simultaneity of molt if heat loss in rapid molt (Payne 1972). The BMR is known to rise in is particularly severe. molting birds (Blackmore 1969; Lustick 1970; Payne 1972), from as little as 5% to as much as 34% above nonmolting levels. In one Reproduction study, about 35-40% of the increased BMR represented extra thermoregulatory costs in- Time use of seabirds is best known for the curred by lessening of insulation and increase reproductive period, when the birds are on in heat loss from well-vascularized new relatively accessible breeding grounds, the feathers; the rest of the increase represented weather is most suitable for observation, and the energetic cost of growing feathers (Gavri- academic researchers are freed from their lov 1974). The fact that molt rarely overlaps jobs. Even so, the details of timing are known with breeding suggests that the energetic for only a few of the species and localities on the North coast (e.g., cost, even if slight, may be incompatible with northwest American the already high costs of reproduction (Payne Drent and Guiguet 1961; Drent et al. 1964; 1972). Cassin's auklets, which do molt while Cody 1973; Sealy 1973a, 19756, 1975c). The breeding, may cease molt while feeding large following discussion emphasizes the multi- young (Payne 1965), and certain species inter- tude of environmental factors known to influ- rupt molt during migration (Stresemann and ence timing and total length of time devoted Stresemann 1966). Doubtless a rapid simul- to various aspects of the reproductive cycle. taneous molt is more costly than a long gradual one. Timing of the Season Rapid molt appears to occur at a time in the Each species of seabird returns to the annual cycle when food resources are abundant colony site when weather conditions have (spring or late summer), whereas extended ameliorated sufficiently to meet its particular molt generally occurs over winter (e.g., needs. For example, the early arrivals to is- Bedard 1969a). If one speculates that energy lands in the Barents Sea are murres, kitti- availability is the main determinant of molt wakes, and herring gulls, which need only patterns, one can also speculate on the cause small cracks in the sea ice to meet their feed- behind some of the more unusual patterns. ing requirements (Belopol'skii 1961). Eiders in Possibly birds in which molt and breeding North America also return early, when a few overlap either have extraordinary available ice leads have formed (Schamel 1974). Com- energy at that time or else face shortages in mon puffins (Fratercula arctica) and mew TIME-ENERGY USE AND LIFE HISTORY STRATEGIES 149

gulls {Larus canus) are somewhat later untU snowmelt (Belopol'skii 1961). Many arrivals, and terns and a few parasitic jaegers others, however, reach sexual maturity soon (Stercorarius parasiticus) are the latecomers after arrival on the breeding grounds, and a to Barents Sea colonies (Belopol'skii 1961). few (such as jaegers and kittiwakes) mature in The timing of the season (as illustrated in migration or on the wintering grounds (Belo- Fig. 5) varies widely among localities, and be- pol'skii 1961). Northern phalaropes (Lobipes cause of local weather patterns and ocean cur- lobatus) sometimes lay eggs as early as rents, this variation can be unrelated to lati- 1 week after arrival (Hilden and Vuolanto tude (Belopol'skii 1961). Examples of such 1972). This factor, in combination with timing variation are also known in North America: of arrival, affects the amount of time spent in

for instance. Leach's storm-petrels in Alaska prenesting activities (Fig. 6). Most species lay eggs 2 to 3 weeks later than do those in gain weight during this period (Belopol'skii California (Harris 1974); however, the details 1961), and the time required for each species of timing are largely unknown for many to reach full breeding condition must also de- species in this region. Progression of thaw, pend on feeding conditions and the state of which also varies from year to year, causes the bird on its arrival at the nesting site, variation in the timing of the breeding season These factors help explain why early arriving (Belopol'skii 1961; Evans and McNicholl species are not necessarily early nesters

1972). Fig. 6 shows the diversity in start of (Fig. 6). the breeding season for different species on the same island in the Barents Sea as well as PRE-LAYING INCUBATION NESTLING variation in time devoted to various compo- p BLACK GUILLEMOT 1 JV ,., "I nents of the reproductive cycle. SHAG COMMON MURRE THICK-BILLED MURRE BLACK-LEGGED KITTIWAKE 1 T X HERRING GULL COMMON PUFFIN A I'l T7~T MEW GULL B 45 PARASITIC JAEGER i:::::-::::::;:::::::-:- COMMON EIDER C 85 rz3 ARCTIC TERN ^^>--: :>::•:•:•:•:•::•::•:•:•:•:•-•' ••1 D 1 80 THICK-BILLED MURRE Fig. 6. Variation in timing of events in the reproductive cycle of Barents Sea seabirds nesting on the same island. Data from Belopol'skii (1961). 45 Shaded bars at left indicate the prelaying 55 JZ periods, open bars the incubation periods, and 70 E shaded bars at right the portion of the growth BLACK-LEGGED KITTIWAKE period in which the chick remains at the nest site. Total length of time indicated is about 6 months.

Fig. 5. Differential average arrival on breeding grounds and average duration of prenesting period of thick-billed murres (Una lomvia) and Aside from nest building, most prenesting black-legged kittiwakes on various colonies in the activity consists of courtship and territorial Barents Sea. From Belopol'skii (1961). Length of prenesting period in days (shaded bars) indicated behavior. These activities have been well de- on right. Letters represent locations as follows: A scribed for representative seabird species, but = Novaya Zemlya, Kara Straits; B = Novaya because assessments of time and energy de- Zemlya, Karmakuly Bay; = Franz Josef Land; C voted to them have been almost completely and D = East Murman. neglected, they are not discussed further here. For examples, see accounts in Gross (1935) for Leach's storm-petrel; Tinbergen (1935), Prenesting Activities Bengtson (1968), Hbhn (1971), and Howe Some species are apparently able to delay (1975) for phalaropes; Storer (1952) for com- maturity of sexual organs until environ- mon murre, Una aalge, and black guillemot, mental conditions are suitable for nesting— Cepphus grylle; Tschanz (1959) for common e.g., burrow and crevice nesters in the murre; Brown et al. (1967) for Sabine's gull; Barents Sea do not become sexually mature Tinbergen (1960) for herring gull; McKinney 150 E. H. DUNN

(1961) for eiders; Snow (1963) for shag; Thore- GLAUCOUS sen (1964) for Cassin's auklet; Vermeer (1963) GULL and James-Veitch and Booth (1974) for glaucous-winged gull (Larus glaucescens); and Andersson (1973) for jaegers.

Nest Building

Although many northern seabirds have essentially no nest, they may spend considerable time working or displaying at the site (Belopol'skii 1961). Black-legged kittiwakes {Rissa tridactyla) have substantial nests, but TEN-DAY PERIODS they are built in a comparatively short time Fig. 7. Timing of peak sexual activity (a combined (about a week) soon after the birds arrive measure of egg laying and testes size) in colonies (Fig. 6). Shags also have substantial nests, of arctic g^lls of different species composition. but they are not completed until about 1 or 2 From Smith (1966). weeks before the first egg is laid (Snow 1963). Herring gulls build smaller nests, 5 to 10 days before laying, although in the Far North they in mixed colonies, the peak of sexual activity and glaucous gulls may not start building the and egg laying in Thayer's gull is about mid- nest until the first egg is laid (Belopol'skii way between the peaks for the other two 1961). The eider always begins preparing the species (Fig. 7). In nearby colonies where nest when the first egg is laid (Belopol'skii herring gulls are absent, however, the peak of 1961; Schamel 1974), and terns and skuas, sexual activity in Thayer's gulls is delayed which build no nests, choose their sites at that about a week, and activity continues for a sig- time. Murres, which frequently lay their eggs nificantly longer period (Fig. 7). directly on snow, choose a site somewhat Annual variations in food supply also will earUer and spend considerable time protecting affect the start of the egg-laying season. Belo- it (Belopol'skii 1961). Burrows may be dug pol'skii (1961) cited an example from the within a period as short as 3 days for Leach's Barents Sea in 1940 when a series of storms storm-petrel (Gross 1935) to one as long as made it difficult for certain seabirds to find several weeks in Cassin's auklets (Manuwal food. Murres and kittiwakes, which were able 1974a). Overall, the prelaying period is longer to catch fish, started reproductive activities for burrow nesters than for those using on schedule. Gull breeding was delayed, how- crevices (Sealy 1973a). ever, and egg laying began in force only after The amount of time and energy spent by the fishing boats arrived and started discarding male and female in nest building differs offal. Onset of egg laying in great cormorants among species. In Leach's storm-petrel, the (Phalacrocorax carbo) is correlated to April air male digs the burrow (Gross 1935), whereas in temperatures (Erskine 1972), and this may eiders, the nest is built entirely by the female. also be related to variations in spring increase In most seabird species, the sexes share in of food availability. In certain birds the breed- nest construction, but roles may still be sepa- ing season has been shown to start particu- rated. For example, in shags the male collects larly early when food suppUes are unusually the nest material and the female builds the abundant (Hogstedt 1974; Kallender 1974), nest (Snow 1963). but this has not yet been demonstrated in seabirds. Lastly, age and sex of seabirds are known to Egg Laying affect the timing of egg laying (e.g., Coulson Timing of egg laying is influenced not only and White 1960; Lack 1966); older, more ex- by weather (Erskine 1972; Sealy 1975c), but perienced birds tend to lay earlier than do also by numerous biotic factors. Smith (1966) younger ones. In shags, males tend to breed showed that where glaucous gulls, herring progressively earlier as they increase in age, gulls, and Thayer's gulls [Larus thayeri) breed but females do not (Snow 1963). TIME-ENERGY USE AND LIFE HISTORY STRATEGIES 161

Contrary to the situation in passerines, sea- adult body weight than do semiprecocial and birds tend to lay their clutches with relatively precocial birds (Fig. 8). Clutch size, however, large time intervals between eggs. Eggs may is unrelated to energy content of the eggs. For be laid every 2nd or 3rd day in alcids, larids, example, shags (which are altricial) and eiders sternids, stercorariids, and phalacrocoracids (precocial) have among the largest clutches of (Lack 1968), but every day in phalaropes northern seabirds (four to six eggs). (Howe 1975). Inasmuch as clutch size in northern seabirds varies from one to five or six, the length of the laying period varies EGG WEIGHT - G widely among species. Energetic costs of egg laying depend on the actual caloric content of the egg and the speed with which the ova are developed (Ricklefs 1974). The energy in the egg is contained mainly in the yolk, and yolk size depends largely on the developmental pattern shown by the young after hatching (Table 3). Pre- cocial chicks are hatched at a relatively advanced stage, are covered with down, and have open eyes, can maintain reasonably homeothermic body temperature, and leave the nest site to feed themselves after a few hours or days. At hatching, semiprecocial chicks appear similar to precocial chicks, although they are slightly less well developed (Ricklefs 1974; Dunn 1975a). In contrast to precocial chicks, they remain at the nest site for some time, are fed by their parents, and tend to grow rather rapidly (Ricklefs 1968). Altricial nestlings hatch at a much less advanced stage of development. They are naked, bhnd, helpless, essentially poikilothermic, and Fig. 8. Egg weight as a function of body weight in depend completely on their parents for food various northern seabirds. Solid symbols represent precocial and semiprecocial species, and and shelter. They usually remain at the nest open symbols altricial and semialtricial species: until full grown. Semialtricial chicks show solid circles, alcids; solid triangles, gulls, terns, somewhat intermediate characteristics (Nice and jaegers; solid squares, eiders; open squares, 1962). cormorants and Moms bassanus; and open circles, petrels. Data from Belopol'skii (1961); Drent The amount of yolk (and therefore energy) (1965); Schonwetter (1967); Lack (1968); B6dard in an is positively correlated to the degree egg (1969c); Cody (1973); Sealy (19736); Harris (1974); of development at hatching (Table 3). The and Manuwal (1974a). same is true for egg size: altricial and semialtricial birds have smaller eggs relative to The energetic cost of egg laying depends not only on caloric content of the egg and clutch size, but also on speed of development. Table 3. Amount of yolk in eggs of different Ricklefs (1974) has shown that the energetic types of birds. After Ricklefs (1974). cost per day of egg laying can be calculated from the energy content of the yolk and white, Developmental Percent yolk clutch size, the amount of follicular growth type (by weight) per day, and the laying interval between eggs. Precocial 30-60 The energy content of a single egg (expressed Semiprecocial 25-30 as percentage of BMR) has been estimated as 15-25 Altricial follows: 45 (altricial passerines), 103 (semial- 9

152 E. H. DUNN

tricial raptors), 126 (precocial galliformes), Table 4. Predation on nests of common murres 180 (precocial ducks), 226 (precocial shore- according to degree of exposure. From birds), and 320 (semiprecocial gulls and terns). Belopol'skii(1961). Gulls and terns thus have very costly eggs, as Nests destroyed well as a moderately high clutch size (three). by predators However, the development time for a single Nest exposure (%) ovum in the herring gull is unusually long— to 10 days (King 1973). Ricklefs (1974), who Completely hidden 3.2 Partly exposed calculated the energetic cost per day (ex- 5.8 Largely exposed 13.6 pressed as percentage BMR), estimated the Completely exposed 18.2 cost of a clutch in gulls and terns (120% BMR per day) to be similar to that for various groups of precocial birds (about 125-180% BMR per day). Unfortunately, the data re- egg predation in common murres is correlated quired for calculation of the average energetic to degree of exposure of the nest— so even cost of a clutch are not available for other such an unUkely sounding factor as physical northern seabirds. characteristics of the nest site can affect the For no species have all the additional fac- average time and energy expended on egg lay- tors influencing the energetic cost of a clutch ing by a given species or population. Genuine been taken into account. For example, eggs in second clutches are occasionally laid by phala- a clutch may vary in size (and caloric content) ropes (Hilden and Vuolanto 1972) and according to sequence in the clutch (Preston Cassin's auklets (Manuwal 1974a). and Preston 1953; Snow 1960; Coulson 1963; In short, time and energy devoted to egg laying not only the species, also Coulson et al. 1969). Age has a definite effect depend on but on laying energetics, as older birds lay larger on a multitude of other biotic and abiotic fac- eggs (Coulson and White 1958; Snow 1960; tors, such as age, sex, degree of nest destruction, weather, other species present, and feed- Coulson 1963; Coulson et al. 1969) and lay larger clutches (Coulson and White 1960; ing conditions. Snow 1960). They also lay, on average, earher Incubation in the season (Coulson and White 1958; Snow 1960; Coulson et al. 1969), and eggs laid late The total time devoted to incubation does in the season (whether by young birds or older not depend directly on developmental type or ones in renesting attempts) tend to be smaller egg size but differs markedly among families and contain less energy. In addition, egg (Lack 1968). Since incubation period seems to quality can vary with food supply: Snow be closely Unked to fledging period, factors af- (1960) found eggs to have more yolk in years fecting growth rate (discussed later) ap- when food was abundant than in years when parently affect incubation period as well. food was scarce. Each species has a different incubation Egg-laying costs are, of course, borne en- rhythm. In birds in which the sexes share in tirely by the female, although males may con- incubation, the sexes exchange places at inter- tribute some time and energy toward egg lay- vals that differ widely among different birds: ing through courtship feeding (Ashmole 1971; several hours in lariforms and some alcids Henderson 1972; Nisbet 1973). Courtship (Drent 1965; Lack 1968; Preston 1968; Drent feeding takes place in most lariforms but not 1970); about 4 h in shags (Snow 1963); up to in eiders, phalaropes, or cormorants. 1 1 h in the ivory gull (Bateson and Plowright The time and energy expended on egg lay- 1959); up to 24 h in certain other alcids (Manu- ing can be profoundly influenced by the de- wal 1974a; Sealy 1975a); 33 h (on the average) gree of nest destruction, since females usually in common puffins (Myrberget 1962); 72 h in lay a replacement clutch if the loss of the first ancient murrelets, Synthlihoramphus an- does not occur too late in the season. Factors tiquus (Sealy 1975a); and 96 h in Leach's causing egg destruction are numerous, but storm-petrel (Gross 1935). Degree of atten- among the most important in the north is pre- tiveness once a bird is on the nest also varies. dation. As is shown in Table 4, the degree of Petrels may leave the egg for several days TIME-ENERGY USE AND LIFE HISTORY STRATEGIES 153

(Gross 1935), whereas herring gulls cover period depends on the stage of growth at their eggs 98% of the time (Drent 1970). which the young leave the nest and the rate at The sexes share in incubation in most sea- which they attain that stage. Growth rate in birds (Snow 1960; Drent 1965, 1970; Bedard turn depends largely on body size and de- 1969a), although females frequently take on velopmental type. the greater role (Belopol'skii 1961). Only male The stage of growth attained when birds

phalaropes incubate the eggs, and only female leave the nest varies considerably (Fig. 9). eiders. Eider hens do not feed during the en- Precocial eiders leave the nest within a day of tire incubation period (25 days) and leave the hatching, whereas altricial shags remain until nest only for short periods of about 10 min completely grown. The young of semiprecocial (Belopol'skii 1961; Schamel 1974). species, on the other hand, leave the nest at all Several methods exist for calculating the stages between these extremes. Larids nor- amount of heat input necessary for normal de- mally remain at the nest until 75-90% grown, velopment of a clutch of eggs (Ricklefs 1974). but certain alcids leave much sooner— well be- There is controversy, however, as to whether fore the young can fly. an adult can provide this warmth from excess body heat lost during the course of normal metabolism or whether the adult must raise SHAG its metabolic level to produce extra heat (Ken- :1 MEW GULL deigh 1973; King 1973; Ricklefs 1974). Several BLACK GUILLEMOT studies of incubating birds suggest that, in at ARCTIC TERN least some situations, adults need not raise GREAT BLACK-BACKED GULL metaboUc levels, but in others (large clutch, PARASITIC JAEGER BLACK-LEGGED severe weather), they probably do (Ricklefs KITTIWAKE HERRING GULL 1974). Drent (1972) estimated that herring COMMON PUFFIN gulls raise metaboUc levels to a significant de- DOVEKIE gree during incubation. COMMON MURRE In spite of the lack of quantitative data, one THICK-BILLED MURRE can surmise that the cost of incubation varies COMMON EIDER 50 among seabirds. Precocial and semiprecocial 100 PERCENT TOTAL GROWTH birds tend to have a larger clutch weight relative to body weight than to altricial birds Fig. 9. Percentage of total growth completed in the (Fig. 8; Lack 1968), and therefore require egg (shaded bar at left), at the nest site (open bar), greater heat input to the eggs. These costs and after nest-leaving (shaded bar at right) in various northern seabirds. From Belopol'skii may be reduced by heavily insulating the nest (1961). (e.g., eiders), or by nesting in burrows, which have much more moderate and even climates than do external nests (Richardson 1961; Manuwal 1974a). Other semiprecocial species, Growth rate depends both on body size and however, such as the murre, may sometimes developmental type (Fig. 10). The length of lay eggs directly on snow or ice (Belopol'skii stay at the nest for precocial young is unaf- 1961)—presumably at increased incubation fected by growth rate (which is typically very costs. Lastly, certain species incubate eggs slow), since they leave soon after hatching. with their feet (e.g., cormorants), rather than The nestling period of semiprecocial and altri- develop featherless brood patches. There are cial seabirds is, however, affected by the rate no measurements of comparative heat flow at which the young grow to the nest-leaving from feet versus brood patches. stage. This depends mainly on body size (Fig. 10) and to a certain degree on developmental type, as some semiprecocial species Raising Nestlings grow rather slowly. Certain seabirds with The length of the nestling period (hatching clutches of one egg grow particularly slowly until departure from the nest) varies greatly (petrels, some alcids, sulids). Several other al- among northern seabirds (Fig. 6). Nestling cids with single-egg clutches, however, grow 154 E. H. DUNN

1 -r 1 1—1 1 1 1 T ——1 1 1 1 TTT

A 100 • A. A A A • A A • A •a AA .A a A o • • °o A A • 9^ "" o o o A A "^ A " O • o A°V • o ^ • o o I o • • • • o •

— • • • A • • • 10

• t

^ ± • 1 i 111! i • • • • • 1 1 K) 100 1000 ASYMPTOTIC WEIGHT- GRAMS

Fig. 10. Growth rate as a function of body weight. Growth rate ^10-90 represents the number of days to grow from 10% to 90% of asymptotic weight (Ricklefs 1968). Data from Ricklefs (1968, 1973). E. H. Dunn (1973), and Sealy (19736). Solid circles and regression line, altricial birds; solid triangles, semiprecocial birds except for seabirds with one-egg clutches; open circles, precocial shorebirds; open triangles, precocial ducks, rails, and gallinaceous birds; solid squares, alcids with one-egg clutches; and open squares, northern petrels, gannet, and Manx shearwater (Puffinus puffinus).

at rates normal for semiprecocial chicks cocial seabirds, which are more fully de- (Fig, 10). Very slow growth may be related to veloped physically at hatching, attain control food stress (Lack 1968; Ricklefs 1968) or to re- of body temperature much sooner, in a matter duction of reproductive effort in the adults of several days, and precocial eiders can ther- (discussed later). Contrary to Cody (1973), moregulate within a few hoiu-s after hatching slow growth in alcids does not correlate to the (Table 5). distance adults must commute for food. (Cody Until the age of temperature control, nest- tried to directly compare growth in birds of lings must be brooded almost constantly, and different sizes.) Chicks in nocturnal species, occasional brooding takes place for some time however, tend to have slow growth rates afterward, especially in severe weather, in all (Sealy 19736). species studied (Tinbergen 1960; Belopol'skii Daily time budgets of adults raising nest- 1961; Weaver 1970; Dunn 1976a, 19766). lings also vary widely, depending on the Thermoregulatory capabilities in cold amount of brooding required, food require- weather are better in ducklings of species ments of the young, and foraging costs (which nesting at high latitudes than at lower ones differ in the breeding season from those at (Koskimies and Lahti 1964), and the same other times of the year). may be true of gull species (Dawson et al. Nestlings have imperfect control of body 1972). The cooling mechanisms of double- temperature at hatching (Fig. 11) and develop crested cormorants are better than in the this capacity only gradually. Altricial birds more northerly distributed pelagic cormorant, are hatched at a particularly undeveloped Phalacrocorax pelagicus (Lasiewski and stage; e.g., double-crested cormorants attain Snyder 1969). Thus, variation in cost of ther- reasonable control of body temperature in moregulation due to different environments moderate ambient temperatures only after may be reduced through adaptation. about 14 days (Fig. 11; Table 5). Semipre- Food requirements of the chick depend on TIME-ENERGY USE AND LIFE HISTORY STRATEGIES 155

CORMORANT

GULL

Fig. 12. Energy budgets of nestling double-crested 20 30 40 10 20 30 AMBIENT TEMPERATURE-»C cormorants and herring gulls. Data from E. H. Dunn (1973) and Brisbin (1965).

Fig. 11. Development of thermoregulatory capabilities in nestling double-crested cormorants. From Dunn (1976a). Ages at right refer also to corre- et al. 1969; LeCroy and Collins 1972; Lemme- sponding oxygen consumption data on the left. Thin diagonal lines show equality between body tyinen 1972; Cody 1973; E. H. Dunn and I. L. and air temperature. All data taken after 2 h of Brisbin, manuscript in preparation). Studies exposure. of double-crested cormorants by Dunn (19756) and pigeon guillemots {Cepphus columba) by Koelink (1972) have suggested that each adult growth rate, amount of fat deposition, cost of providing optimum amounts of food to a thermoregulation, degree of activity and normal-sized brood would have to approxi- other factors (E. H. Dunn 1973). Estimated mately double the amount of food gathered energy budgets for nestling double-crested each day over the amount gathered by non- cormorants and herring gulls in the same year breeders. This relation does not imply, how- and locality (Fig, 12) indicate that these fac- ever, that the time and energy allocation of tors vary according to developmental type, the adults would be the same for the two and comparison with budgets for nonseabird species. species suggests wide variation within de- Cost-benefit ratios of food gathering in the velopmental types according to the particular nestling period differ from those at other adaptations of each species to its own envi- times. Besides facing increased food demands, ronment (E. H. Dunn 1973). costs of delivery to the nest, and changes in Thus, the energy demands of nestlings are food availability, the parents' choice of foods not easy to predict. Brood size differences is constrained by the need to forage within multiply variation in food demand on adults reasonable commuting distance of the nest (except in precocial birds whose young feed and perhaps by concentrated competition themselves). Energy demands are labile, how- with conspecifics and other seabird species. In ever, particularly in requirements for activity addition, small nestlings are frequently un- and growth, and adults can frequently raise able to eat foods normally eaten by adults young successfully without providing opti- (Drent 1965; personal observation). In the mum amounts of food (Spaans 1971; Kadlec face of these constraints, adults often shift 156 E. H. DUNN

Table 5. Age of thermoregulatory control in various species of northern seabirds.

Age when moderate temperature control Species is attained (days) Source

Common eider 0.1-0.3« V. V. Rolnik, in Belopol'skii (1961) Herring gull 1.5-2 V. V. Rolnik, in Belopol'skii (1961) 2-3 E. H. Dunn (19766)

Leach's storm-petrel [2] Ricklefs(1974) Mew gull 2-3 V. V. Rolnik, in Belopol'skii (1961) Lesser black-backed gull 2-3 E. K. Barth (in Earner and Servent}' 1959) Greater black-backed gull 2-3 E. K. Barth (in Earner and Serventy 1959) Pigeon guillemot 2-4 Drent(1965) Common tern 3 LeCroy and Collins (1972) Roseate tern {Sterna dougallii) 3 LeCroy and Collins (1972) Common murre 3 V. V. Rolnik and Yu. M. Kaftonowski (in Sealy 19736) Razorbill (Alca torda) 3 V. V. Rolnik and Yu. M. Kaftonowski (in Sealy 19736) Black guillemot 3-4 V. V. Rolnik, in Belopol'skii (1961) Tufted puffin 3-5b Cody (1973) Northern phalarope 4-5C Hilden and Vuolanto (1972) Cassin'sauklet 5-6 Manuwal (1974a) Horned puffin (Fratercula corniculata) 2-6 Sealy (1973a) Common puffin 6-7 V. V. Rolnik and Yu. M. Kaftonowski (in Sealy 19736) Black-legged kittiwake 6-7 V. V. Rolnik, in Belopol'skii (1961) Double-crested cormorant 14 Dunn (1976a) Shag 12-15 V. V. Rolnik, in Belopol'skii (1961)

^Common eider, 2 to 7 h. ''No data given. <=Indirect evidence that young are brooded this long.

food preferences while raising nestlings (Belo- such as carrying more than one fish at a time, pol'skii 1961). For example, female mew gulls as in tufted puffins, Lunda cirrhata, and rhi- in the Barents Sea forage in the tidal zone, noceros auklets, Cerorhinca monocerata, vs. eating more small invertebrates than at other guillemots and murres (Richardson 1961; times of the year, while males continue to for- Cody 1973; Sealy 1973a, 19736); developing a age at sea and consume larger quantities of subungual storage pouch, as in Cassin's auk- fish (Fig. 13). lets (Speich and Manuwal 1974); or concentra- Commuting distances vary tremendously tion of food into stomach oil, as in petrels and among species (Fig. 14), but the number of feed- albatrosses (Ashmole 1971). Commuting ing trips to the nest per day does not corre- costs are largely eliminated when the young late with foraging distance (Cody 1973; Sealy leave the nest, but only in the alcids does nest 1973a, 19736). There is not, therefore, a leaving occur long before attainment of full simple relationship between time and energy growth. Early nest leaving may allow adults expenditures of the adults and foraging dis- and young to disperse to better feeding areas tances. Nocturnality, on the other hand, cor- than are exploitable from the colony site relates with reduced feeding rates (usually one (Sealy 19736) and probably involves a major visit to the nest each night). Seabirds feeding change in optimal food size and type as well far from the colony tend to show adaptations (Lind 1965). for bringing larger amounts of food per visit, Patterning of adult time budgets may differ .

TIME-ENERGY USE AND LIFE HISTORY STRATEGIES 157

CASSIN'S AUKLET 1 1

RHINOCEROS •

AUKLET 1

- TUFTED MALE'S 1 1 PUFFIN 1 1 1 FORAGING RANGE 1 MARBLED MURRELET 1 1 1

COMMON

1 MURRE 1

PISEON

1 1 GUILLEMOT ii 1 1

KILOMETERS FROM NEST SITE

Fig. 14. Percentage observations of foraging seabirds at different distances from the nest site. After Cody (1973). Each vertical bar represents

• •••••i"- 5% of total observations. Note nonlinear hori- ; WMm zontal scale. (<"•• •::!• • NEST--:/--. : •';-.•,'. '/; '. \ >i' '• • • A'

* "• • • *. \ >i;-V. : / • V ^^. 1^ g' • FEMALE'S "^ FORAGING RANGE ^:;i/^::^^: cids, and shags (Snow 1963; Vermeer 1963; Drury and Smith 1968; Ashmole and Tovar S. 1968; Potts 1968; Ashmole 1971; LeCroy ^^^ ^-^ 1972).

Fig. 13. Foraging ranges of a pair of mew gulls dur- Annual Time and ing the breeding season, on a Barents Sea colony. From Belopol'skii (1961). Energy Budgets

The discussion of time and energy allocation during reproduction was complex and de- between geographical regions. For example, tailed because so much more is known about rhinoceros auklets are nocturnal in the far the influences altering budgeting during this north (where the summer night is particularly period than during other times of the year. It short), crepuscular in the Olympic Peninsula, is likely that influences on molt and migration and mainly diurnal in the Farallon Islands will prove to be equally complicated, once (Manuwal 1974a). more is learned about them. Food demands of nestlings have a great in- If all data on time and energy allocation for fluence on the time and energy allocation of a single species were known, it would be pos- breeding over nonbreeding seabirds. Because sible to make up detailed budgets for birds of food is particularly abundant in the reproduc- different age, sex, and experience throughout tive season, however, one cannot ascertain the year. However, such detailed data have whether the vulnerabiUty of breeding birds to not been collected for any species. An annual time or energy crises is far different from that time budget for male and female yellow-billed at other times of the year. magpie, Pica nuttalli (Verbeek 1972), points out the great amount of difference between Postfledging Care the sexes (Fig. 15). A time and energy budget Little is known about the amount of care for the reproductive season only (Fig. 16) provided by adults to young after they are shows large differences between two closely fully grown. At least some species, such as related species, as well as between sexes; it gannets and procellariformes (Ashmole 1971), also indicates the wide difference between the are known to desert their young, whereas budgeting of energy as opposed to budgeting others are known to feed their young, at least of time. All other time-energy budgets to date occasionally, for some weeks or months after are for nonseabird species and for only a por- they can fly— e.g., terns and gulls, many al- tion of the annual cycle (Verbeek 1964; Verner —

158 E. H. DUNN

^ DRINK, BATHE that of productive energy— the amount of caloric intake left over after the birds' cost of Uving (metabolic functions and procurement and processing of food) have been accounted for. Costs are highest when temperatures are extremely hot or cold or when food is most difficult to obtain. Productive energy is highest in summer (Kendeigh 1972), and that is presumably why reproduction normally takes place then. It is unknown whether birds are more vulnerable to time and energy shortages in the harder nonbreeding season or in the breeding season after the extra demands of reproduction have been accounted for. Vulner- abiHty may also differ between sexes and among age groups. Time-energy studies, although useful in comparing ecology, determining vulner- abiUty, and cataloging location of birds, do have limitations. Careful studies are time-con- suming and are not the best approach to determining key factors influencing population increase or decrease. Even when different kinds of data are being sought, however, it is FEMALE worthwhile keeping the time-energy frame-

I I I I work in mind as a "big picture" into which T—————n J F MAM J J A S N other facts can be fitted and their significance MONTHS OF YEAR considered.

Fig. 15. Time budget of male (upper panel) and female (lower panel) yellow-billed magpies throughout the year. From Verbeek (1972). Nonlabeled Life History Strategies portions in each graph correspond to labeled sec- tions in the other. The study of life history strategies is largely theoretical, and in the following dis- 1965; Schartz and Zimmerman 1971; Stiles cussion I do not comment on current theoreti- 1971; Wolf and Hainsworth 1971; Smith 1973; cal arguments. On the other hand, life history Utter and LeFebvre 1973). strategies can be regarded as time and energy Time-energy budget analysis can be useful allocation on a grand scale, and it therefore in determining the leeway a bird has in surviv- seems appropriate to look briefly at their im- ing unusual stress at different times of the pUcations for seabird management. year. For example, a study by Feare et al. Annual reproduction evidently has a nega- (1974) showed that rooks {Corvus frugilegus) tive effect on resources remaining for other in the dry part of the summer spent 90% of functions, and may reduce the chances for an 15 h of daylight to collect 150 kcal of food organism to reproduce again in a later season energy. In winter, foraging in snow, the same (Cody 1966, 1971; Williams 1966; Gadgil and birds were able to collect 240 kcal of food in Bossert 1970; Gadgil and Solbrig 1972; only 30% of a 10-h day. This suggests that Hussell 1972; Trivers 1972; Calow 1973). If rooks would be far more vulnerable to unex- the chances of survival to another breeding pected periods of stress in late summer than season are small, the selective advantage lies in winter. Such information would clearly be with the bird putting the most effort into useful in making management decisions. early reproduction, in spite of its negative ef- A more precise measure of vulnerability, al- fects on survival, because future chances of though much more difficult to determine, is reproduction are small. If chances of survival TIME-ENERGY USE AND LIFE HISTORY STRATEGIES 159

F FEED Y0UN6 MSF FEED YOUNG F ON TERRITORY 15- 15 y ^ V'-\ / F ON TERRITORY rr^• ^ < 12- 12 1 M ON TERRITORY o ry , ON TERRITORY -1 %' hi 9 UJ :i H ! o. •I : I Ti V) 1 i (C 6 F DEFENDING II I o TERRITORY I ~\/ I "kX

M DEFEND TERRITORY^'V 1 X L. V U DEFENDING 3 TERRITORY»RiTORY^x;^^'-x I ; M a F MASS ^ \U 1 n i FEEDING FLIGHTS ^3*f^V-....# '1 1 I .^ sTU J ffl

Ma F FLYING TO FEEDING AREAS 250 250 • o n^

F M a F MASS FEEDING FLIGHTSI6HTS UJ SEARCHING ON a: FOOT FOR FOOD 150 150- > V o /'V CD< >-

F TERRITORIAL | o { DEFENCE-^ I M BF SEARCH FOR UJ 50 { 50 FOOT FLYING TO FOOD ON z M TERRITORIAL J I Itiy. UJ FEEDING AREAS DEFENCEEf'ENCE-^ i-j—AH' M TERRITORIAL DEFENCE^ ~ * JAN FEB MAR APR MAY JUN JAN FEB MAR APR MAY JUN RED-WINGED BLACKBIRDS TRICOLORED BLACKBIRDS

Fig. 16. Time and energy budgets of male and female red-winged iAgelaius phoeniceus) and tricolored (A. tri- color) blackbirds in the breeding season. From Orians (1961). Dotted lines show male (M) activity, dashed lines show female (F) activity, and solid lines show shared activities.

are good, however, it may be more advan- viduals may be favored that allocate re- tageous to reduce annual reproductive effort sources to attaining longer life (and more and allocate resources to other functions. chances to reproduce) or insuring greater Seabirds are generally long-lived, have chances of survival of their offspring (Murphy small clutches, and generally delay first 1968; Hairston et al. 1970). Density-inde- breeding until at least the 2nd year, and pendent mortality, on the other hand, is so un-

usually longer (Table 6). Phalaropes seem to predictable that there is no advantage in allo- differ from this pattern (Hilden and Vuolanto cating resources toward protection against it 1972; Howe 1975). Several ecological factors (Gadgil and Solbrig 1972). (not entirely independent) are believed to con- Two factors closely linked with density-de- tribute to the evolution of the long Ufe and pendence are high levels of competition, and low reproductive effort pattern favored by perennial difficulties in obtaining food. In seabirds. adapting to these difficulties, a bird may be

First, if population size is determined selected which develops more efficient forag- largely by density-dependent mortality, indi- ing techniques, wider dispersal, or better abili- 160 E. H. DUNN

Table 6. Life history data for certain northern seabirds.^

Annual adult Age at first survival breeding Clutch Species (%) (years) size

Fulmar 94 7 + 1 Gannet (Morus bassanus) 94 (4)-5 + 1 Manx shearwater 93-96 (4)-5 + 1 Shag 85(6) (2)-3 3-4 80(9) Herring gull 91-96 3.5(6) (2)-3 5 (9) Black-legged kittiwake 88 4-5(6) 3 3-4(9) Arctic tern 89-91 (2)-3 + 2 75 82b

Common murre 87 3 + ? 1 Black guillemot 88+c 3?<: 2«= Cassin'sauklet 83d 3d 1

^Data from Lack (1968) and Ashmole (1971) unless otherwise noted. bCullen(1957). cBirkhead(1974). dSpeich and Manuwal (1974).

ties to defend nesting territory— all of which 19746). Lack (1966) and Ashmole (1971) pre- may reduce resources available for reproduc- sented other arguments for density-de- tion. As mentioned earlier, marine foods tend pendence. Density-dependent mortality is dif- to be patchily distributed, and a long learning ficult to demonstrate, at best, and may be ob- period seems to be necessary before seabirds scured by interpopulation movements (Drury become proficient at foraging. In addition, and Nisbet 1972). there is evidence that food availability is low, If long life is a life history option, a low at least in the tropics, and perhaps in the win- annual reproductive effort could be favored in ter in other regions (Ashmole 1971). If nesting several ways. First, it may be necessary for in- places are in short supply, long hfe may be suring long life, if breeding has a serious nega- favored so that the bird can live long enough tive feedback on life expectancy (Calow 1973). for a place to become vacant. Several authors Second, if survival of offspring is more unpre- feel that competition is a serious factor in the dictable than that of adults, low annual effort life of seabirds, both for food (Lack 1966; may be selected so that reproductive effort Cody 1973) and for nesting space (Snow 1960; will not be wasted in years when young have Belopol'skii 1961; Lack 1966; Manuwal poor chances of survival. Unpredictable and 19746). Others, however, disagree, at least for variable first-year survival in seabirds has the breeding season (e.g., Pearson 1968). been documented (Potts 1968; Drury and Nis- There is some evidence of density-de- bet 1972). In addition, some seabirds show pendent population size control in seabirds, adaptations that allow high reproductive suc- although much of it is circumstantial. For cess in any given year but which do not drain

example, there are large nonbreeding popula- off resources if the season turns out to be poor tions in such diverse species as shags, herring (e.g., small last eggs in the clutch or asynchro- gulls, and Cassin's auklets, which move into a nous hatching, both of which lead to elimina- breeding area when estabhshed adults are re- tion of the smallest chicks when conditions

moved or colonize new breeding areas (J. C. are poor [Parsons 1970; E. H. Dunn 1973]). Coulson, personal communication; Kadlec and It should be emphasized that the factors in- Dniry 1968; Drury and Nisbet 1972; Manuwal volved in the evolution of life histories are TIME-ENERGY USE AND LIFE HISTORY STRATEGIES 161

complex and poorly understood, and simple cycles and the diverse responses among dif- formulas should not be expected to apply to ferent species to their environment. The main all situations (Wilbur et al. 1974). conclusion I stress is that each species (and In the framework of life-history strategies, age group and sex within that species) has a small clutch sizes and slow growth rates ex- different vulnerabiUty to stress, which may be hibited by some seabirds can be explained as most severe at different times of the year for adaptive reductions in annual reproductive ef- each group. To determine these periods of fort, rather than as responses to immediate stress, researchers may find a time-energy ap- food shortages. Arguments for this view are proach to be useful. presented on theoretical grounds (Dunn 1973) As for northwestern North American sea- and by the fact that many seabirds are able to birds in particular, ignorance is vast. Twelve raise larger than normal broods in certain years ago. Bourne (1963:846) noted the follow- situations (Vermeer 1963; Nelson 1964; ing needs in seabird research (among others): Harris 1970; Hussell 1972; Ward 1972; Cork- "The investigation of seabird biology has hill 1973). In addition, seabirds with particu- been reduced to a routine, but there is a great larly slow growth rates all grow at about the need for more study of some other aspects of same rate, regardless of body size (contrary to the Ufe or annual cycle, including events in the the situation in other birds). This suggests period immediately after fledging, and be- that low growth rates do not reflect varia- haviour and survival in the immature period tions in feeding abilities among species (Rick- and outside the breeding season. Much more lefs 1968). accurate information is needed about breed- Several conclusions relating to manage- ing distribution and seasons in many parts of ment of seabird populations can be drawn the world, about molting seasons and ranges from the above discussion. First, if population in most parts, and the distribution of birds of size is determined largely by density-de- different age groups during these periods in pendent factors, the birds are not adapted to practically all areas." precipitous unexpected decUnes in popu- and Since the time of Bourne's remarks, a num- lation levels. Because there is low annual re- ber of excellent studies have provided data on effort geared to a world in which productive the breeding biology of certain northwestern there is slow turnover in population, seabirds seabird species. Scientists remain largely are not able to rebound quickly from ignorant, however, about where birds of dif- Provision of excess food should not disasters. ferent age groups are located throughout the be expected to improve breeding performance, year. Such knowledge is necessary for effec- at least in experienced birds. tive protection and is basic to understanding Second, because seabirds are able to repro- population dynamics, even if it does not eluci- are duce in many different seasons and date causes. Studies of timing of annual within adapted to a low reproductive effort a cycles and movements should be carried out to be given season, one should expect them hand in hand with resource analysis—not just fail complete the re- easily disturbed and to to finding what birds eat, but discovering where productive cycle during any given breeding the food is at what times, how hard it is to indications of such failures attempt. A few catch, and what the nutritional return is. already observed (Erskine 1972; have been Much careful field work must be done before Manuwal 1974a; Nettleship 1975). effective management of most of our north- this discus- Again, the tentative nature of western seabirds can become a reality. sion should be emphasized, and conclusions drawn from it may not apply equally to all seabird species. References

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The role of time and energy in havior of grey and red-necked phalaropes. Ibis food preference. Am. Nat. 100:611-617. 113:335-348. Erskine, A. J. 1972. The great cormorants of east- Howe, M. A. 1975. Behavioral aspects of the pair ern Canada. Can. Wildl. Serv. Occas. Pap. 14:1- bond in Wilson's phalarope. Wilson Bull. 87:248- 23. 270. Evans, R. M., and M. K. McNichoU. 1972. Varia- Hunt, G. L., Jr. 1972. Influence of food distribution tions in reproductive activities of arctic terns at and human disturbance on the reproductive suc- Churchill, Manitoba. Arctic 25:131-141. cess of herring gulls. Ecology 53:1051-1061. Earner, D. S., and D. L. Serventy. 1959. Body tem- Hussell, D. J. T. 1969. Weight loss of birds during perature and the ontogeny of thermoregulation in nocturnal migration. Auk 86:75-83. the slender-billed shearwater. Condor 61:426-433. Hussell, D. J. T. 1972. Factors affecting clutch size Feare, C. J., G. M. Dunnet, and I. J. Patterson. in arctic passerines. Ecol. 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Johnston, D. W. 1961. Timing of annual molt in the Lind, H. 1965. Parental feeding in the oystercatcher glaucous gulls of northern Alaska. Condor Haematopus o. ostralegus (L.). Dan. Ornithol. 63:474-478. Foren.Tidsskr. 59:1-31. Kadlec, J. A., and W. H. Drury. 1968. Structure of Lustick, S. 1970. Energy requirements of molt in the New England herring gull population. Ecol- cowbirds. Auk 87:742-746. ogy 49:644-676. Manuwal, D. A. 1974a. The natural history of Kadlec, J. A., W. H. Drury, Jr., and D. K. Onion. Cassin's auklet (Ptychoramphus aleuticus). 1969. Growth and mortality of herring gull Condor 76:421-431. chicks. Bird-Banding 40:222-233. Manuwal, D. A. 19746. Effects of territoriality on Kallender, H. 1974. Advancement of laying of great breeding in a population of Cassin's auklet. Ecol- tits by the provision of food. Ibis 1 16:365-367. ogy 55:1399-1406. Katz, P. L. 1974. A long-term approach to foraging Martin, E. W. 1968. The effects of dietary protein optimization. Am. 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(Larus argentatus). Nature (Lond.) 228:1221- Sealy, S. G. 1975a. Feeding ecology of the ancient 1222. and marbled murrelets near Langara Island, Payne, R. B. 1965. The molt of breeding Cassin auk- British Columbia. Can. J. Zool. 53:418-433. lets. Condor 67:220-228. Sealy, S. G. 19756. Aspects of the breeding biology Payne, R. B. 1972. Mechanisms and control of molt. of the marbled murrelet in British Columbia. Pages 103-155 in D. S. Farner and J. R. King, Bird-Banding 46:141-154. eds. Avian biology. Vol. II. Academic Press, New Sealy, S. G. 1975c. Influence of snow on egg-laying York. in auklets. Auk 92:528-538. Pearson, T. H. 1968. The feeding biology of sea-bird Smith, C. R. 1973. Time budget of the loggerhead species breeding on the Fame Islands, North- shrike in southwest Florida. Abstracts of papers umberland. J. Anim. Ecol. 37:521-552. presented to the Wilson Society meeting, Cornell Pennycuick, C. J. 1960. Gliding flight of the fulmar University. petrel. J. Exp. 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Tucker, V. A. 1974. Energetics of natural flight. {Larus glaucescens) on Mandarte and Cleland Is- Pages 298-328 in R. A. Paynter, Jr., ed. Avian lands. Ph.D. Thesis. Univ. of British Columbia, energetics. Publ. Nuttall Ornithol. Club 15. Vancouver. Utter, J. M., and E. A. LeFebvre. 1970. Energy ex- Weaver, D. K. 1970. Parental behavior of the penditure for free flight by the purple martin herring gull (Larus argentatus smithsonianus) (Progne subis). Comp. Biochem. Physiol. 35:713- and its effect on reproductive success. Ph.D. The- 719. sis. Univ. of Michigan, Ann Arbor. Utter, J. M., and E. A. LeFebvre. 1973. Daily West, G. C. 1967. Nutrition of tree sparrows during energy expenditure of purple martins (Progne winter in central Illinois. Ecology 48:58-67. subis) during the breeding season: Estimates Wilbur, H. M., D. W. Tinkle, and J. P. Collins. 1974. using DjO" and time budget methods. Ecolog>' Environmental certainty, trophic level, and re- 54:597-604. source availability in life history evolution. Am. Verbeek, N. A. M. 1964. A time and energy budget Nat. 108:805-817. of the Brewer blackbird. Condor 66:70-74. Williams, G. C. 1966. Adaptation and natural selec- Verbeek, N. A. 1972. Daily and annual time budget tion. Princeton Univ. Press, Princeton, N. J. of the yellow-billed magpie. Auk 89:567-582. Willson, M. F. 1971. Seed selection in some North Vermeer, K. 1963. The breeding ecology of the glau- American finches. Condor 73:415-429. cous-winged gull (Larus glaucescens) on Man- Willson, M. F., and J. C. Harmeson. 1973. Seed pref- darte Island, B. C. B. C. Prov. Mus. Occas. Pap. erences and digestive efficiency of cardinals and 13:1-104. song sparrows. Condor 75:225-233. Verner, J. 1965. Time budget of the male long-billed Wolf, L., and F. R. Hainsworth. 1971. Time and marsh wren during the breeding season. Condor energy budgets of territorial hummingbirds. 67:125-139. Ecology 52:980-988. Ward, J. G. 1972. Studies on the feeding ecology Zar, J. H. 1968. Standard metabolism comparisons and breeding success of the glaucous-winged gull between orders of birds. Condor 70:278.

(s Zoogeography and Taxonomic Relationships of Seabirds in Northern North America

M. D. F. Udvardy California State University Sacramento, California 95819

Abstract

The zoogeography and taxonomic relationships among 42 Hving and 1 extinct species of marine birds from the northern and northwestern coasts of North America are described. Seventeen species are circumpolar in distribution; 17 are endemic to Beringia, and 8 have origins in the North Pacific.

This discussion concerns the northern and greatest attention. The pelagic cormorant western coasts of the continent, from about {P. pelagicus), Brandt's cormorant {P. penicil- the Mackenzie Delta westward and south- latus), and the double-crested cormorant ward to the mouth of the Columbia River. Be- {P. auritus) are widespread and successful, ex- sides bona fide seabirds, I include marine tending south of the area here considered; birds that predominantly breed and feed on or double-crested cormorants also breed inland around the marine littoral, but exclude two and across toward the North Atlantic coast. groups: shorebirds, jaegers, and phalaropes, As fish-eaters they are often persecuted where which breed inland and move out from the coastal fishermen possess firearms, and thus Arctic after an undetermined postbreeding are sensitive to increasing human influence on period; and Anseriformes which become the coasts. "marine birds" in their southern winter quar- Two species of arctic geese need special at- ters. What remains is 42 living species tention. The emperor goose {Philacte cana-

(Table 1). gica) is a Beringean endemic and lives in a The Procellariiformes, or tube-nosed sea- very restricted area of both sides of this sea; birds, have a predominantly southern hemi- its status (endangered?) is unknown to me. spheric, Gondwanan distribution. The North Since the black brant {Branta bemicla) is a Pacific basin is an important feeding ground long-range migrant, it is hunted as a game of several shearwaters (Puffinus spp.) that bird at its winter grounds, and subject to breed in the South Pacific and subantarctic. management measures. Whereas the emperor Only three species breed in the area under con- goose is a unique offshoot of the genus Anser, sideration: the fulmar {Fulmarus glacialis) the Pacific brant is considered a subspecies; and two storm-petrels (Oceanodroma spp.), all its general distribution is circumpolar. of which are still relatively widespread. Five arctic ducks, and one other, constitute Of the Pelecaniformes, the very successful, the sea ducks of the area. The common eider worldwide cormorants (Phalacrocorax spp.)— (Somateria mollissima), king eider (S. spec- inland water as well as coastal and "am- tabilis), and the oldsquaw (Clangula hyemalis) phibious" species are on every continent—are are widespread, and circumpolar or nearly so; ancient Pacific dwellers, with a high grade of hunting and down-robbing in other parts of endemism here: Of the two subarctic species, the Arctic may provide clues as to their rela- one {P. perspicillatus) became extinct long tive tolerance of primitive or advanced civili- ago, and the other, the red-faced cormorant zation. The spectacled eider (S. fischeri) and {P. urile), is very restricted, and deserves our Steller's eider (Polysticta stelleri) are re-

167 168 M. D. F. UDVARDY

Table 1. Seahirds in northwestern North America, (x = breeding, w = wintering or transient, () = either scarce or restricted distribution, * = stragglers only, nesting status unclear)

Distribution

Temperate Widespread North South northeast Circum- in North coast of Aleutian coast of Pacific Species polar Pacific Alaska Beringia^ Islands Alaska^ coastc

Fulmarus glacialis X w X X X w Oceanodroma furcata X X X X 0. leucorhoa X X X X X Phalacrocorax auritus X X X P. penicillatus (x) X P. pelagicus X X X X X P. urile X X X Branta bernicla X X X (w) (w) w Anser canagicus X w w Clangula hyemalis X w X X w w w Histrionicus histrionicus X w w w w w Polysticta stelleri X X (w) Somateria mollissima X X X X X S. spectabilis X X X w (w) S. fischeri X X Larus hyperboreus X w X X w w w L. glaucescens X X X X L. occidentalis (X) L. argentatus X w X (x)w L. thayeri w X w w w w L. canus X w X X (x)w Rissa tridactyla X w X X X X w R. brevirostris X X (X) Xema sabini X X X w Sterna paradisaea X w X X X w S. aleutica X X Uria aalge X X (x) X X X X U. lomuia X X X X X X Alle alle X * Cepphus grylle X X w C. columba X X X X X Brachyramphus marmoratus X (x) X X B. brevirostris X X X Synthliboramphus antiquus X X X X X Ptychoramphus aleuticus X X X Cyclorrhynchus psittacula X X Aethia cristatella X X A. pusilla X X A. pygmaea X Cerorhinca monocerata X X X Fratercula corniculata X X X X X Lunda cirrhata X X X X X Total number of nesting species 17 11 15 27 25 24 17 Total number of wintering species 9 4 7 9 9 Grand total 17 20 15 31 32 33 26

"Beringia comprises the islands and coasts of the Bering Sea. ^South coast of Alaska extends from the tip of the Alaska Peninsula to Glacier Bay. f^Temperate northeast Pacific coast extends from Glacier Bay south to the mouth of the Columbia River. ZOOGEOGRAPHY AND TAXONOMIC RELATIONSHIPS 169

stricted to the Bering Sea coasts and neigh- tention should be paid to the whiskered auklet boring High Arctic coasts, respectively; their {Aethia pygmaea) of the Aleutian chain; the status is precarious. Kittlitz's murrelet (Brachyramphus breviros- The harlequin duck {Histrionicus histrioni- tris) of the eastern Beringean and southern cus) stands alone without close relatives. It Alaska coast; and to the widespread, but very often breeds far from the sea, but spends the sporadic rhinoceros auklet, or puffin (Cero- shortest time—only a few weeks—away from rhinca monocerata). the rocky coast. There is a year-round popula- To sum up, I have tabulated these 42 tion of yearlings in the sea. The drakes of the species, and indicated whether modern life- nearest breeding pairs at lower latitudes are history and population studies are extant: back to the sea, abandoning their mates at the No. No. breeding stream when the alpine stream- species studied dwellers are still at sea awaiting the thawing Procellariiformes 3 2 of their breeding grounds. Harlequin ducks Phalacrocorax 4 2 live in large parts of Siberia, from arctic Anseres 2 1 Alaska to central California and Colorado, Anates 6 — and also in the eastern Arctic. They do not Lari 9 2 seem to me to be in immediate danger Sterni 2 — globally, though perhaps they are locally. Alcidae 16 7 Gulls are a highly successful group of sea- Total 14 birds, and of the eight species on our coasts 42 the four more southern ones—the western gull

(Larus occidentalis), glaucous-winged gull Thus, 28 species await studies preliminary to, (L. glaucescens), common gull (L. canus), and and highly necessary for, conservation herring gull (L. argentatus)— are expanding measures. wherever civilization creates new scavenging Seventeen species of marine birds are opportunities. Nothing is said about the popu- spread either circumpolarly around the north- lations of the kittiwake {Rissa tridactyla), ern perimeter or along the north-south coasts black-legged kittiwake {R. brevirostris) and of the Laurasian continents. Four of these are Sabine's gull (Xema sabini), or of the other of the High Arctic (Branta bemicla, Somateria two high arctic species {Pagophila eburnea, spectabilis, Xema sabini, Alle alle); another Rhodostethia rosea) which do not nest regu- seven penetrate the Bering Sea as well {Ful- larly in the area considered here. marus glacialis, Somateria mollissima, Clan- The arctic tern (Sterna paradisaea) is cir- gula hyemalis, Larus hyperboreus, Rissa tri- cumpolarly widespread and successful, where- dactyla, Sterna paradisaea, Uria lomvia); and as the Aleutian tern (S. aleutica) is a very re- six are panboreal-subboreal, widespread in stricted Beringean endemic, and its status their distribution—Oceanodroma leucorhoa needs to be exactly known. (extends far south), Histrionicus histrionicus, Almost one-third of the seabirds in this area Larus argentatus (widespread latitudinally), are alcids, a family centered in the North L. canus (also inland), Uria aalge, and Cep- Pacific and, more specifically, in the Bering phus grylle. Sea. Most species breed in enormous Seventeen species of marine birds are en- rookeries. Any impact of civilization is highly demic to Beringia: Anser canagicus, Poly- detrimental under such circumstances. Of the sticta stelleri, Somateria fischeri, Rissa brevi- four circumpolar species the two Uria guille- rostris, and Aethia pusilla (and the extinct mots (murres) are important. The dovekie Phalacrocorax perspicillatus); P. urile. Sterna [Alle alle) is a sparse pioneer of Bering Strait, aleutica, Aethia pygmaea, A. cristatella, and as is the black guillemot (Cepphus grylle) on Cyclorrhynchus extend westward to the Sea our side of the Arctic Sea. Its congener, the of Okhotsk, as do Brachyramphus breviros- pigeon guillemot (C. columba), is common and tris and Larus glaucescens, which also extend successful all the way to coastal central CaU- eastward; and Phalacrocorax pelagicus, fornia. Of the remaining 11 species, special at- Cepphus columba, Fratercula comiculata, and 170 M. D. F. UDVARDY

Lunda cirrhata are amphipacific species in on only the North American side—Phalacro- Beringia. corax auritus (also inland), P. penicillatus, Eight species of marine birds are associated Larus occidentalis (albeit barely), and Pty- with the North Pacific. Four are found on choramphus aleuticus. both sides of the ocean—Oceanodroma furcata, Brachyramphus marmoratus, Synthli- Finally, one species, Larus thayeri, is en- boramphus antiquus, and Cerorhinca mono- demic at the central Canadian Arctic, extend- cerata (very disjunct). The four others occur ing westward into the area here considered. CONFLICTS BETWEEN THE CONSERVATION OF MARINE BIRDS AND USES OF OTHER RESOURCES

Social and Economic Values of Marine Birds

David R. Cline' and C3nithia Wentworth U.S. Fish and Wildlife Service Anchorage, Alaska and Thomas W. Barry

Canadian Wildlife Service Edmonton, Alberta, Canada

Abstract

Throughout history, marine birds have provided tangible and intangible benefits to human societies. Unregulated exploitation of some species by explorers, mariners, and colonists led to the extinction of the great auk (Pinguinus impennis) and near extinction of others, including the Bermuda petrel {Pterodroma cahow) and the North Pacific albatrosses (Diomedea spp.). Marine birds continue to provide commercial, subsistence, recreational, scientific, and educational values to people of many nations, while playing critical roles in the economies of the world's oceans. Annual harvest of slender-billed shearwaters (Puffinus tenuirostris) known as "muttonbirds" in Australia, sooty tern (Sterna fuscata) eggs in the Caribbean, murres (Uria spp.) and eiders (Somateria spp.) in Greenland and the Soviet Union, and guano in Peru and Africa represent the principal commercial uses of marine birds and their products. Residents of the Faeroes Islands and thousands of native people in Greenland and arctic Canada and Alaska use various species for subsistence. The annual rituals of bird hunting and egg gathering are deeply ingrained in the sociocultural traditions of these peoples and continue to be important to their social welfare. Most countries of the world are currently providing at least some protection to their marine bird resources. However, the destruction of bird habitats by man's developments and the contamination of marine environments by industrial pollutants are posing increasingly serious threats to many species. If managed and used in accordance with scientific principles of sustained yield, some of the more abundant species of marine birds can continue to provide long-term social and economic benefits to man. Increasing numbers of people are expending considerable sums of money to reach marine bird viewing areas off the coasts of North American States and Provinces. PreUminary evidence indicates such nonconsumptive pursuits are contributing significant amounts of money to regional economies and helping businessmen earn a Uving. An accurate evaluation of both biological and economic impacts resulting from these nonconsumptive activities is urgently needed. The possibility of establishing an excise tax on designated outdoor recreational equipment appears to hold considerable potential for more adequately funding marine bird programs, as well as those for other nongame wildlife. Greater citizen involvement in sociopoUtical processes will, to a large extent, determine the success of marine bird conservation programs. Sound conservation legislation that insures adequate protection of habitat and provides for enlightened and innovative thrusts in conservation, education, research, management, and law enforcement will help insure the survival of all species of marine birds and, in turn, provide social and economic benefits to people across generations.

'Present address: National Audubon Society, 2 Marine Way, Juneau, Alaska 99801.

173 174 D. R. CLINE, C. WENTWORTH, AND T. W. BARRY

In its 17 March 1975 issue, Time magazine In this paper we examine some social and reported battalions of observers from all over economic indicators that are believed to the country flocking to Salisbury, Massachu- demonstrate people's growing awareness and setts, armed with telescopes, cameras interest in marine birds. These indicators in- dwarfed by huge telephoto lenses, sketch volve a broad spectrum of values and illus- pads, and binoculars. There, 1,500 strong the trate the critical need for adoption of a strong first weekend alone, they took up vigil along North American marine bird conservation the seawall of the Merrimack River. A local program. businessman circulated among the chilly bird- watchers with free coffee and hot chocolate, while handing out a pamphlet advertising his Historical Perspective restaurant. The cause of the commotion was the appear- Since earliest times, marine birds have ac- ance of a single, unassuming, pigeon-like sea- companied the evolution of human societies in bird called a Ross' gull (Rhodostethia rosea), coastal and insular environments of the almost never seen south of the Arctic Circle world. Their social value is in part recorded in and never before in the contiguous 48 States. kitchen middens of ancient campsites and Time stated that "for those who care about villages. From the time man first inhabited such matters the event was as electrifying as the seacoasts and ventured out in ships, the the descent of a Martian spaceship." company of seabirds has added life and in- Meanwhile, far above the Arctic Circle at spiration to what otherwise would be a bleak Point Barrow on the Arctic Ocean, Eskimo and desolate landscape. Fishermen long ago hunters probably puzzled at the strange ways learned to use seabirds to show them where of the white "birdmen," as they recalled the the rich fishing grounds were located, and the savory dishes Ross' gulls provided many of cries of birds were often used to guide them during the previous fall hunting season. mariners away from dangerous cliffs during This particular gull is considered a delicacy by foggy weather. the Eskimos, and the birds are actively At the time of the first contact with Euro- sought each year as they fly near shore during peans, native peoples of arctic Canada and their fall wanderings from Asian breeding Alaska reportedly took birds with bolas, grounds. snares, spears, arrows, and nets; they herded Perhaps this dichotomy of people's in- flightless waterfowl and gathered eggs as terests in a single species is indicative of the well. Brandt (1943) said that Alaskan broad spectrum of social and economic values Eskimos would have been destitute if eiders man derives from marine birds. Perhaps, too, {Somateria spp.) had not been available for it represents the challenge that wildlife pro- food and clothing, and Ekblaw (1928) believed fessionals, administrators, and citizen conser- the dovekie {Plautus alle) saved the polar vation leaders face in today's complex world Eskimo from extinction. in striving to sort out priorities in allocation Marine birds have often served as an emer- of such common property (amenity) resources gency food supply for explorers, sailors, and among beneficial users. others: according to Tuck (1960) "The ac- As with the Ross' gull, socioeconomic counts of early arctic explorers and marooned values of marine birds involve both consump- whalers describe many instances in which tive and nonconsumptive uses. Consumptive starvation was averted by eating murres" uses may provide socioeconomic values in the (Uria spp.). One burrowing petrel of AustraUa form of meat, eggs, oil, feathers, down, and was given the title "the bird of providence" guano. Cultural and recreational benefits may because it saved the lives of shipwrecked also be involved. Nonconsumptive uses bene- mariners and convicts when supply ships fit the tourist and recreation industries as from Sydney failed to reach them between well as providing less tangible social values, March and August of 1790 (Serventy 1958). such as esthetic appreciation and environ- Marine birds have also been taken because mental education and scientific study op- of the economic values of their feathers and portunities. oil. When economic overutilization has oc- SOCIAL AND ECONOMIC VALUES OF MARINE BIRDS 175

curred, entire species were sometimes totally been the primary cause of their destruction. destroyed. This in fact happened to the great Generally, the loss of a species because of un- auk {Pinguinus impennis). When Jacques Car- regulated harvest is no longer a matter of ma- tier visited the Funk Islands off Newfound- jor concern, because most countries of the land in May 1534, he and his crew filled world are providing at least some protection several barrels with great auks and salted for their marine birds. However, other factors them down for future consumption. So severe such as habitat destruction and contamina- was the slaughter in the next 3 centuries that tion of the marine environment by industrial the species became extinct in its known breed- pollutants are posing increasingly serious ing haunts, which originally extended from threats to many. Newfoundland through Greenland and Ice- land, to the Hebrides. The last one was killed at a stack rock off Iceland in 1884 (Lockley Social and Economic Indicators 1973). Economic indicators concerning Other species have been almost totally de- consump- tive uses of wildlife, including stroyed. Colonization of Bermuda by Spain in marine birds, are frequently misunderstood. the 17th century resulted in the near annihila- In a dollar- oriented and overconsumptive tion of the Bermuda petrel {Pterodroma society like ours, economic values are usually cahow) there. Ships' crews found the birds to seen as being in conflict with esthetic values. be fat and delicious, and they dried and salted "Eco- nomic use" usually conjures images of those that could not be eaten fresh. Today, up man's overutilization and, hence, only about 20 breeding pairs remain, and are long-term depletion of wildlife resources. However, under strict protection by the Bermudan gov- when speaking of economic use, it is impor- ernment (Lockley 1973). tant to distinguish between such overuse The North Pacific albatrosses {Diomedea and sustained-yield management. spp.) were nearly exterminated by Japanese Although both types of use have provided feather hunters near the end of the 18th cen- economic benefits over the years, overharvest tury. The short-tailed albatross {D. albatrus) that results in long-term resource depletion is was also nearly wiped out at its breeding colo- not usually the most or best economic in nies west of the Hawaiian Islands (Bourne use the long run; obviously a "harvest" cannot 1972). be sustained at a given level when the resource Other species that were carelessly exploited base is constantly being depleted. On the for their meat and plumage in the past, but other hand, when certain species of marine which have since regained their numbers, in- birds are used in accordance with principles of clude the fulmar (Fulmarus glacialis) on St. sustained yield, they can provide long-term Kilda Island in the North Atlantic; and the economic values to society in conjunction North Atlantic, South African, and Aus- with the social, esthetic, and intangible values tralian gannets (Morus bassanus, M. capen- that their preservation insures. Of course, for sis, and M. serrator) (Bourne 1972; Lockley many species esthetic values far outweigh 1973). In some instances entire breeding colo- economic ones derived through commer- nies of a species have been destroyed while cialization. others have survived. On the Abrothos Is- lands in western Australia, for example, large Commercial Uses nesting colonies of sooty terns {Sterna fuscata) and common noddies {Anous stolidus) Muttonbirds appear to have been wiped out on Rat Island by indiscriminate "egging" for food, whereas The muttonbird industry of Australia is an similar-sized colonies survive on other islands, excellent example of the commercial use of where they are now controlled by the marine birds on a sustained-yield basis. Fledg- Fisheries and Fauna Department (Serventy ling Tasmanian muttonbirds, or slender-billed et al. 1971). shearwaters {Puffinus tenuirostris), are com- Historically, it has probably been man's un- mercially harvested each year from their colo- regulated harvest of marine birds that has nies on islands of Bass Strait, mainly in the 176 D. R. CLINE, C. WENTWORTH. AND T. W. BARRY

Flinders Island group. Great quantities are also dried and salted for These muttonbirds are marketed as fresh or use in winter, Murre canneries at Upernavik salted "Tasmanian squab." Various by-prod- have suppUed southern cities with the frozen ucts, including oil, body fat, and feathers, are meat of about 25,000 to 30,000 murres an- also sold. In 1968, a total of just under one- nually. However, this commercial activity half million young birds were taken. Prices to would be prohibited by a proposed new Green- the producers varied from $12 to $14 (Aus- land game law (Salomonsen 1970). tralian dollars) per hundred salted birds and Banding has shown that about 22% of $16 per hundred fresh birds. Stomach oil Greenland's eider population, or about brought 75

Guano Subsistence Uses

Peruvian guano beds are currently being managed on a sustained-yield basis; the har- The use of marine birds and their products vest, as in the days of the Incas, depends en- does not have to be commercial to be eco- tirely on the amount of guano deposited each nomic. Economics is the science of the alloca- year. Conservation and management policies tion of scarce resources. Any resource, regard- have resulted in a steady increase in the less of whether it is bought or sold, has value amount extracted, from around 20,000 tons in to people and is therefore an economic com- 1900 to over tons in 200,000 1971 (Lockley modity. Thus, any society has an economy 1973). whether or not it uses cash, and when the The islands off south and southwest Africa meat, feathers, or oil of marine birds are used, are also commercial producers of guano. The the birds have economic value. The problem, annual yield from these breeding colonies of course, is that of trying to determine just averaged 3,971 tons in the 12-year period, what this value is when a cash medium does 1961-72. In 1969, guano brought 4.75 Rands not exist. (equivalent to $7.11) per 200-pound bag. One of the ways to estimate this value is to South African gannets are apparently de- assign impHcit gross dollar values to seabirds, positing guano that is worth twice as much as based on what it would cost to replace prod- the fish they consume to it (Jarvis produce ucts derived from them with store-bought 1971). items of a similar, or substitutable, nature (this is a gross rather than a net value because it does not include the cost of guns, ammuni- tion, transportation, etc., required to harvest and the Indirect Commercial Benefits process resource). There have been many occasions in the past when it would have been physically impos- Marine birds also play significant roles in sible to find substitutes for seabird products. the economies of the world's oceans, where In such cases, and where seabirds may well algae, invertebrates, fish, seabirds, mammals, have meant the difference between life and and man interact in complex ways. The bio- death, the economic value of the resource energetics and nutrient cycling in ocean eco- could be considered a plus infinity. systems is even less well understood than the There are probably few, if any, places in the contributions seabirds make to man's dollar world today where people would starve if they economies. could not obtain marine birds. However, there Sanger (1972) has conservatively estimated are still many situations where available sub- that in the subarctic Pacific region alone, stitutes are poor, or very expensive. And birds consume from 0.6 to 1.2 million tons of there are others where, even though the birds food and return from 0.12 million to 0.24 mil- are no longer necessary for economic survival, lion tons of feces each year. they are still very important in terms of socio- Marine bird excrement is especially rich in cultural traditions. According to Tuck (1960), nitrates and phosphates, which phytoplank- "Wherever a wild animal is important to the ton, the basis of ocean food pyramids, re- economy of a people, its capture and use be- quires. Marine birds then, at least to some ex- come part of the tradition of that people." tent, help to sustain the northern commercial, Thus, while economic values can be measured recreational, and subsistence fishing indus- in terms of substitutable store-bought foods, tries. The fisheries in turn sustain seals and social and cultural values cannot be. To force certain other mammals which are also essen- complete dependence on a people by flying in tial elements of northern subsistence and rec- foods from "Outside" is often socially intoler- reational economies. Thus, marine birds con- able because it tends to remove pride, a sense tribute economic benefits indirectly as well as of worth, and therefore the reasons for Uving. directly by serving as critical links in ecosys- Marine birds have served as important tem food chains (Tuck 1960). sources of food in the Faeroes Islands for cen- 178 D. R. CLINE, C. WENTWORTH, AND T. W. BARRY

turies, the puffin being unquestionably the dried or salted so that they can be used for most valuable. Williamson (1945) reported special holiday feasts during the winter. that in a good year the total puffin catch may Sometimes feathers are saved for the manu- be between 400,000 and 500,000. In addition, facture of parkas, ceremonial fans, and as many as 120,000 murres are snared or shot masks. In some areas of the Yukon Delta, annually by the Faeroese, and at least twice goose and duck down is still saved and used in that many eggs are taken and Tuck (1960) quilts that can be found in nearly every home. stated, "The economic necessity of 'fowling' In the spring 1975 issue of the catalog of a in the Faeroes has by virtue of long centuries Seattle, Washington, outfitter, down quilts of usage become part of the national life, af- for single beds were listed at $95. Thus, there fecting folklore and customs, and providing is a substantial cash savings by home manu- outlets for the sporting instinct inherent in facture of such items. the people." A Faeroese guidebook even sug- The Yukon Delta in western Alaska is the gests that its importance to the Faeroese cul- area where the use of marine birds is most ex- ture has been in no way diminished by the intensive and significant. Klein (1966) provided fluence of modern civilization. Current harvest data by village for the entire area and Faroese game laws appear to be effective in showed that, in general, geese were more im- assuring a sustained yield of marine birds portant than ducks, representing about two while guaranteeing their long-term survival. thirds of the take in both the spring and the Seabirds and their eggs constitute a small, fall. The average numbers of ducks (mostly but still very important, part of the total diet pintails. Anas acutus) and geese (primarily of the Eskimos and Indians living along the white-fronted geese, Anser albifrons); em- Arctic coast of the Northwest Territories and peror geese, Philacta canagica; cackling Alaska. In spite of the many changes occur- Canada geese, Branta canadensis minima;

ring in the North, there is, even for the wage and black brant, Branta nigricans, taken per earner, a strong psychological attachment to household were 77 by the Yukon River the land and sea and the free life it represents. villages, 69 by the Kuskokwim River and tun- In spring, the release from the long monoto- dra villages, and 94 by the Bering Sea coastal nous winter is marked by the rites of ratting, villages. Although eggs gathered by Yukon fishing, sealing, whaling, or marine bird hunt- River villagers averaged less than a dozen per ing and egg gathering, according to village household, Kuskokwim people took about 3 tradition. dozen and coastal people about 6.5 dozen on For those living off the land in such remote the average. Eggs of black brant and cackling coastal outposts as Sachs Harbor on Banks Canada geese were especially favored, but Island, Holman Island on the Mackenzie even those of small passerines were accept- Delta, Point Hope and Point Barrow in north- able. The average size of households for all ern Alaska, Inalik on Diomede Island in the areas was believed to be between 5.5 and 6.5 Bering Strait, or Hooper Bay on the Yukon- persons. Kuskokwim Delta, the spring marine bird A 1968 survey of waterfowl taken in the hunt represents a change of diet and activity. Mackenzie Delta region, made by the Cana- It offers opportunity to renew age-old tradi- dian Wildlife Service, showed an average take tions and continues a cultural bond among per household of about 70 birds, a figure com- those confined to jobs in the settlements—va- parable to that for the Yukon Delta. In the cationing and absenteeism from jobs and Mackenzie region, however, ducks were more schools are always highest during late May important than geese, representing about and early June. 60% of the harvest. Marine birds yield between a few grams and More recent data on Alaska waterfowl har- 2 kg of meat, depending on the species. vest per household is available for other Usually the birds are either consumed soon coastal regions. Data provided by two re- after they are taken or stored in an icehouse gional native corporations for the Joint Fed- for use throughout the summer. Most often eral-State Land Use Planning Commission the meat is cooked into a soup or stew with for Alaska in 1973 showed an average per- rice, noodles, and onions. A few birds may be household waterfowl harvest of 33 ducks and SOCIAL AND ECONOMIC VALUES OF MARINE BIRDS 179

geese for Kotzebue area villages, 68 for affix dollar values to every marine bird en- Norton Sound villages, 24 for northwest joyed by recreationists. Goldstein (1971), in Seward Peninsula villages, and 37 for St. his economic study of wetlands, found it im- Lawrence, Diomede, and King Island villages. possible to fix the value of the production and A 1974 subsistence survey carried out harvest of migratory waterfowl in Minnesota. jointly by the University of Alaska and the The amount of money spent by recrea- Bristol Bay Native Corporation showed that, tionists in seeking enjoyment from marine in 20 Bristol Bay villages, 57% of the house- birds does not measure the values they derive; holds harvested waterfowl. The average kill it measures only their costs to participate in was 32 birds per household. such ventures. The analogy that could be Eider ducks are the most important marine made is that the value of a diamond is equal to

birds taken by residents of Barrow, Alaska. the cost of mining it. Nevertheless, expendi- Johnson (1971) interviewed 31 adult hunters ture data for services and goods provided by with average kills of 88 birds per hunter. Bar- air-taxi and charter boat operators and mer- row people also take substantial numbers of chants selling bird guides, binoculars, and geese at Atkasook, a summer camp on the other outdoor recreational equipment are use- Meade River 80 miles southeast of Barrow. ful indicators in establishing the secondary or Point Hope, Alaska, villagers also favor indirect benefits of recreational activities as- eider ducks above all others. Pederson (1971) sociated with marine birds. indicated that each household that hunted The normal economic concept of net bene- took about 150 eiders in the summer of 1971. fits from marine bird recreation would include Each summer. Point Hope and Kivalina resi- only those accruing to individuals who pro- dents travel to the Cape Thompson and Cape vide goods and services to the recreationists, Lisburne cUffs to gather murre eggs. Both gross revenues minus the costs (Wollman Pederson (1971) and Kessel and Saario (1966) 1962; Pearse and Bowden 1969). This eco- showed an average harvest of 5 to 10 dozen nomic return, however, in no way measures di- eggs per household (equivalent in weight to 10 rect benefits of marine bird resources to the to 20 dozen chicken eggs). recreationists. To our knowledge, there is no available evi- Another important consideration in eval- dence to indicate that the number of migra- uating recreational use of marine birds is to tory birds taken in the North in spring and recognize that many of the nonparticipants fall is a significant factor in the survival of a either value the option of being able to take particular species. The birds are, however, a advantage of them in the future, or simply be- significant factor in the economy and culture lieve that the availability of such resources of the people of the Mackenzie Delta region benefits society (Stegner 1968). Such benefits and much of coastal Alaska. This not al- may are difficult, if not impossible, to quantify yet ways be true, for their social and economic may be exceedingly important due to the conditions are changing rapidly. uniqueness of the marine bird resource and be- the native With birthrate twice the national cause many decisions affecting it may prove average and with hunting technology improv- irreversible. ing yearly, the day will undoubtedly come Increasing numbers of bird enthusiasts when marine birds and other wildlife re- throughout North America are discovering sources are not able to withstand intensified the excitement and pleasures derived from harvest pressures without more regulation visiting marine bird rookeries. As pointed out and control. An obvious need exists for gov- by Sowl and Bartonek (1974), and as anyone ernment conservation agencies to work more can attest who has ever had the privilege of closely with the native people of northern re- watching the antics of tufted puffins (Lunda gions in conservation education and develop- cirrhata) near their colonies on a day when the ment of sound harvest regulations. sun is obscured and the air buoyant, watching seabirds is fun. Recreational Uses We have found that organizations and busi- nesses in practically every North American No attempt was made in this evaluation to coastal State and Province, from Nova Scotia 180 D. R. CLINE, C. WENTWORTH, AND T. W. BARRY

to Florida and Alaska to California, are busy manufacturers' shipments in 1972 was $157 scheduling boat or airplane excursions to miUion for camping equipment, $5 million for marine-bird viewing areas off their shores. binoculars, and $19.9 million for bird feed. The Alaska and Washington State ferry sys- Sales of wild bird feed have been increasing 5 tems have for years been providing passen- to 10% per year recently. These are all eco- gers opportunity to enjoy seabirds of the nomic indicators of recreation trends of which North Pacific coast. Audubon chapters in San enjoyment of marine birds is a part. Diego, Los Angeles, Monterey, Seattle, An- A major use of photographic equipment and other cities sponsor annual ex- chorage, and related products and services is in the natural cursions to seabird colonies. and scenic areas of the nation. Manufacturers' In 1975 a charter airline service in Anchor- shipments of photographic equipment, and age, Alaska, booked 530 people in 51 tours to photofinishing, were valued at $2.3 billion in fly to the Pribilof Islands in the Bering Sea to 1972. A 5% excise tax on these items would view the outstanding seabird and fur seal have generated nearly $118 milhon (Wildlife colonies there. Included in the bookings were Management Institute 1975). three National Audubon Society Interna- Since inadequate funding plagues most non- tional Ecology Workshops, the Massachu- game management initiatives, the Wildlife setts Audubon Society, the National Wildlife Management Institute (1975) recommended Federation, and Canadian Nature Federation. that Congress authorize a matching grant-in- Participants paid from $1,500 to $2,000 for aid program to benefit nongame fish and wild- these tour packages to Alaska. At $300 to life. Funds would be obtained from new manu- $380 per person, depending on the length of facturers' excise taxes on designated outdoor the excursion, the air charter service grossed recreational equipment to initially yield at about $160,000 from these tours (Reeve Aleu- least $40 million annually. tian Airways, personal communication). Fairweather Outings, a small cruise busi- The Executive Committee of the Interna- ness based in Sitka, Alaska, takes people on tional Association of Game, Fish and Conser- wilderness excursions in the west Chichagof- vation Commissioners and the Council of the Glacier Bay area of the southeastern part of Wildlife Society have already endorsed model the State. The seabird rookeries are one of the legislation for a State program for nongame principal attractions for the 90 people taking wildlife conservation (Madson and Kozicky these trips each year. Over one-third of the 1972). We urge that these proposals be given serious clientele has been from outside Alaska; thus consideration in terms of future funding of bird conservation in their dollars are new dollars to the State's marine programs economy. Fairweather Outings grossed about North America. $11,000 in 1974 (Charles Johnstone, personal It is encouraging to note that several communication). States, including Washington, Oregon, and These examples illustrate how seabirds, California, have recently initiated nongame both directly and indirectly, help small wildlife programs that have resulted in sub- coastal businessmen earn a living. It is also stantial benefits to their citizens. The Cali- important to recognize that the multiplier ef- fornia legislature, for example, enacted a law fects generated by the expenditures in all of in 1974 to provide a means for individuals and the above examples ripple through the re- organizations to donate funds for supporting gional and State economies. nongame species management. The California Despite the great social and economic sig- Department of Fish and Game has increased nificance of such activities along our coasts, its nongame staff and appointed a citizen apparently no attempt is being made to deter- Nongame Advisory Committee to help de- mine the number of people involved in such velop and implement nongame programs. pursuits and how much they are spending. A Because most species of marine birds are study of the phenomenon would undoubtedly not hunted by sportsmen in North America, produce startling results. this increased emphasis on nongame species The Wildlife Management Institute (1975) may eventually benefit research and manage- revealed that the national estimated value of ment programs for seabirds substantially. SOCIAL AND ECONOMIC VALUES OF MARINE BIRDS 181

Scientific Research influence of the professional lobbyists and public relations operators hired to further the Even now, marine-bird research studies and special interests of their cUents." Mr. Peter- inventories require the expenditure of several son further emphasized that government million dollars annually along our coasts. In thrives much better on citizen concern and at- Alaska a multimillion dollar Federal effort tention than on indifference and neglect. has been initiated to assess the environmental Therefore, it is highly significant that the risks of developing offshore petroleum poten- Pacific Seabird Group has many nonprofes- tial in the Gulf of Alaska and five other key sional, as well as professional, members and areas of the State. These areas represent 60% that the 1975 International Symposium on of the nation's total continental shelf and sup- Conservation of Marine Birds of Northern port some of the largest marine-bird popula- North America had strong citizen involve- tions in the world. The program to examine ment and participation. As everyone recog- life-forms and the physical environment of the nizes, nothing works in government unless petroleum lease areas will require 4 to 5 years people, be they doctors, lawyers, college pro- to complete. Approximately $1.5 million has fessors, students, environmentaUsts, or In- been allocated to conduct an environmental dian chiefs, make it work. assessment of marine bird resources in the Educators must upgrade training in envi- first 18 months alone. ronmental sciences so that an environmental The U.S. Fish and Wildlife Service is spend- awareness (conservation ethic) is instilled in ing about $40,000 to determine the seasonal young people. In this regard, an Alaskan bird occurrence, density, and distribution of study program proposed for Alaska schools marine birds in coastal waters adjacent to by J. G. King, Jr., of the U.S. Fish and Wild- new national wildlife refuges in Alaska being life Service in 1962 deserves close scrutiny. proposed pursuant to the Alaska Native This highly innovative and practical environ- Claims Settlement Act of 1971, and almost mental education proposal apparently arrived $200,000 to study and manage migratory before its time, for nothing was ever done to

birds—including marine birds—on existing institute it. Possibly, now would be a good refuges. time to give it a closer look. Although generated by external events (including requirements pursuant to the Na- tional Environmental Policy Act of 1969) Conclusions rather than by the resources themselves, these expenditures at least indirectly reflect a Success in more adequately recognizing and social concern for the welfare of marine birds. using social and economic indicators to strengthen and broaden seabird programs will depend on the ability of the resource manage- Citizen Involvement ment agencies to blend the old with the new. (Social Indicator) It is obvious to most that new alignments, programs, authorities, and sources of funds Another encouraging aspect of seabird con- are needed, but by themselves, they will not servation and its meaning to society is the in- be enough to overcome the continuing mas- creasing involvement of citizens in the issue. sive losses of wildlife habitat due to popula- Although agencies have not been as respon- tion growth and technological impacts result- sive as many would like, administration of ing from various developmental programs. government at all levels has been shaken and No marine bird programs will be successful stimulated by citizen participation. As without a strong political base. If this is to be Russell W. Peterson, Chairman of the Council assured, resource agencies must be more re- on Environmental Quality, has stated, "Citi- sponsive to the needs of both consumptive zen action is the essence of democracy. Citizen and nonconsumptive users and involve them movements should be encouraged and ex- in their programs from early in the planning panded. The involvement of people is neces- process. Because marine birds and the natural sary to counterbalance the disproportionate environments they inhabit are jointly valued 182 D. R. CLINE, C. WENTWORTH, AND T. W. BARRY

over time and are jointly owned, it is impor- and prospects. Trans. N. Am. Wildl. Nat. Resour. tant to ask not only what is efficient from the Conf. 34:283-293. Pederson, S. 1971. Status and trends of subsistence point of view of the present generation but resource use at Point Hope. Pages 37-89 in B. also is equitable across generations. what MacLean, ed. Point Hope project report. Univ. of Alaska, Fairbanks. References Salomonsen, F. 1970. Birds useful to man in Green- land. Pages 169-175 in Productivity and conser- Belopol'skii, L. O. 1961. Ecology of sea colony birds vation in northern circumpolar lands. Interna- of the Barents Sea. (Transl. from Russian.) Israel tional Union for Conservation of Nature and Program for Scientific Translations, Jerusalem. Natural Resources, Morges, Switzerland. 346 pp. Sanger, G. A. 1972. Preliminary standing stock and Bourne, W. R. P. 1972. Threats to seabirds. Int. biomass estimates of seabirds on the subarctic Counc. Bird Preserv. Bull. 11:200-218. Pacific region. Pages 589-611 in A. Y. Yakenouti Brandt, H. 1943. Alaskan bird trails: adventures of et al., eds. Biological oceanography of the North an expedition by dogsled to the delta of the Pacific. Idemitsy Shoten, Tokyo. Yukon River at Hooper Bay. Bird Research Serventy, D. L. 1958. Mutton-birding. Pages 233- Foundation, Cleveland, Ohio. 464 pp. 234 in A. H. Chisholm, ed. The Australian En- Ekblaw, W. E. 1928. The material response of the cyclopedia, Vol. 6. Angus and Robertson, Syd- polar Eskimo to their far arctic environment. ney. Ann. Assoc. Am. Geog. 17(4):147-195. Serventy, D. L. 1969. Mutton-birding. Pages 53-60 Goldstein, J. H. 1971. Competition for wetlands in in K. Taylor, ed. Bass Strait Australia's last fron- the Midwest: an economic analysis. Resources for tier. Australian Broadcasting Company, Sydney. the Future, Inc., Washington, D.C. 105 pp. Serventy, D. L., U. Serventy, and J. Warham. 1971. Jarvis, M. J. F. 1971. Interactions between man Seabird conservation problems in Australia. and the South African gannet. Biol. Conserv. Pages 40-44 in D. L. Serventy, U. Serventy, and 3(4):269-273. J. Warham. The handbook of Australian birds. Johnson, L. L. 1971. The migration, harvest and im- A. H. and A. W. Reed, Sydney. portance of waterfowl at Barrow, Alaska. M.S. Sowl, L. W., and J. C. Bartonek. 1974. Seabirds: Thesis. Univ. of Alaska, Fairbanks. 87 pp. Alaska's most neglected resource. Trans. N. Am. Kessel, B., and D. Saario. 1966. Human ecological Wildl. Nat. Resour. Conf. 39:117-126. investigations at Kivalena. Pages 969-1039 in Stegner, W. 1968. The meaning of wilderness in N. J. Wilimovsky and J. N. Wolfe, eds. Environ- American civilization. Pages 192-197 in R. Nash, ment of the Cape Thompson region, Alaska. ed. The American environment: readings in the U.S.A.E.C, Div. Tech. Inf., Oak Ridge, Ten- history of conservation. Addison-Wesley Publish- nessee. ing Co., Reading, Massachusetts. Klein, D. R. 1966. Waterfowl in the economy of the Tuck, L. M. 1960. The murres. Ottawa, Can. WUdl. Eskimos on the Yukon-Kuskokwim Delta, Ser. 1. 260 pp. Alaska. Arctic 19(4):319-335. Wildlife Management Institute. 1975. Current in- Lockley, R. M. 1973. Man and seabirds. Pages 74-90 vestments, projected needs, and potential new in R. M. Lockley. Ocean wanders: the migratory sources of income for nongame fish and wildlife seabirds of the world. Stackpole Books, Harris- programs in the United States. Wildlife Manage- burg, Pennsylvania. ment Institute, Washington, D.C. 55 pp. Madson, J., and E. Kozicky. 1972. A law for wild- Williamson, K. 1945. The economic importance of life: model legislation for a State nongame wild- seafowl in the Faeroes Islands. Ibis 87:249-269. life conservation program. Winchester-Western Wollman, N., chairman. 1962. The value of water in Division, Conservation Department, East Alton, alternative uses, with special application to water IlUnois. 20 pp. use in the San Juan and Rio Grande basins of Pearse, P. H., and G. K. Bowden. 1969. Economic New Mexico. Univ. of New Mexico Press, Albu- evaluation of recreational resources: problems querque. 426 pp. Resource Development Along Coasts and on the Ocean Floor: Potential Conflicts with Marine Bird Conservation

Donald E.McKnight Alaska Department of Fish and Game Subport Building Juneau, Alaska 99801 and

C. Eugene Knoder National Audubon Society Lakewood, Colorado

Abstract

Although development of hard mineral resources, expansion of the timber industry, and resultant increases in human pressures along the North Pacific and Arctic coasts will ultimately adversely affect northern marine bird populations, current and proposed activities of the petroleum industry are the most immediate threat to marine birds. The Federal Government's recently announced plans for oil and gas leasing on the Pacific outer continental shelf eclipse the significance of North Slope and Cook Inlet oil developments. Within a few years, onshore storage facilities and supertankers plying these waters will undoubtedly result in widespread chronic and localized catastrophic contamination of northern marine ecosystems. Coastal and offshore waters south of the reaches of the seasonal ice pack are tremendously productive, supporting a diverse wealth of bird life throughout the year. Because these ecosystems are relatively stable and the impact of temporal oscillations on the physical environment is not as great as in the Arctic, birds in these areas are probably least susceptible to man's influence on a long-term basis. Avifaunal associations of the Arctic are less diverse and have shorter food chains than more southerly ones; consequently they are more susceptible to environmental perturbations. Slow growth and maturation rates of arctic species and resultant prolonged population recovery periods further aggravate this situation. Available knowledge of northern seabirds and their environmental requirements is in inverse relation to the latitude at which they are found and to the ecological stability of the ecosystems involved. Arctic bird associations and their fragile environments are least understood, but are doubtless the most vulnerable to the detrimental effects of man-caused environmental degradation. The paucity of knowledge about them limits the possibility of predicting the consequences of petrochemical exploitation and thereby safeguarding against potential problems. Existing technology and support system capabilities of the oil industry are more poorly defined for arctic areas, further compounding this problem. Regardless of information amassed in the future and precautionary measures taken during exploitation of arctic petroleum reserves, the potential for disastrous and perhaps irrecoverable losses to northern marine bird species and populations is great. Losses of major magnitude could appreciably alter the productivity of northern marine ecosystems.

183 184 D. E. MC KNIGHT AND C. E. KNODER

Although the coastal waters of the north- less, environmental impact statements on western United States and western Canada proposed developmental programs in the support a plenitude of marine life, including North still raise more questions than are marine birds, relatively little is known about being answered. Attempts are being made to these ecosystems. Sustained interest in quan- apply available information on oil spills, hu- titative aspects of this area's marine bird man disturbance, and other aspects of envi- populations has developed only within the ronmental degradation gathered from experi- past few years. As Sowl and Bartonek (1974) ences in other areas to expected problems in indicated, seabirds are the most visible com- northern environments, but one must realize ponent of a marine ecosystem and, at the that much of the information gained from ex- same time, they are the least understood. perience elsewhere is not applicable to these Management information has been hap- areas. It is realistic to assume that, until de- hazardly gathered, and because seabirds oc- velopment-related problems occur in the cur in incredibly large numbers in north North, biologists cannot estimate the magni- Pacific and arctic waters, it has been con- tude or ecological dimensions of their effects. venient to assume that, in the absence of However, existing knowledge of ecological problems, systematized data gathering and "laws" and of the biology of some species pro- analysis were unnecessary. vides the base for limited predictive efforts. It is the purpose of this paper to describe The sudden emergence in the late 1960's of significant current and proposed resource de- Alaska and portions of northwest Canada as velopment along the coasts and the ocean potential major oil production areas has floors, to summarize existing knowledge of changed this situation dramatically. Ongoing the ecology of marine birds in these areas, and and planned petroleum development in the to identify potential conflicts with marine North and the concurrent expansion of hard bird conservation. We hope that identification mineral extraction and logging activities now of these problems will provide impetus to data threaten to adversely affect these marine bird gathering and management programs neces- resources. Alaska's human population, which sary for conservation of these valuable numbered only slightly over 400,000 in 1975, resources. will probably double within the present decade. Doubtless, increased numbers of people, oriented toward mineral and other re- The Region and its Avifauna source exploitation rather than toward traditional wildland values, will compound these The region discussed here encompasses problems. Pressures on State and local gov- nearly half of the United States and Canadian ernments for increased services necessitated coastlines, extending from Washington to the by increasing populations will require addi- eastern edge of the Northwest Territories. tional expenditures. In Alaska, at least, these Alaska alone has two-thirds of the United demands are being imposed before revenues States' continental shelf (Bartonek et al. from minerals become available. This necessi- 1971). This region's marine and estuarine tates additional oil leases, timber sales, and waters are some of the most productive in the other means for obtaining immediate funding, world and support a diverse wealth of bird life thereby adding to the acceleration and ir- throughout the year. Sanger (1972), for reversibility of industrial expansion into the example, estimated total summer standing North. stocks of some 21 million birds in an area ap- This atmosphere of change has spawned proximating the outer continental shelf from major government- and industry- supported the Bering Strait south along the coasts of programs to broaden knowledge of northern the Aleutian Islands and North America to marine ecosystems, including their avifauna. central CaUfornia. Sanger and King (this There has been a recent flurry of pubhcations volume), to whom more data were available, on seabird populations and biology and a pro- revised this estimate upward to 45 million. liferation of papers stressing the need to learn Bartonek et al. (1974) provided estimates of more about the biota of this area. Neverthe- year-round standing stocks of 27 million birds RESOURCE DEVELOPMENT ALONG COASTS 185

in the Bering Sea alone. cellariids— mostly slender-billed shearwaters North and east of the Bering Strait, popula- (Puffinus tenuirostris) and sooty shear- tion estimates of the bird fauna are less com- waters—made up 94% of the biomass. Procel- plete. Swartz (1966) estimated, however, that lariids, including fulmars, larids (largely glau- seabird populations of five colonies in the vi- cous-winged gulls, Larus glaucescens), black- cinity of Cape Thompson in the Chukchi Sea legged kittiwakes (Rissa tridactyla), and large exceeded a total of 420,000 breeding birds in alcids, including the tufted puffin (Lunda cirr- 1960. Information provided by Bartonek and hata), made up 87% of the winter biomass in Sealy (this volume) indicates that large colony this domain (Sanger 1972). complexes at Cape Lisburne and Little Dio- Although most of the arctic waters, includ- mede Island each number, in aggregate, over ing the Bering, Chukchi, and Beaufort seas,

1 million breeding birds, mainly alcids, kitti- are unavailable to birds during the winter be- wakes (Rissa spp.), gulls (Larus spp.), fulmars cause of pack ice, they seasonally host an avi- (Fulmarus glacialis), and cormorants (Phala- fauna dominated by colony nesters, such as crocorax spp.). Although the Chukchi Sea common and thick-billed murres (Uria aalge coast north of Cape Lisburne has no rocks and U. lomvia), and tundra nesters, such as suitable for cliff-nesting seabirds, large num- oldsquaws and eiders. In far northern waters, bers of tundra-nesting species use the inshore sea ducks (mainly eiders and oldsquaws), red waters as a migratory pathway, and many phalaropes (Phalaropus fulicarius), and gulls nonbreeding cliff nesters summer in these are the predominant species. waters (J. M. Scott, comments by Pacific Sea- Intertidal areas throughout the Alaska, bird Group on U.S. Department of the Inte- British Columbia, and Washington coasts rior Draft Environmental Statement 74-90). support characteristic assemblages of shore- According to Scott, sea ducks and gulls are birds, including the black oystercatcher the most numerous birds in the Beaufort Sea. (Haematopus bachmani), rock sandpiper Observations by Thompson and Person (1963) (Erolia ptilocnemis), wandering tattler of an estimated 1 million eiders, mostly king (Heteroscelus incanum), surfbird (Aphriza vir- eiders (Somateria spectabilis) and Pacific gata), and black turnstone (Arenaria melano- eiders (S. mollissima), passing over Point Bar- cephala) as reported by J. M. Scott (com- row en route to molting areas, reflect the num- ments by Pacific Seabird Group to U.S. De- bers involved. Oldsquaws (Clangula hyemalis) partment of the Interior Draft Environmental use coastal waters of the Beaufort Sea for Statement 74-90). Perhaps the greatest con- postbreeding wing molts; Bartels (1973) esti- centrations of shorebirds in this whole region mated their numbers at nearly 400,000 in the occur during spring and fall migrations in fall and perhaps more during the molting Prince William Sound. The tremendous num- period. Shorebirds, jaegers (Stercorarius bers of migrating birds using these tidal and spp.), gulls, and terns, most of which use marsh areas are hard to imagine, but densities coastal waters at some time during the sum- of up to 250,000 shorebirds per 259 hectares mer season, swell bird numbers by several mil- (ha) on portions of the more than 51,820-ha lions in this area (Arctic Institute of North tidal flats of the Copper River Delta have America 1974). been recorded (I sleib and Kessel 1973). As indicated by Sanger (1972), the seabirds Although this region's avifauna is remark- inhabiting coastal areas south of Bering able from the numerical standpoint, it is im- Strait are mainly members of the Procellarii- portant to remember also that some of its dae in summer and Alcidae in winter. Sooty species are Umited in distribution to this area. shearwaters (Puffinus griseus) are the preva- According to Bartonek et al. (1971), Alaska is lent summer species and ancient murrelets the only known breeding area for black turn- (Synthliboramphus antiquus) and marbled stones, bristle-thighed curlews (Numenius murrelets (Brachyramphus marmoratus) are tahitiensis), surfbirds, western sandpipers the most abundant winter species. Sanger's (Ereunetes mauri), and Kittlitz's murrelets central subarctic domain (offshore waters in- (Brachyramphus brevirostris). Several water- cluding the Gulf of Alaska) had a different fowl species, including the dusky Canada species composition. During the summer, pro- goose (Branta canadensis occidentalis), cack- 186 D. E. MC KNIGHT AND C. E. KNODER

ling Canada goose {B. c. minima), Aleutian field and offshore fields in the Upper Cook Canada goose (B. c. leucopareia), and Aleutian Inlet basin have been producing oil for nearly common teal (Anas crecca nimia) nest only in a decade. The discovery of petroleum reserves Alaska coastal areas (Bartonek et al. 1971). on Alaska's North Slope and Canada's Mac- Izembek Lagoon on the Alaska Peninsula an- kenzie River Delta is common knowledge, and nually hosts the entire population of black a pipeline has been constructed to transport brant, Branta nigricans (Hansen and Nelson Alaska oil to a tanker facility at Valdez in 1957), and many other waterfowl, seabird, and Prince Wilham Sound. Alternative proposals shorebird species nest or live in this region in to pipe North Slope natural gas along the numbers important to their worldwide existing corridor to a facihty in Prince Wil- welfare. liam Sound or to build a new pipeline to take this gas to existing fields, and a planned pipeline on the Mackenzie River Delta and south Current and Planned through Canada, are being considered. Con- Resource Development struction of a gas liquefaction faciUty in Prince WiUiam Sound and tanker traffic The immense nonrenewable resource wealth through the Sound and the Gulf of Alaska are of Alaska and other arctic regions has re- potential ramifications of an Alaska gas pipe- mained virtually unrecognized or unexploited Une. until recently because of the availability of As McKnight and HiUker (1970) and Barto- these resources in more accessible locations. nek et al. (1971) pointed out, the greatest As supplies have diminished or been ex- potential problem for marine bird populations hausted elsewhere and demands have in- from North Slope oil will be associated with creased, however, it has become economically the operations of the Alyeska Pipeline sys- feasible or necessary to tap supplies in less-ac- tem's terminal at Valdez. Oil storage and cessible regions. For this reason, the petro- ship-loading faciUties at this port and heavy leum industry has recently expanded its ex- tanker traffic through Prince William Sound ploratory efforts in the far North with well- represent a pollution source that could result known success. Deposits of metalhc ores, in significant seabird and waterfowl mortali- coal, and other raw materials to feed industry ties. Certainly, development of gas liquefac- have likewise been discovered and plans de- tion facilities in the Sound, with inherent in- vised for their extraction and sale. Pressed creases in human populations and tanker with decreased availability of commercial tim- traffic, would compound this potential ber elsewhere, the logging industry has simi- problem. larly begun to broaden its efforts into Alaska. Expansion of industrial activities into the Although future impacts from existing North is proceeding at a rapidly accelerating petrochemical developments are cause for pace, and these industries, their associated concern, the Federal Government's recently support industries, and expanded human announced plans for oil and gas leasing on the populations are having and will continue to Pacific outer continental shelf (Fig. 1) echpse have unprecedented impact on these marine the significance of North Slope and Cook Inlet ecosystems, including their avifauna. oil developments. It now appears the Gulf of Alaska is the most favorable area of the outer continental shelf for oil and gas production Petroleum Development (Council on Environmental Quahty 1974). This area, covering more than 10.3 million ha, The existence of potentially marketable dil has already been subjected to extensive seis- and gas deposits in Alaska has been recog- mic investigations, and estimates of its undis- nized since the early 1900's, but it was not covered, economically recoverable crude oil until the Swanson River, Alaska, oil field was and natural gas resources range from 3 to 25 discovered in 1957 and later developed that billion barrels and 15 to 30 trilUon cubic feet, the Arctic entered the modern era of oil de- respectively (Council on Environmental velopment (McKnight and Hiliker 1970). This QuaUty 1974). RESOURCE DEVELOPMENT ALONG COASTS 187

I 1 / 1 \ 180 170 160 150 140

Fig. 1. North Pacific, showing portions of the outer continental shelf being considered for gas and oil leasing by the Federal Government (vertical hatching) and areas leased or proposed for leasing by the State of Alaska (cross hatching).

Kinney et al. (1970) reported that in Cook the widespread and massive nature of petro- Inlet, Alaska, an estimated 0.3% of the oil chemical developments in the Arctic planned produced and handled in offshore platform for the next 2 decades (Fig. 1). Proved crude wells is spilled. Several routine offshore opera- oil reserves are less than 1 billion barrels and tions result in discharges of oil and other natural gas reserves are less than 2 trillion materials into water, and, unlike accidental cubic feet in Cook Inlet, but it appears that spills, the probability of their occurrence is undiscovered recoverable oil and gas re- 100% (Council on Environmental Quality sources may be much greater (Council on En- 1974). During drilling operations, cleaned vironmental Quality 1974). There are also in- drilling mud and drill cuttings are discharged dications that known onshore oil reserves overboard. DrilHng mud may consist of such along Alaska's northwest coast will soon be substances as bentonite clay, caustic soda, or- opened for development by the Arctic Slope ganic polymer, proprietory defoamer, and Regional Corporation, landowners in the area ferrochrome Ugnosulfate. Waters from geo- as a result of the Native Land Claims Act of logical formations are often produced and dis- 1971. This group is at least considering the charged into the sea while the wells are in pro- transportation of these petroleum products to duction. These waters may be fresh or saUne, market in tankers, from an open-water port in and often contain small amounts of oil. All of the Chukchi Sea— thereby adding to the these pollutants increase the adverse effects tanker traffic in northern waters. of offshore oil production, and when potential spills are also considered, the ultimate impact Hard Mineral Resource Development on the marine ecosystem may be substantial.

The State of Alaska has already leased off- As indicated by Bartonek et al. (1971), there shore sites in Kachemak Bay, and present has been renewed interest in opening up considerations for future leases in the lower Alaska's hard mineral resources to economic Cook Inlet and Beaufort Sea further reflect development as new transportation routes 188 D. E. MC KNIGHT AND C. E. KNODER

and modes have been developed. Plans are estuarine environments for brood rearing and being completed to develop the Bering River wintering. This essentially nonmigratory coal field, with the eventual goal of exporting goose (Hansen 1962) may be particularly vul- coking coal to Japan. Although mining opera- nerable to logging activities in these areas. tions might ultimately affect freshwater envi- Similarly, recent evidence indicates that ronments to the detriment of several water- marbled murrelets may nest in large conifer fowl species, including the trumpeter swan trees adjacent to the coast, from northwest- {Olor buccinator), the chief cause for concern ern CaUfornia to northern southeastern will be additional freighter traffic through Alaska (Harris 1971; Savile 1972). If this is Prince William Sound. Similar plans to de- true, logging may eventually greatly restrict velop Klukwan and Snettisham iron deposits the breeding of this numerically important in- in southeastern Alaska for the use of Japa- habitant of northern coastal waters. nese industry (Bartonek et al. 1971) may result in the imposition of further traffic in Assessment of Resource Alaska shipping lanes. Development and Potential Plans are under way to strip-mine coal deposits in the Beluga field near the west side of Conflicts with Marine Bird Cook Inlet and transport a coal slurry via Conservation pipeline to a thermal electric generation plant opposite Anchorage on the Inlet. Impact on Although extraction of hard mineral re- tidal areas may be minor, but thermal pollu- sources, expansion of the timber industry, tion of the waters is a possibility. and resultant increases in human pressures Development plans for tin and tungsten de- along North Pacific and Arctic coasts will posits in the Lost River area of Alaska's ultimately affect northern marine bird popula- Seward Peninsula are under way after several tions, current and proposed activities of the years of faltering starts and stops. These ac- petroleum industry pose the most immediate tivities and possible extraction of gold lying threat to marine birds. Chronic degradation of offshore from Nome may ultimately have estuarine and marine coastal waters by log- some effect on these coastal areas. Methods ging wastes, pulp mill and sewage effluents, for recovering gold, regardless of the type, and bilge oils is an insidious process, the im- would disrupt marine and estuarine environ- pacts of which will be difficult, at best, to ments used by marine birds (Bartonek et al. quantify. Results of a major oil spill or even 1971), and transportation of ores would also low-level contamination of marine ecosystems increase freighter traffic in the Bering Sea. with oil will be more apparent, however. For this reason, and the fact that the industry is Timber Resource Development expanding rapidly into the North, most of this discussion will be directed at the impacts of Although the timber industry has long been oil development on northern marine birds. established along the coast from Washington Potential sources of adverse environmental north through southeastern Alaska, timber degradation affecting these birds resulting harvests are rapidly expanding on U.S. Forest from oil and gas exploration, development,

Service lands in Alaska. The impact of this in- and production include: (1) oil discharges into dustry is principally on terrestrial ecosys- marine waters, both chronic and catastrophic, tems, but certainly log rafting in estuarine (2) gravel excavation and dumping in coastal areas, disposal of wastes from pulp mills, and areas, (3) seismic activities, (4) discharge of freighter traffic transporting wood pulp or drilUng mud and drill cuttings into marine logs to Japan and west coast markets con- waters, including toxic heavy metal consti- tribute to the chronic degradation of marine tuents of driUing mud, (5) disturbance result- bird environments. Recent, meager studies on ing from petrochemical activities, and (6) in- the Vancouver Canada goose (Branta cana- creased human populations resulting in inter- densis fulva) in southeastern Alaska have ference with critical life processes and in- pointed out the importance to this species of creased hunting of game species. Each source coastal timber stands for nesting and of environmental change will vary by latitu- RESOURCE DEVELOPMENT ALONG COASTS 189

dinal and seasonal factors in their effects vail (Ashmole 1971). Arrival of these birds upon the birds. We consider herein only generally coincides closely with the earUest coastal and ocean floor developments and availability of nesting habitat and food (Wil- their anticipated generalized impacts on liamson et al. 1966). Migration, molting, and populations. reproduction place tremendous stresses on Although this is a discussion of "northern" these birds, and as a result, arctic-nesting marine birds, it is important to remember species tend to reproduce less often and at that we are considering a diverse avifauna older ages than do those of more temperate re- existing in an environmental gradient from gions (Ashmole 1971). temperate to polar regions. In general, the In spite of these adaptations, arctic bird more southerly portions of this marine envi- species tread a thin line between extinction ronment are characterized by a greater diver- and survival, and natural disasters take a sity of species, more complex food chains, and heavy toll. Bailey and Davenport (1972) re- a resultant greater stability (Dunbar 1968). ported a massive mortality in a pelagic popu- Arctic marine ecosystems, on the other hand, lation of common murres in Bristol Bay, are characterized by numerical dominance by Alaska, during April 1970. They felt that this a few species, relatively simple food chains, disaster, resulting in the death of probably and an inherent instability or fragility (Dun- 100,000 or more birds, most likely resulted bar 1968). According to Dunbar, arctic sys- from starvation precipitated by severe tems are regulated primarily by temporal os- weather. Barry (1968) reported a similar loss cillations in the physical environment, where- to starvation of about 100,000 eiders along as biological interactions (e.g., competition, the Beaufort Sea coast during the extremely predation) are considered more significant in cold spring of 1964. Observers along Alaska's the maintenance of temperate and tropical Beaufort Sea reported finding eiders and old- ecosystems. squaws dead and dying from the effects of Because of their relative instability, arctic cold weather in 1970 (Bartonek et al. 1971). It ecosystems are more susceptible to alteration is readily apparent that the tenuous existence by extreme environmental perturbation, into which these birds have evolved leaves either natural or man-imposed (Burns and them particularly vulnerable to the man-in- Morrow 1973). Slow growth and maturation duced stress of developments during the arc- rates of the avian constituents of these eco- tic summer. systems and resultant long recovery periods (Ashmole 1971) further aggravate this Direct Effects of Oil Pollution situation. Regardless of their seasonal availability, The most obvious, and perhaps the most these arctic waters constitute some of the disastrous consequence of petrochemical de- most productive areas for seabirds in the velopment on northern marine bird popula- western hemisphere (Bartonek et al. 1974). tions is that of a major oil spill or a well blow- Upwelling, nutrient-rich waters, combined out into marine waters. Although temperate with intense and prolonged incident radiation, and tropical waters are apparently able to as- result in lush phytoplankton "blooms" that similate oil spills and chronic pollution from form the foundation of relatively simple but petroleum and its products (Nelson-Smith numerically strong plant and animal com- 1972), this has not been demonstrated to be munities (Ashmole 1971). A relatively small true for arctic waters. In fact, studies in the number of avian species have evolved to take Beaufort Sea have shown that the bacteria advantage of this seasonally available food that degrade oil do not use hydrocarbons at supply, and the ability to migrate to lower the ambient temperatures of the Arctic latitudes in winter is a characteristic of most (Glaeser and Vance 1971). Therefore, a large arctic-nesting species. Because summers are oil spill in the Arctic could persist for many short in arctic regions, early arrival and a syn- years. As demonstrated by Campbell and chronous breeding schedule are necessary to Martin (1973), the diffusion and transport enable the young to leave the breeding mechanisms generated by the pack-ice dy- grounds before severe weather conditions pre- namics of the Beaufort Sea and the slow rate 190 D. E. MC KNIGHT AND C. E. KNODER

of oil biodegradation under arctic conditions tion was estimated at 100,000 in 1960, and in would combine to diffuse an oil spill over the two separate but not isolated incidents 1 to sea and eventually deposit oil on the ice sur- 2% of this number were known to have been face. This, in turn, would lower the natural al- killed by oil. Unknown but considerable num- bedo over a large area and melt the ice in the bers were uncounted or were lost at sea. area of the spill. This pack ice supports an Colony nesters, including puffins {Fratercula under-ice community which is an important arctica), razorbills {A lea torda), and murres in food source for phalaropes, jaegers, gulls, the southerly portions of the North Sea are terns, and other seabirds (Watson and Divoky declining rapidly (Nelson-Smith 1972). 1972). Puffins, which numbered 100,000 on Annet in As indicated by Nelson-Smith (1972) many the Scilly Isles in 1907, were reduced to 100 investigators have stated that a spot of oil birds by 1967; by then, colonies farther east "no bigger than a dollar" on the breast of a on the Great Britain coast were already ex- bird is enough to bring about death by expo- tinct. Pollution from the Torrey Canyon disas- sure, at least in the colder seas. It is easy to ter alone killed five-sixths of the puffins in the see the relative vulnerability of already main French colony on the Sept Isles in stressed birds in arctic areas to a spill, and be- Brittany and reduced the razorbills to a mere cause of the concentration of these birds in 50 birds, one-ninth of previous numbers available open-water areas, possibilities for (Bourne 1970). catastrophic mortalities are evident. There is every reason to beUeve that similar Such disasters already have occurred in reductions in numbers could occur along the north Pacific waters. Dickason (1970) re- tanker route from Valdez to Puget Sound, ported an incident in which diesel oil reaching with localized extirpation of colonies. Even the Alaska coast, probably from the sinking more disastrous, however, would be an inop- of two Japanese freighters some distance off- portune well blowout or other major spill in shore, affected an estimated 90,000 murres. arctic waters. Massed concentrations of birds, J. G. King, Jr. (cited in Bartonek et al. 1971) already stressed by severe weather and food estimated that at least 100,000 birds, mostly shortages, would be extremely vulnerable to alcids and waterfowl, died in the vicinity of this type of situation. Kodiak Island during winter 1970 as a result As pointed out by Nelson-Smith (1972), of oil pollution (probably ballast dumped by peculiarities of bird behavior determine, to tankers entering Cook Inlet). It must not be some extent, the vulnerability of a species to forgotten that chronic pollution in similar oil spills. Auks, murrelets, and puffins (all Al- areas where oil development and transport ac- cidae), loons (Gauia spp.), grebes (Podiceps tivities are taking place probably kills more spp.), and diving ducks may be most sus- birds every year than die after a single cata- ceptible to oiling. Auks and loons, because strophic spill. Total annual losses due to oil in they float low in the water, may more readily the North Sea and North Atlantic, excluding become completely covered by oil. Diving disasters, amount to 150,000 to 450,000 sea- species that become flightless during their birds (Nelson-Smith 1972). molt, such as alcids and waterfowl, or which That oil pollution, both chronic and cata- do not fly because of social bonds between strophic, can dramatically affect populations adults and flightless young (common murre) of marine birds has already been demon- and spend most of their hves on the water, strated elsewhere. Uspenskii (1964) reported would be particularly vulnerable (J. M. Scott, that more than 30,000 wintering oldsquaws comments by Pacific Seabird Group on U.S. perished from oil pollution near Botland Is- Department of the Interior Draft Environ- land in the Baltic and that in later years this mental Statement 74-90). All divers can easily

species had almost disappeared from Swedish surface into oil, and their reaction is to dive Lapland. Jackass penguins (Spheniscus again, which in a large spill could result in sur- demersus), found only in South Africa, have facing into more oil. Phalaropes (Phalaropus suffered losses from pollution caused by oil spp.), which flock to feed in eddies which con- traffic around the Cape of Good Hope centrate drift, may similarly be vulnerable to (Stander and Venter 1968). Their total popula- adverse effects of oil that would also concen- RESOURCE DEVELOPMENT ALONG COASTS 191 trate in these areas. On the other hand, gulls Indirect Effects of Oil Pollution swimming along the surface are likely to take and Petrochemical Developments wing before becoming seriously contaminated. By no means would direct losses attribut- Nelson-Smith (1972) reported that gannets able to contamination by oil be the only threat (Moras bassana), which collected oiled sea- to marine bird populations as a result of weed for building nest mounds, contaminated petrochemical expansions into these waters. themselves and their eggs. Behavioral prob- Some water birds that become contaminated lems associated with oil spills can be more with nonlethal doses of petroleum during the subtle, however, and Darling's (1938) conclu- breeding season are not likely to breed (J. M. sions that the display of adjacent males con- Scott, comments by Pacific Seabird Group on tributes to stimulation of the female during U.S. Department of the Interior Draft Envi- courtship in seabirds breeding in massed colo- ronmental Statement 74-90). Viability of em- nies, is a good example. If Darling was cor- bryos is greatly reduced when the eggshell be- rect, this behavioral characteristic could comes smeared with oil from the contami- further impede the recovery of a population of nated plumage of the female (Hartung 1965). auks, for example, from mortalities resulting Degradation of habitat, particularly to nest- from catastrophic losses to spills. ing areas and food supplies, will certainly occur, and its most pronounced effects will be On the basis of this information it is pos- felt in the Arctic. Gravel removal for con- sible to predict that alcids, which make up the struction of offshore drilling pads, causeways, bulk of the birds inhabiting the coastal areas and onshore production facilities would dis- during winter (Sanger 1972), would be very place nesting birds and, combined with subse- susceptible to oil spills from future tanker quent discharge of drill cuttings, perhaps traffic in these waters. The potential exists, have an adverse impact on bottom food or- therefore, for a tremendous impact (from a ganisms. Nesting habitat loss through de- single inopportune oil spill) upon these species struction or the inability of birds to accept and upon the entire ecosystem. Sea ducks too, disturbance could be substantial, particularly because of their diving behavior, propensity along the Beaufort Sea coasts of Alaska and for flocking, and flightless molt period, would Canada, where offshore barrier islands and be very vulnerable to oil spills. Wintering tundra-covered islands provide protection flocks of oldsquaws and several species of from mammalian predators for nesting by scoters along the coasts of Alaska, British Pacific eiders, Sabine's gulls (Xemia sabini), Columbia, and Washington can be expected to Arctic terns (Sterna paradisaea), black guille- dwindle as North Slope oil begins to be trans- mots (Cepphus grylle), and other species (Arc- ported to Puget Sound ports. tic Institute of North America 1974). Flax-

It is recognized now that seabirds transfer man Island near the mouth of the Canning and recycle nutrients and energy between trophic River is a tundra island supporting a nesting levels and between regions of an ocean (Sowl population of whistling swans (Olor colum- and Bartonek 1974). Although the signifi- bianus), and the only nesting colony of the cance of this role in the marine ecosystem can Alaska snow goose (Chen caerulescens) is on only be surmised at present, conservative es- Howe Island in the Sagavanirktok River timates by Sanger (1972) indicated that birds Delta (Arctic Institute of North America consume from 0.6 to 1.2 milUon tons of food 1974). and return from 0.12 to 0.24 million tons of feces into the subarctic Pacific region an- Although there would probably be little ac- nually. G. A. Sanger's (personal communica- tual nesting habitat loss for cliff-nesting tion) revised estimates of these bird popula- species, human disturbance to colonies during tions indicated that his 1972 estimates should the nesting period, particularly from heli- be doubled. Regardless, it appears that the copter and fixed-wing aircraft flybys, could disastrous effects of such a spill would extend have considerable impact (Sowl and Bartonek beyond the bird populations involved. 1974). The "living waterfall" effect of thou- 192 D. E. MC KNIGHT AND C. E. KNODER

sands of seabirds pouring off a rookery is stored, is a very important component of the truly spectacular, but each such occurrence annual cycle (Delacour 1964). Snow geese, during incubation and brooding periods breeding mainly in arctic Canada, concentrate causes a rain of eggs or young to fall from the in large numbers on staging grounds along cliffs (Sowl and Bartonek 1974). Temporarily the Beaufort Sea coast of eastern Alaska and abandoned chicks and eggs are susceptible to the Yukon. Because gas compressor stations predation by gulls or jaegers. would be required along the proposed arctic Even for species nesting on level ground, gas pipeline route, experimental studies were aircraft overflights close to breeding colonies conducted in September 1972 to determine may cause major losses to young and eggs. the effect of disturbance from sounds gener- Sladen and LeResche (1970) reported that ated by compressors (LGL Limited 1972c). flights by an LH-34 helicopter (at 305 m alti- These studies indicated that compressor noise tude) over an Adelie penguin (Pygoscelis ade- was disruptive to staging geese. liae) colony caused some egg loss. Landing Indirect effects on marine bird resources re- this aircraft 183 m from the colony caused 50 sulting from development activities may ulti- to 80% of the birds to flee territories, result- mately prove to be more detrimental than the ing in egg and chick loss. Disturbance caused aforementioned direct factors. It is conceiv- by visitors walking through or near nesting able that the impact of these industries, areas of the South African gannet {Sula mainly on the benthic and demersal fauna of capensis) on Bird Island, Lamberts Bay, the coastal areas, could greatly lower the South Africa, caused desertion of nesting carrying capacity of this habitat for marine sites (Jarvis and Cram 1971). Studies of dis- birds (Bartonek et al. 1974). Because of the turbance on breeding black brant. Pacific simplified and short arctic food chains and the eiders, glaucous gulls {Larus hyperboreus), lack of alternative food sources in these areas, and arctic terns at Nunaluk Spit and Phillips arctic ecosystems would be particularly vul- Bay, Yukon, in July 1972 indicated that hu- nerable to this type of problem (Burns and man presence was the most critical form of Morrow 1973). disturbance affecting incubating behavior of Ecological or toxic influences on several these species (LGL Limited 1972a). Dis- food species could result in substantial de- turbance by aircraft— especially helicopters- clines in bird populations. In the Arctic, affected the normal incubating behavior of all where temperatures are low, and bacterial and species except Pacific eiders. Nesting success other decompositional activities are conse- of black brant and arctic terns was reduced by quently slow, spilled oil would persist for this disturbance. many years, with concomitant deleterious ef- Disturbance can adversely affect molting fects on the marine organisms of the area birds. The process of molting places heavy (Burns and Morrow 1973). Reduced recruit- energy demands on birds, and particularly on ment of young would no longer balance inevi- waterfowl whose molt results in a flightless table or density-independent population mor- period; few areas provide adequate protection tality (Ashmole 1971). Although indications from predators necessary during this period. are that arctic species are the most vulnerable Prime molting areas are scarce along the arc- to this type of impact, the lack of knowledge tic coast, yet are vital to the welfare of thou- of the feeding niches of most seabirds discour- sands of sea ducks and seabirds. Studies con- ages further evaluation of this potential prob- ducted by LGL Limited (19726) indicated that lem. It is obvious, however, that ecology of aircraft traffic over sea duck molting areas arctic birds is least understood, and these altered normal behavior, and therefore had a species are the most vulnerable to the detri- detrimental effect. Recommendations result- mental effects of man-caused environmental ing from these studies were that air traffic be degradation. suspended over these areas during the molting season. Conclusions For some arctic-nesting waterfowl, premi- gration staging activity, during which fat re- Predictability of the impact of resource deserves to sustain southward migration are velopment on marine birds in northern waters RESOURCE DEVELOPMENT ALONG COASTS 193

is limited by our relative ignorance of these during exploitation of arctic petroleum re- birds and their ecology. Just as there exists a serves, the potential for disastrous and per- latitudinal gradient in the ecological stability haps irrecoverable losses to northern marine of the ecosystems involved, available knowl- bird species and populations is great. Losses edge of these ecosystems is in inverse rela- of major magnitude could appreciably alter tionship to the latitude at which they occur. the productivity of northern marine ecosys- Arctic bird associations and their fragile envi- tems, to the detriment of other renewable ronments are least understood but are doubt- resources. less the most vulnerable to the detrimental ef- Knowledge of northern marine birds, their fects of man-caused environmental degrada- environments, and their ecology must be tion. Existing technology and support system greatly expanded if the consequences of petro- capabilities of the oil industry are poorly de- chemical exploitation are to be predicted and fined for Arctic areas, further compounding safeguards established against potential this problem (Arctic Institute of North problems. To the extent possible, oil explora- America 1974). tion and development activities should be Although activities associated with the ex- limited to temperate, more stable, marine eco- traction of hard minerals and the timber in- systems, at least until more northerly areas dustry will ultimately affect northern seabirds, are better understood. Similarly, these activi- petrochemical developments pose the most ties must be conducted in such places and at immediate threat to this resource. Explora- such times that impact on the environment tion and development of many coastal and off- will be minimized. State and federal govern- shore sedimentary basins with a potential for ments and the petroleum industry are ulti- oil or gas production are proceeding rapidly. mately answerable for this responsibility. Within a few years, oil storage and loading The Nation must be aware of the potential facilities at Valdez, Alaska, and supertankers costs of energy independence set forth as a plying northern waters will probably result in goal of proposed oil and gas leasing of widespread chronic and localized catastrophic Alaska's outer continental shelf. We must ask contamination of northern marine environ- ourselves if we are willing to risk extermina- ments. Experience in other areas has demon- tion of species to reach this goal, or if we can strated that oil spills are a considerable poten- afford the luxury of reducing the biological tial threat to these bird populations, directly productivity of these waters. through widespread mortality and indirectly through effects on the environment. This threat is of such magnitude that entire popu- References lations or species could be lost to a single spill if it occurred at the wrong place at the wrong Arctic Institute of North America. 1974. The Alas- time of year. Because many of these species kan arctic coast— a background study of available knowledge. 551 require 3 to 4 years for maturation and may pp. Ashmole, N. P. 1971. Seabird ecology and the rear only one or two young per year, recovery marine environment. Pages 223-286 in D. S. time for their populations is great (Ashmole Farner and J. R. King, eds. Avian biology. Vol. I. 1971). For these and other reasons, the Coun- Academic Press, New York. cil on Environmental Quality (1974) con- Bailey, E. P., and G. H. Davenport. 1972. Die-off of cluded that the Gulf of Alaska appeared more common murres on the Alaska Peninsula and vulnerable to major environmental damage Unimak Island. Condor 74(2):215-219. from outer continental shelf oil and gas de- Barry, T. W. 1968. Observations on natural mor- velopment than sites off the Atlantic coast. tality and native use of eider ducks along the Beaufort Sea coast. Can. Field-Nat. 82(2): 140-144. As Bartonek et al. (1971) pointed out, it Bartels, F. B. 1973. Bird survey techniques on would be a national tragedy if the great non- Alaska's north coast. M.S. Thesis. Iowa State game bird populations along Alaska's coast Univ., Ames. 47 pp. were decimated during the "Environmental Bartonek, J. C, J. G. King, and H. K. Nelson. 1971. Decade" without even being properly de- Problems confronting migratory birds in Alaska. scribed. Regardless of information amassed in Trans. N. Am. Wildl. Nat. Resour. Conf. 36:345- the future and precautionary measures taken 361. 194 D. E. MC KNIGHT AND C. E. KNODER

Bartonek, J. C, R. Eisner, and F. H. Fay. 1974. LGL Limited. 1972a. Disturbance studies of breed- Mammals and birds. Pages 23-28 in E. J. Kelley ing black brant, common eiders, glaucous gulls and D. W. Hood, eds. Probes: a prospectus on and Arctic terns at Nunaluk Spit and Phillips Bay, Yukon Territory. Report prepared for processes and resources of the Bering Sea shelf, Northern Engineering Service, Ltd. 50 pp. 1975-1985. Univ. Alaska, Inst. Mar. Sci. Publ. LGL Limited. 19726. Aircraft disturbance to molt- Inf. Bull. 74-1. ing sea ducks, Herschel Island, Yukon Territory. Bourne, W. R. P. 1970. Special review after the Report prepared for Northern Engineering Ser- 112:120-125. "Torrey Canyon" disaster. Ibis vice, Ltd. 31 pp. Burns, J. J., and J. E. Morrow. 1973. The Alaskan LGL Limited. 1972c. Gas compressor noise simu- Arctic marine mammals and fisheries. Arctic oil lator disturbance to snow geese, Kamakuk and gas problems and possibilities, 5th Interna- Beach, Yukon Territory. Report prepared for Northern Engineering Service, Ltd. tional Congress. 24 pp. McKnight, D. E., and B. L. Hiliker. 1970. The im- Campbell, W. J., and S. Martin. 1973. Oil and ice in pact of oil development on waterfowl populations the Arctic Ocean: possible large-scale interac- in Alaska. Proc. Western Assoc. State Game Fish tions. Science 181:56-58. Comm. 50:286-297. Council on Environmental QuaUty. 1974. OCS oil Nelson-Smith, A. 1972. Oil pollution and marine Vol. I. and gas—an environmental assessment. ecology. Paul Elek, Ltd., London. 260 pp. Washington, D.C. 214 pp. Sanger, G. A. 1972. Preliminary standing stock and Darling, F. F. 1938. Bird flocks and the breeding biomass estimates of seabirds on the subarctic cycle; a contribution to the study of avian soci- Pacific region. Pages 589-611 in A. Y. Takenouti abiUty. Cambridge Univ. Press, N.Y. et al., eds. Biological oceanography of the North Pacific. Idemitsu Shoten, Tokyo. Delacour, J. 1964. The waterfowl of the world. Vol. Savile, D. B. O. 1972. Evidence of tree nesting by IV. Country Life Ltd., London. 364 pp. the marbled murrelet in the Queen Charlotte Is- Dickason, O. E. 1970. Center for short-lived phe- lands. Can. Field-Nat. 86(4):389-390. nomena event report. Institution, Smithsonian Sladen, W. J. L., and R. E. LeResche. 1970. New Cambridge, Massachusetts, 36(1970):926. and developing techniques in antarctic ornithol- Dunbar, M. J. 1968. Ecological development in ogy. Pages 585-616 in M. W. Holdgate, ed. Ant- polar regions. A study in evolution. Prentice- arctic Ecology. Vol. I. Academic Press. Hall, Inc., Englewood Cliffs, N.J. 119 pp. Sowl, L. W., and J. C. Bartonek. 1974. Seabirds— Alaska's most neglected resource. Trans. N. Am. Glaeser, J. L., and G. P. Vance. 1971. A study of the Wildl. Nat. Resour. Conf. 39:117-126. behavior of oil spills in the Arctic. U.S. Coast Stander, G. H., and J. A. V. Venter. 1968. Oil pollu- Guard, Office of Research and Development, tion in South Africa. Pages 251-259 in Proceed- Washington, D.C. 60 pp. ings of the International Conference on Oil Pollu- Hansen, H. A. 1962. Canada geese of coastal tion of the Sea. Alaska. Trans. N. Am. Wildl. Nat. Resour. Conf. Swartz, L. G. 1966. Sea-cliff birds. Pages 611-678 in 27:301-320. N. J. WiUmovsky and J. N. Wolfe, eds. Environ- Hansen, H. A., and U. C. Nelson. 1957. Brant of the ment of the Cape Thompson region, Alaska. Bering Sea—migration and mortality. Trans. N. U.S.A.E.C, Div. Tech. Inf., Oak Ridge, Ten- Am. Wildl. Nat. Resour. Conf. 22:237-256. nessee. Thompson, D. and R. A. Person. 1963. The eider Harris, R. D. 1971. Further evidence of tree nesting Q., pass at Point Barrow, Alaska. J. Wildl. Manage. in the marbled murrelet. Can. Field-Nat. 85(1):67- 27(31:348-356. 68. Uspenskii, S. M. 1964. Present day problems of na- Hartung, R. 1965. Some effects of oiling on repro- ture conservation in the Arctic. Problems of the duction of ducks. J. Wildl. Manage. 29(4):872-874. North 7:171-178. Isleib, M. E., and B. Kessel. 1973. Birds of the north Watson, G. E., and G. J. Divoky. 1972. Pelagic bird gulf coast— Prince WilUam Sound region, Alaska. and mammal observations in the eastern Chukchi Biol. Pap. Univ. Alaska 14. 149 pp. Sea, early faU 1970. Pages 111-172 in C. I. Merton Jarvis, M. J. F., and D. L. Cram. 1971. Bird Island, et al., eds. An ecological survey in the eastern Lamberts Bay, South Africa: an attempt at con- Chukchi Sea. U.S. Coast Guard Oceanogr. Rep. servation. Biol. Conserv. 3(4):269-272. 50. Kinney, P. J., D. K. Button, D. M. ScheU, B. R. Williamson, F. S. L., M. C. Thompson, and J. Q. Robertson, and J. Groves. 1970. Quantitative as- Hines. 1966. Pages 437-480 in N. J. WiUmovsky sessment of oil pollution problems in Alaska's and J. N. Wolfe, eds. Environment of the Cape Cook Inlet. Univ. Alaska Inst. Mar. Sci. Rep. Thompson region, Alaska. U.S.A.E.C, Div. Tech. R-69-16. 43 pp. Inf., Oak Ridge, Tennessee. Mortality to Marine Birds Through Commercial Fishing

Warren B.King

International Council for Bird Preservation Smithsonian Institution, Washington, D. C. R. G. B. Brown

Canadian Wildlife Service Dartmouth, Nova Scotia, Canada and Gerald A. Sanger'

U. S. National Marine Fisheries Service Seattle, Washington

Abstract

Commercial fishing has been responsible for incidental mortality of seabirds for centuries, but with the advent of offshore salmon gill-net fishing in the North

Pacific in 1952 and in the North Atlantic in 1965, the magnitude of this kill has increased, and there is strong indication that populations of some seabirds are being adversely affected. Murres (Uria spp.) are most frequently killed, although several other species are caught in lesser numbers. The seabird resources of several nations are involved in this mortality. Longline fishing and inshore gill- net fishing for salmon and cod also are responsible for mortality of seabirds, although usually not in significant numbers.

That the activities of commercial fishermen kittiwakes {Rissa tridactyla), were used for have caused mortality of marine birds sur- food until rather recently (Templeman 1945). prises no one nowadays. Traditions of exploi- This practice has now lapsed, however. tation of marine birds by fishermen date from previous centuries, and fishing has contributed to the extinction of some species. For example, great auks {Pinguinus impennis) and Inshore Fisheries other birds were used as food by fishermen

fishing for Atlantic cod (Gadus morhua) on Until the advent of the offshore salmon gill- the Grand Banks of Newfoundland since the net fisheries in the North Pacific in 1952 and beginning of that fishery in the early 16th cen- the North Atlantic in 1965, most seabird mor- tury (Collins 1884; Lucas 1890). The last great tality in these areas was the result of local auk died in 1844, but smaller species, such as fishing close to shore. Several records of such storm-petrels (Hydrobatidae), greater shear- bird mortality have been published. For waters (Puffinus gravis), and black-legged example, 8,000-10,000 seabirds—presumably mostly alcids—were reported caught annually off Hammerfest in northern Norway (Holger- (personal 'Present address: U.S. Fish and Wildlife Service, sen 1961). E. Brun communication) Office of Biological Services— Coastal Ecosys- reported that the longline fishery off the coast tems, 1011 E. Tudor Road, Anchorage, Alaska of Norway is having serious consequences on 99503. Norwegian populations of murres.

195 196 W. B. KING, R. G. B. BROWN, AND G. A. SANGER

Numbers of alcids are caught in nets set for (D. A. Snarski, personal communication), but Atlantic salmon (Salmo salar) around the this mortahty has not been quantified. coasts of Ireland and Scotland (Biddy 1971). Bilateral agreements between the United A similar situation exists along the west States and Japan, the U.S.S.R. and the Re- Greenland coast, although it is overshadowed public of Korea, concerning the use of inshore there by the direct exploitation of huge num- waters adjacent to some of the Aleutian Is- bers of alcids by hunting. Nonetheless, in lands, Kodiak, Nunivak, St. Matthew, St. 1967 for example, 15,000 alcids were re- George, Kayak, and Forrester Islands permit covered from fish nets in southwestern Green- trawling, longlining, and loading fish and fuel land, where they were sold as food (Evans and in some of these areas and at certain periods. Waterston 1976). The annual salmon catch of Although these activities may affect the sea- the west Greenland inshore fishery has fluc- birds of these areas, the extent of the effects tuated between 60 and 1,500 metric tons and are not known (U.S. Department of the Inte- has averaged about 1,000 tons. There are no rior, Alaska Planning Group 1974). Murie data comparing the relative catch of birds and (1959) indicated, however, that the disappear- fish in this fishery. ance of the ancient murrelet {Synthliboram- Atlantic cod follow the spawning capeUn phus antiquus) from Sanak Island, Gulf of (Mallotus villosus) inshore along the east Alaska, was probably due as much to fisheries coast of Newfoundland in late June and early as to the blue fox industry. It has been sug- July. They are traditionally fished with traps gested that the Japanese murrelet (Synthli- and handlines along this coast, but there has boramphus wumizusumi) may have declined been a recent trend toward using drift nets set as the result of fishing activities near breed- on the bottom. Since alcids feed extensively ing sites off the coast of Japan (Bourne 1971). on capelin at this time, many are caught in the cod nets set in areas close to the large colonies Atlantic Offshore off Witless Bay (D. N. Nettleship, personal Gill-net Fishery communication). Additionally, gill nets are set at the surface for salmon in the same area. In 1965, Denmark began an offshore gill-net Common murres (Uria aalge) are most af- fishery for Atlantic salmon in the Davis fected, but Atlantic puffins {Fratercula arc- Strait off the coast of west Greenland. The tica) are also taken. offshore fishery catch increased from 36 There are as yet no estimates of the total al- metric tons in 1965 to more than 1,200 metric cid mortality from this fishery, although the tons in 1969, and then gradually decreased. annual catch of birds is believed to be smaller The fact that large numbers of seabirds— al- during the present than during the last most entirely thick-billed murres (Uria lom- decade because the fishing effort is reduced, uia)—yfere being drowned in the salmon gill and fishermen in the area now avoid setting nets was brought to the attention of the Inter- nets near alcid concentrations because of the national Council for Bird Preservation at its annoyance of having to remove the birds from 15th World Conference in 1970. The Council's their nets. The Witless Bay colonies contain recommendation was submitted to the Danish over 77,000 pairs of common murres, or 11% government and stated: "... having noted of the total eastern North American popula- that during the 1969 fishing season about tion, and over 235,000 pairs of Atlantic 250,000 individuals of Brunnich's guillemot puffins, or 71% of the North American popu- or thick-billed murre {Uria lomvia) a pelagic lation outside of Greenland (Brown et al. diving bird, were caught in these drift nets 1975). The potential danger is obvious. and drowned, which number represents no There are few data on mortality of seabirds less than 25 percent of the Greenland popula- from inshore commercial fisheries in the tion and exceeds its annual reproductive North Pacific. Some mortality of alcids has capacity; urges the Danish Government, and been shown to take place in Cook Inlet, the national governments of all other coun- Alaska, from beach-netting for Pacific salmon tries involved in this fishing, to take all pos- (Oncorhynchus spp.) adjacent to seabird sible measures to ehminate this very serious rookeries and from drift-netting in the inlet problem." MORTALITY TO MARINE BIRDS THROUGH COMMERCIAL FISHING 197

The figures in the recommendation were not catch by the three Japanese salmon drift-net supported by research; they appeared instead fisheries was about one hundred times that in to have been derived from the observed mor- west Greenland in recent years. The first, the tality on an offshore fishery vessel in 1965, mothership fishery, comprising about 369 which was then related to the salmon catch on catcher-boats^ serviced by 11 motherships, that vessel and applied to the total catch of operates west of 175 °W and generally north the inshore fishery in 1964 (Anonymous of 46 °N during the summer. The second, the 1969). Studies in 1969 and 1970 by the land-based fishery of about 325 ocean-going Fisheries Research Board of Canada finally vessels, operates west of 175°W and south of gave a firm basis for the earlier, though 46 °N; and the third, the coastal fishery, made poorly substantiated concern. On the basis of up of about 1,380 short-haul vessels, operates the assumption that the ratio of salmon to off Hokkaido. The relative salmon catches of murres caught in experimental fishing applied these three fisheries is on the order of to the commercial fishery, an estimate of an 1:1.34:0.65. annual mortality of 0.5 million murres Data collected on U.S. National Marine (±50%) was made on the basis of a salmon Fisheries Service research vessels in 1974 (ob- catch of 1,200 metric tons (TuU et al. 1972). tained through the cooperation of Francis M. The birds being killed were from colonies in Fukuhara and Richard Bakkala, Northwest west Greenland, the eastern Canadian Arctic, Fisheries Center, Seattle, Washington) give, and possibly east Greenland and Spitzbergen. for the first time, an estimate of the magni- Coupled with other known causes of mortality tude of the incidental seabird kill of the Japa- (particularly hunting on the Greenland and nese salmon gill-net fishery. The kill data are Newfoundland coasts, an unknown but defi- available only from the mothership area and nitely substantial kill from oil pollution, a cal- from an area east of it to 165 °W. The Japa- culated mortality of prefledging young, and nese salmon fishery is restricted to waters an unknown natural postfledging mortality) west of 175 °W by agreement with the United there is no doubt that the estimated annual States. Bird kills from the other two areas production of 1.5 million chicks from west may be estimated by the relative salmon Greenland and the Canadian Arctic was less catch figures for the areas, assuming that sea- than the estimated total annual mortality bird densities, species composition, and catch

(Tull et al. 1972). Thus, it comes as no surprise effort are similar. that recent surveys of murre populations of An estimate of the total kill of seabirds in west Greenland and the Canadian Arctic have the mothership area may be made by calculat- revealed massive declines in numbers (Evans ing the bird mortality per length of gill-net set and Waterston 1976; D. N. Nettleship, per- by research vessels, multipHed by the total sonal communication). It is therefore encour- length of gill nets set by the 369 catcher-boats aging news that, as a result of an agreement of the Japanese mothership fishery. About between the United States and Denmark, the 4,666 km of nets are set and retrieved daily offshore salmon gill-net fishery was termi- during the approximately 65-day fishing sea- nated at the end of the 1975 season. The in- son. The estimated annual mortality in the shore fishery remained in operation, however, mothership area is about 75,000 to 250,000 but was restricted to a total annual salmon birds. The lowemumber is based on data from catch of 1,100 metric tons. 10 cruises (450 km of nets set) west of 175 °W, within the area of the mothership fishery. The higher number is based on data from 20 Pacific Offshore Salmon cruises, including those in the first figure, Gill-net Fishery west of 165 °W, and covering the period 18 April to 3 September 1974 (956 km of nets In the north Pacific Ocean, the Japanese gill-net fisheries for salmon (Oncorhynchus ^This figure is based on data through 1971. Since spp.), which have operated since 1952, might then, the number of catcher-boats has decreased be expected to have an even more destructive to 332 in 1974 (F. M. Fukuhara, personal com- effect on seabirds, since the annual salmon munication). 198 W. B. KING, R. G. B. BROWN, AND G. A. SANGER

set), whereas the mothership fishery usually cate whether alcid populations (which make operates between mid-May and late July. As- up two-thirds of the kill) are stable or decreas- suming similar seabird densities and catch per ing. The shearwaters, primarily sooty (Puffi- unit of effort in the areas of the land-based nus griseus) and slender-billed (P. tenuiros- and coastal fisheries, the estimated annual tris), appear to be able to sustain not only mortality is between 214,500 and 715,000 these losses but also a sizable harvest of birds birds. Since 1952, as many as 4.7 million birds of the year (the so-called muttonbirds) on may have been killed by the Japanese salmon their New Zealand and AustraUan breeding gill-net fishery. It must be stressed that sea- grounds. Thus, although the latest estimates bird densities and catch per unit of effort are of the total standing stock of seabirds in the not known to be similar for the areas in ques- North Pacific in summer may be as high as tion; consequently the projection of bird kill 100 million (Sanger and King, this volume), figures from one area to all three is and thus only about 1 of every 200 birds in the speculative. North Pacific region may be caught, the fact In the mothership area and adjacent seas to that a few species, particularly murres, are se- the east, in addition to murres (48% of birds lectively caught raises questions about the killed), significant numbers of shearwaters, impact of this fishery on populations of these Puffinus spp. (27%); puffins (9%); and ful- species. mars, Fulmarus glacialis (5%) are killed, as The U.S.-Japan Migratory Bird Convention are lesser numbers of small alcids, albatrosses of 1973 specifically protects all of the species {Diomedea spp.), and storm-petrels. The thought to be subject to gill- net mortality in murres and puffins taken in the mothership the Pacific. Thus, the Japanese salmon fleet area are of U.S. and U.S.S.R. origin, and the apparently operates in constant violation of shearwaters come from New Zealand, Aus- this convention. tralia, and Chile. In the coastal fishery area, Japanese and U.S.S.R. alcids are taken. Available knowledge of the populations of the Mortality of Albatrosses species making up the bulk of the kill, which has been taking place for 20 years, is insufficient to suggest whether their annual repro- A recent analysis of recoveries of Laysan duction can tolerate such losses. Prohibition albatrosses (Diomedea immutabilis) and of fishing within 160 km of North Pacific sea- black-footed albatrosses (D. nigripes) banded bird breeding islands would help to decrease on the northwest Hawaiian chain from 1937 losses of alcids of U.S. origin, but would not to 1969 showed that of a sample of 532 re- help the shearwaters from the southern covered birds, 57.4% of the Laysan species hemisphere. and 49.5% of the black-footed species were Comparison of statistics of the salmon caught on fishhooks or in nets, and the means fisheries and associated bird kills from the of recovery of many additional birds was North Atlantic and the North Pacific shows thought to have been the same (Robbins and that the North Atlantic salmon fishery is con- Rice 1974). It is likely that the large majority centrated in a relatively small area which is are taken on Japanese and U.S.S.R. longUne also along a major migration pathway of tuna fishing gear. Although this cause of mor- murres. Virtually all seabird mortality is con- tality is insignificant in terms of the total fined to one species. Enough information is at population of either species (only 0.2% of hand to indicate that this cause of mortahty, banded Laysan and 0.8% of banded black- in conjunction with others known to be sig- footed albatrosses have been recovered by nificant, is causing a drastic decline in the any means away from their breeding thick-billed murre population. grounds), these species are protected by the In the North Pacific, on the other hand, the U.S.-Japan Migratory Bird Convention. fishery is more widely dispersed and the ratio Furthermore, the possibility exists that indi- of seabirds to salmon caught is much lower. viduals of the endangered short-tailed alba- Furthermore, several species are subject to tross (Diomedea albatrus) might be killed in mortality. No information is available to indi- this manner. MORTALITY TO MARINE BIRDS THROUGH COMMERCIAL FISHING 199

Long-term Effects of Belopol'skii, L. O. 1961. Ecology of sea colony birds of the Barents Sea. (Transl. from Russian.) Israel Developing Capelin Fishery in Program for Scientific Translations, Jerusalem. Northwest Atlantic 346 pp. Biddy, C. J. 1971. Auks drowned by fishnets. Sea- bird Rep. No. 2. Capelin are important food fish for many Bourne, W. R. P. 1971. General threats to seabirds. seabirds in the northwest Atlantic, and the ICBP [Int. Counc. Bird Preservation] Bull. development and expansion of this fishery off 11:200-219. Brown, R. G. B., D. N. Nettleship, P. Germain, C. E. eastern Canada must be carefully monitored. TuU, and T. Davis. 1975. Atlas of eastern Cana- fishery to In theory, the capelin ought not dian seabirds. Canadian Wildlife Service, Ottawa. seriously affect the birds because it is de- 220 pp. signed to exploit a surplus of capelin artifi- Collins, J. W. 1884. Notes on the habits and meth- of capture of various cially created by the overfishing of Atlantic ods species of seabirds that occur on the fishing banks off the east coast of cod, the capelin 's most important predator. It North America and which are used as bait for is hoped that there is no prospect of the over- catching codfish by New England fishermen. U.S. fishing that may have contributed to the re- Comm. Fish Fish. Rep. 1882:311-335. cent drastic decline of the Peruvian anchovy Evans, P., and G. Waterston. 1976. The decline of the thick-billed murre in Greenland. Polar Rec. (Engraulis ringens) and the seabird species de- 18:283-286. pendent on it (Paulik rela- 1971). However, the Holgersen, H. 1961. On the movements of Nor- tive influence of overfishing and "El Nino" wegian Uria aalge. (In Norwegian, English sum- oceanographic conditions on the decline re- mary.) Sterna 4:229-240. Lucas, F. A. 1890. Expedition to the Island, mains unclear. North Atlantic seabirds are, in Funk with observations on the history and anatomy of any case, more versatile in their feeding the Great Auk. Rep. U.S. Natl. Mus., 1887- habits (Belopol'skii 1961). But, the threat 1888:493-529. may be a subtle one. The important point to Murie, O. J. 1959. Fauna of the Aleutian Islands the seabirds may well be not merely the sur- and Alaska Peninsula. U.S. Fish Wildl. Serv., N. Am. Fauna 61. 406 vival of a reasonably large capeUn stock, but pp. Paulik, A. J. 1971. Anchovies, birds, and fishermen the presence of capelin schools in densi- high in the Peru Current. Pages 156-185 in W. W. Mur- ties in certain areas or at certain seasons. doch, ed. Environmental Resources and Society. Lower densities might, for example, reduce Sinauer Associates, Inc., Stamford, Conn. Recoveries of the foraging efficiency of breeding birds, and Robbins, C. S., and D. W. Rice. 1974. banded Laysan albatrosses (Diomedea immuta- hence their nesting success. The very large bilis) and black-footed albatrosses [D. nigripes). common murre colony on Funk Island, New- Pages 232-271 in W. B. King, ed. Pelagic studies foundland (500,000 pairs: Tuck 1960), might of seabirds in the Central and Eastern Pacific be particularly vulnerable. It lies close to an Ocean. Smithson. Contrib. Zool. 158. Templeman, W. 1945. Observations on some New- area where capelin are especially abundant foundland seabirds. Can. Field-Nat. 59:136-147. and one which is already being exploited by Tuck, L. M. 1960. The murres. Canadian Wildlife the developing fishery. Service, Ottawa. 260 pp. TuU, C. E., P. Germain, and A. W. May. 1972. Mor- tality of thick-billed murres in the west Green- land salmon fishery. Nature (Lond.) 237 (5349):42- 44. References U.S. Department of the Interior, Alaska Planning Group. 1974. Final environmental impact state- Anonymous. 1969. Seabird slaughter. Sports Fish. ment, proposed Alaska Coastal National Wildlife Inst. Bull. 203:5. Refuges. 678 pp.

Interactions Among Marine Birds and Commercial Fish in the Eastern Bering Sea

Richard R. Straty and Richard E. Haight National Marine Fisheries Service Auke Bay Fisheries Laboratory Auke Bay, Alaska 99821

Abstract

The high primary and secondary productivity of the eastern Bering Sea makes it one of the greatest producers of commercial fish and largest congregating areas of marine birds in the world. The fish and birds are so interrelated that fluctuations in the abundance of one may well be responsible for changes in the abundance of the other. The seasonal and annual variation in the impact of birds on fish is a function of the life history, food habits, growth rate, and final size of the fish species of concern and of the distribution, abundance, and feeding habits of bird populations— plus the effects of the environment on these factors. Stages in the life history of some of the important commercial fish and shellfish of the Bering Sea directly or indirectly influenced by marine birds are identified.

The eastern Bering Sea is one of the world's waters inhabited by Ammodytidae and Clu- richest fish-producing areas and is also one of peidae in the North Sea (Pearson 1968). the world's major congregating areas for The eastern Bering Sea contains members marine birds. The large extent of the conti- of these and other fish famiUes that are exten- nental shelf and the climatic and oceano- sively exploited by man; the fish are also im- graphic characteristics of the eastern Bering portant as forage for other species of commer- Sea combine to make this region extremely cial fish, marine mammals, and marine birds. productive biologically. The distribution and During some part of their Ufe cycles, all fish abundance of plankton, benthos, and fish de- species feed on plankton, nekton, benthos, or termine the distribution, time, and character other fishes. of the migration of marine birds in the eastern The incidental use or dependence of marine Bering Sea (Shuntov 1961). Several studies birds on commercial fish and the items on have illustrated the close relation between which the fish feed account for the major in- marine birds and the biological properties of teraction between man and these two groups surface waters (Tuck 1960; Bourne 1963; Solo- of animals. mensen 1965). Spatial and temporal varia- In this paper, we consider how marine birds tions in the abundance of the fish families Clu- and fish interact. Although some of what we peidae (herring), Gadidae (codfish), Osmeridae present is only speculative, we identify cer- (capelin), and Ammodytidae (sand lance) are tain areas that have received Uttle or no scien- thought to be major determinants of the tific study, areas in which further research is breeding seasons, breeding places, and move- needed for a better understanding of the role ments of boreal seabirds (Ashmole 1971). The of commercial fish in the ecology and dy- timing of breeding among larids and alcids is namics of marine birds in the eastern Bering related to the seasonal changes in the surface Sea.

201 202 R. R. STRATY AND R. E. HAIGHT

Commercial Fish Resources size of fish in the commercial catch (H. of the Eastern Bering Sea Larkins, personal communication). The notable exception is the king crab (Paralithodes sp.), which has increased in Most of the fishing in the eastern Bering abundance in recent years as a result of reduced foreign fish- Sea is done by Japan and the Soviet Union. ing. Japan resumed fishing in the Bering Sea in 1953 (7 years after World War II), the Soviet Union started fishing in the region in 1959, and since the early 1960's both nations have accelerated their exploitation of Bering Sea fish stocks (Chitwood 1969). Species of major concern to Japan and the Soviet Union include fish—walleye pollock (Theragra chalcogramma), yellowfin sole (Limanda aspera). Pacific cod (Gadus macrocephalus). Pacific ocean perch (Sebastes alutus). Pacific herring (Clupea harengus pallasi), and sablefish (Anoplopoma fimbria)— and snow crabs (Chionoecetes spp.). The dis- Fig. 1. Areas of major of tribution of the principal species being har- concentrations ground fish (Pacific pollock, halibut, yellowfin sole, rock sole, vested in Bristol Bay and the eastern Bering flathead sole. Pacific ocean perch, and Pacific Sea are shown in Figs. 1, 2, and 3. The weight cod) in Bristol Bay and the Bering Sea. of each of the major species in the total catches made by foreign and domestic fishermen in 1973 is shown in Table 1. In 1972, the catch of commercial finfish in the eastern Bering Sea alone amounted to 5% of the total world catch of marine fishes (H. Larkins, personal communication). Most species of commercial fish in the Bering Sea are in a state of decline or in a depressed condition from overexploitation

(Table 1). This is indicated by a reduction in the catch per unit of effort and in the mean

Table 1. Foreign and domestic catch of fish Fig. 2. Areas of major winter and spring concentra- and shellfish in the eastern Bering Sea, in- tions of Pacific herring in Bristol Bay and the cluding Bristol Bay, 1973. Bering Sea.

Catch Species (metric tons)

Fish Pollock 1,500,000 Flatfish 125,000 Pacific cod 45,000 Herring 35,033 Salmon 11,785 Sablefish 7,000 Pacific halibut 222 Other 40,000 Shellfish King crabs 26,798 Snow crabs 17,694 Fig. 3. Areas of major concentrations of king and Shrimp Minor snow crab in Bristol Bay and the Bering Sea. INTERACTIONS AMONG MARINE BIRDS AND COMMERCIAL FISH 203

Routes of Interaction Between Marine Birds and Commercial Fish

The obvious ways in which marine birds and fish of commercial importance interact in the eastern Bering Sea are illustrated by the simplified food web diagram in Fig. 4. The major animal groups and species included in two of the categories in this figure— secondary producers (invertebrate forage) and intermediate Fig. 4. Food web in the eastern Bering Sea, showing routes of interaction between marine birds and carnivores (commercial and forage marine fish the various life history stages of commercial fish and shellfish)— are as follows: and shellfish.

Secondary producers Intermediate carnivores

Zooplankton and micronekton Eggs (Uttoral, adhesive) Copepods Clupeidae Calanus spp. Eucalanus spp. Pelagic larvae Gadidae Euphausiids Pleuronectidae Thysanoessa spp. Osmeridae Ammodytidae Amphipods Salmonidae Parathemisto spp, Gadidae Gammarus spp. Pandalidae Pteropods Spiratella spp. Juvenile and small adults Clione spp. Clupeidae Osmeridae Chaetognaths Ammodytidae Sagitta spp. Salmonidae Benthos Gadidae Polychaetes Pandalidae Nereis spp. Euroe spp. Large adults Clupeidae Molluscs Gadidae Mytilus edulis Pleuronectidae Tonicella spp. Salmonidae Fusitriton oregonensis Scorpaenidae Echinodermata Lithodidae Strongylocentrotus spp. Majiidae Pandalidae Crustacea Gammaridae Mysidae Marine birds Idothea spp. Alcidae Pagurus spp. Procellarildae Hapalogaster spp. Laridae Sclerocrangon spp. Phalacrocoracidae 204 R. R. STRATY AND R. E. HAIGHT

In our discussion, we mainly consider pre- comiculata), and the ancient murrelet {Synth- dation by birds on commercial fish and com- liboramphus antiquus); and the larids, mainly petition between birds and commercial fish the glaucous-winged gull (Larus glaucescens) for food. The extent of these interactions de- and the black-legg6d kittiwake (Rissa termines the potential for birds and fish to in- tridactyla). fluence each other's abundance. The extent of In winter, the alcids and larids appear to be the interactions also determines the impact of the most abundant groups, the procellariids man's commercial harvest of fish on the abun- having been reduced by the departure of the dance of birds or of the bird's harvest on the slender-billed shearwaters for breeding abundance of fish. grounds in the southern hemisphere. The se- The extent of the interaction between lection of the types of food to be consumed by marine birds and commercial fish depends on these marine birds is a function of their mor- the abundance, distribution, feeding habits, phological and physiological adaptations and and life history of the fish species of concern. of the resultant feeding behavior. Ashmole We have limited our discussion to examples of (1971) classified the feeding behavior of the major commercial pelagic and demersal various genera of marine birds and the rela- fish and shellfish of the eastern Bering Sea. tive importance of the kinds of food eaten by We also use as examples those species of each group; this information for some of the marine birds whose abundance in the eastern Bering Sea bird species occurring in the Bering Sea and feeding habits give them the genera listed by Ashmole (1971) is sum- greatest potential for influence on, or being in- marized in Fig. 5. fluenced by, fish abundance. Fish and invertebrates are evidently of moderate to major importance in the diet of

these marine birds (Fig. 5). The extent to Abundance and Feeding Habits which a given fish species is fed upon by or is in competition with marine birds for food is of Marine Birds in the determined by the life history of the fish. Eastern Bering Sea Most pelagic and some demersal fish and shellfish are more subject to predation by pur- Information on the general abundance and suit diving birds than by birds restricted to distribution of the most important marine the near-surface waters. Invertebrates appear birds in the eastern Bering Sea in the summer to be equal to or more important than fish in and winter is scattered among many pub- the diets of birds feeding in near-surface lished and unpubhshed reports: Shuntov waters (Fig. 5). (1961, 1966), Sanger (1972), Bartonek and Gibson (1972), and Ogi and Tsujita (1973); and surveys by D. T. Montgomery and W, E. Oien Predation by Marine Birds ("Bristol Bay waterbird survey, 1972," unpublished report of the U.S. Bureau of Sport The literature contains numerous accounts Fisheries and Wildlife, Alaska area) and by of marine birds feeding on marine fish and J. G. King and D. E. McKnight (1969, "A shellfish of commercial importance. Some waterbird survey in Bristol Bay and pro- studies quantify the impact of some bird posals for future studies," unpublished report species on certain species of commercial fish of the U.S. Bureau of Sport Fisheries and (Outram 1958; Shaefer 1970; Wiens and Scott Wildlife and the Alaska Department of Fish 1976) and shellfish (Glude 1967). Other and Game, Juneau, Alaska). studies have shown that in some regions the In summer, the most abundant birds appear value of guano produced by birds may exceed to be the procellariids, mainly the slender- the value of the commercial fish they consume billed shearwater (Puffinus tenuirostris) and (Jarvis 1970). Some fish of worldwide com- Pacific fulmar (Fulmarus glacialis); the al- mercial importance that are important in the cids, mainly the common murre {Uria aalge), diets of marine birds are listed in Table 2. thick-billed murre {U. lomvia), tufted puffin The significance of bird predation on pelagic (Lunda cirrhata), horned puffin {Fratercula or demersal fish and shellfish (Fig. 5) depends INTERACTIONS AMONG MARINE BIRDS AND COMMERCIAL FISH 205

Table 2. Fish of worldwide commercial importance in the diets of some marine birds.

Fish Shearwaters Mun Puffins Fulmars GuUs Anchovy X — Sardines X — Herring X X X Sprat X — Pilchard X — CapeHn — X X Salmon — X Mackerel — X Pollock — X Haddock — X Cod — X

on the feeding behavior of the birds and on the torn as adults have pelagic stages during hfe history of the fish (e.g., distribution, abun- which they are vulnerable to predation by dance, growth, and adult size). Pursuit diving marine birds. Juveniles of some demersal birds, such as murres and puffins, can con- species (pollock, cod, halibut, some species of sume fish at greater depths than can birds sole, and king crabs) are sometimes found in that feed near the surface, such as shear- shallow water where they might be subject to waters, kittiwakes, fulmars, and gulls. predation by birds.

FEEDING BEHAVIOR FOOD TYPE 1 Demersal Fish and Shellfish

z i z > si i ti The early life histories of the commercially CROUP z < z 5 2 < > ^ 5 I i 1 5 ii < important demersal fish of the eastern Bering SHEARWATERS • • • • • • • Sea are quite different (Table 3). For example, FULMARS • • • • • • • • the eggs larvae of Pacific halibut {Hippo- MURRES and PUFFINS i • glossus stenolepis) generally occur at depths MURRELET • • • CULLS • • • • • • • • • • • greater than 100 m (Hart 1973), whereas KITTtWAKES • • • • • • • • • • those of pollock and yellowfin sole are found # OF MINOR IMPORTANCE at or near the surface (Musienko 1963, 1970). OF MODERATE IMPORTANCE A OF MAJOR IMPORTANCE The eggs of Pacific cod are demersal, but the larvae are oceanic (pelagic) and occur from 25- Fig. 5. Feeding behavior and relative importance of 150 m (Mukhacheva and Zviagina 1960). food of some groups of marine birds that occur in In their juvenile stages, demersal fish the eastern Bering Sea. many frequent the near-surface waters (Table 3), where they become vulnerable to predation by piscivorous marine birds. Juvenile pollock, for Aspects of the Life example, form into small schools that usually Histories of Fish Related to move about close to the bottom but some- Predation by Marine Birds times move into areas as shallow as 3 m. Juvenile Pacific cod prefer the warmer water Fish that are pelagic during part of their close to shore and may be found within 10 m lives, such as salmon and herring, and forage of the surface (Moiseev 1953). The young of fish like smelt, capelin, and sand lance, are many species of flatfish, such as yellowfin vulnerable to greater predation by a wider sole, rock sole (Lepidopsetta bilineata), and variety of marine birds that are bottom-dwell- flathead sole (Hippoglosoides elassodon), re- ing demersal fish, such as pollock, cod, sole, main for a time in shallow warm water after ocean perch, and halibut, as well as king and assuming a demersal existence. Yellowfin sole snow crabs. Some species that live on the bot- 2-2.5 cm in total length may be found in abun- 1 <

206 R. R. STRATY AND R. E. HAIGHT

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INTERACTIONS AMONG MARINE BIRDS AND COMMERCIAL FISH 207

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~~INTERACTIONS AMONG MARINE BIRDS AND COMMERCIAL FISH 209~~

dance in areas as shallow as 5 m (Fadeev 1965; marily on the location of their spawning Moiseev 1953). grounds, their growth rates, and the size of The commercially important king and snow the adults. The spawning location determines crabs of the eastern Bering Sea also have lar- the extent of predation on eggs, whereas val stages that are pelagic (Table 3). Zoeae growth rate and adult size determine during and megalopa of snow crabs are found near how much of its lifetime a given fish species is the surface where they are vulnerable to vulnerable to the wide variety of marine birds. plankton-feeding marine birds. The eggs of Herring spawn in intertidal and subtidal king crabs are attached to the abdomen of the zones and spend most of their postlarval lives female, but after hatching, the larvae become in bays or estuaries near the coast. They de- pelagic and occur near the surface. They are posit their adhesive eggs primarily on vegeta- planktonic through five larval stages before tion, and the eggs are particularly vulnerable settling to the bottom to take up demersal to predation by a wide variety of marine and residence (Kurata 1960, 1964). These larvae terrestrial birds. Outram (1958) estimated attain a length of 5.5-6.5 mm and spend 33 that gulls alone accounted for 39% of the egg days or more in the plankton (Kurata 1960). loss on the spawning grounds at Vancouver Even after the young king crabs have settled Island, British Columbia. When herring lar- to the bottom, they may still frequent water vae hatch, they are between 0.7 and 0.8 cm shallow enough to make them vulnerable to long; when they metamorphose about 6-8 predation by some marine birds. Juvenile king weeks later, they are between 2.6 and 3.5 cm crabs 1 and 2 years of age appear to prefer long. Thereafter, juvenile herring grow shallower water than do older crabs. In south- rapidly and reach a length of about 7-10 cm eastern Alaska, during the spring, small juve- before winter. Although herring as old as 13 nile crabs have been observed in pods at years and up to 38 cm long have been reported depths as little as 1 m below the low tide level. in Alaska, they seldom exceed 30 cm and 1 The available life stages of king and snow years of age (Rounsefell 1929). During spring crabs and commercially important demersal and summer, herring are commonly within fish (Table 3) represent an enormous food 10 m of the surface, but in winter, they are in supply for other fishes and marine birds. Pre- water 100-140 m deep. Although herring are dation by marine birds on pelagic eggs and on particularly vulnerable to predation in spring the larval and juvenile stages of demersal fish and summer, they are available to marine is not well documented, probably because the birds during most of their life. rapid digestion rate of birds makes species The life history of capelin is somewhat dif- identification of these stages difficult. Inves- ferent than that of herring—they live in the tigators must often depend on the presence of open sea near the surface and throughout the the hard parts of fish (such as scales and oto- water column most of their lives. Sometime in liths) in the stomachs of birds to identify the June or early July, they migrate in large species eaten. Because these hard parts have schools toward shore to spawn (Musienko not yet formed in the larvae and most juve- 1970). In British Columbia, capelin bury their niles, predation by marine birds on older fish eggs in coarse sand and gravel in the inter- is more apparent on examination of stomach tidal and subtidal zones. The larvae are 0.5- contents. Full understanding of predation by 0.7 cm long at hatching and are carried by marine birds on demersal fish and shellfish re- currents to the open sea where they develop in quires additional data on when and where the the plankton. Capelin attain an age of 5 years egg, larval, and juvenile stages are present. and a maximum length of about 22 cm; their small size makes them vulnerable to preda- Pelagic Fish tion by marine birds most of their lives, and they are an important pelagic food fish for Many fish, such as herring, capelin, smelt, other commercial fish in the Bering Sea. and salmon, are pelagic for part of their lives, The sand lance reaches a maximum size of particularly during the spring and summer 20-26 cm and is vulnerable to bird predation feeding periods. The extent of predation by during most of its life. Little information is marine birds on these species depends pri- available on the maximum age attained by 210 R. R. STRATY AND R. E. HAIGHT

this species in the Bering Sea, but because of its size, it is an important forage fish for many commercial fish species. The five species of Pacific salmon of the eastern Bering Sea spawn in fresh water, unlike herring, capelin, and sand lance. Their eggs are not vulnerable to extensive predation by marine birds; gulls take mainly salmon eggs which have been dislodged from the gravel and are drifting or being rolled along the stream bottom by the current (Moyle 1966). After a few months to several years in fresh water, the juvenile salmon (5-14 cm long) enter the Bering Sea during late spring Fig. 6. Distribution of juvenile sockeye salmon in or early summer and migrate through these Bristol Bay and the eastern Bering Sea (adapted waters to feeding grounds, primarily in the from Straty 1974). north Pacific Ocean. At maturity, the survivors return to their home streams and rivers to spawn. It is during the seaward mi- rather discrete coastal migration routes gratory phase of their life cycle that salmon through the Bering Sea (Fig. 6), with the re- are most vulnerable to predation by marine sult that predators have access to an abun- birds. dant but transient food supply. The sockeye salmon [Oncorhynchus nerka) The only published account of predation by is the most abundant and valuable species marine birds on juvenile salmon in the Bering harvested by American fishermen in the Sea is that of Ogi and Tsujita (1973). They waters adjacent to the Bering Sea and, as a re- found juvenile sockeye salmon in the sult, the one that has been most extensively stomachs of murres captured in gill nets in studied during early marine life. Juvenile the eastern Bering Sea. The predation did not sockeye salmon are between 8 and 14 cm long appear extensive, but most of the birds were when they enter the Bering Sea between late captured outside or on the fringes of the main May and early July. They are most abundant seaward migration route of the salmon. The in the upper 1 m of water at night and the foods of marine birds should be studied in con- upper 2 m during the day (Straty 1974)— well junction with studies of the migrations of within the regime that can be exploited by juvenile salmon. many species of marine birds. The numbers of juvenile sockeye salmon mi- Influence of Growth Rate grating seaward from the Bristol Bay region of the Bering Sea in a single year has ranged and Adult Size of Fish on between 46.3 and 370.4 million (H. Jaenicke, the Extent of Predation personal communication). This is equivalent to between 409 and 3,267 metric tons (on the Incubation time for fish eggs, the length of basis of the mean weight of the juveniles when the pelagic larval period (Table 3), and the they enter the Bering Sea). These large num- growth rate of juvenile fish are species- bers of juvenile sockeye salmon, plus juvenile specific and temperature-dependent. The ex- Chinook salmon (O. tshawytscha), coho sal- tent to which a fish species is subjected to pre- mon (O. kisutch), chum salmon (O. keta), and dation by marine birds is directly related to pink salmon (O. gorbuscha) from all other the rate at which development and growth rivers entering the Bering Sea, represent a occur. For example, the less time it takes the considerable input of energy from fresh water pelagic eggs of demersal fish and shellfish to in the form of prime forage fish for other hatch and complete pelagic larval life, the less fishes, marine birds, and mammals. Young is the time they will be preyed on by marine salmon enter the Bering Sea each year over a birds. For fish species that are pelagic during period of only 6 to 8 weeks and may follow their entire life, the rate of growth will deter- INTERACTIONS AMONG MARINE BIRDS AND COMMERCIAL FISH 211

mine how long they remain small enough for vestigators have even alluded to competition birds to eat. Some of the smaller pelagic fish, between marine birds and fish for food. Ogi such as herring, capelin, and smelt, are vulner- and Tsujita (1973) mentioned that competi- able to bird predation most of their lives; tion seemed to exist between murres and juve- larger pelagic species like salmon may be nile sockeye salmon for euphausiids in the preyed on for only a very short time. The eastern Bering Sea. We have listed some of maximum size fish that can be eaten by the types of forage fish and invertebrates marine birds is, therefore, important in eaten by commercial fish (Table 4) and marine evaluating predation on a given species of birds (Table 5) in the eastern Bering Sea; com- fish. parison of these two tables clearly indicates The literature on the food habits of marine that competition could occur. birds contains little on the sizes of fish con- The principal factors determining the ex- sumed. Tuck (1960) stated that murres prob- tent of competition between marine birds and ably will take fish up to 18 cm long. Ogi and fish are the numbers of birds and fish, the Tsujita (1973) estimated the lengths of Pacific length of time that various life history stages pollock in the stomachs of murres taken in the of the fish are in association with the birds, eastern Bering Sea at 24 cm. and the abundance of the preferred foods at Herring in the eastern Bering Sea reach an these times. The impact of competition de- age of 1 1 years and grow to about 33 cm. pends on the adaptability of the birds and fish Herring could, therefore, be taken during to alternative types of food. most of their lives by murres but during only The types and sizes of food eaten by fish the first few years by smaller birds such as vary with the life history stage—especially fulmars and shearwaters. Capelin and some with size at each stage. For instance, very species of smelt would be vulnerable to birds young herring eat the eggs and nauplii of during all their lives. Although the size of copepods or small copepodite stages and bar- adult Pacific salmon varies with the species, nacles. As herring grow, their diet includes they are all so large that they are not preyed small fish and larger zooplankton, such as upon by marine birds. Once in the ocean, juve- mature copepods, amphipods, euphausiids, nile salmon grow at such a rapid rate that and pteropods. Pacific cod shorter than 9 cm they are probably not very vulnerable to feed on small crustaceans (Moiseev 1953), marine birds after their first 4 to 6 months at whereas larger cod eat young crabs, shrimp, sea. Limited studies on the growth of juvenile and fish. Small juvenile sockeye salmon feed sockeye salmon in the eastern Bering Sea mainly on larval stages of euphausiids (Straty (Straty 1974) indicate they may double their 1974), but larger juveniles also eat the more size in their first 8 weeks at sea. A sockeye sal- adult forms, which eventually make up a sig- mon that entered the Bering Sea at 12 cm in nificant part of their diet (Nishiyama 1974). mid-June would be 24 cm long in August—the The change in the diet of fishes with growth maximum size that a murre could eat; the fish results in competition with a changing variety could be eaten by smaller marine birds for of marine birds. For example, deep-diving much less time. Pink and chum salmon enter birds may replace surface feeders as the major the sea at a smaller size than sockeye salmon bird competitors of the Pacific cod and pol- and would be vulnerable to predation both by lock as these fish increase in size and seek a greater variety of marine birds and for a deeper waters. The diet of cod changes from longer period of time. small crustaceans in shallow water to progressively larger food that eventually includes herring, lance, shrimp, and crabs. The Competition Between sand change to herring and sand lance, and quite Commercial Fish and possibly small crabs, places the adult cod in Marine Birds competition with both the surface feeders and pursuit diving birds, but adult cod do not We do not know the importance of competi- compete with birds for zooplankton. tion between marine birds and commercial As pollock increase in size, they continue to fish in the eastern Bering Sea. Only a few in- feed mainly on zooplankton, but they change 212 R. R. STRATY AND R. E. HAIGHT

~~Table 4. Food items eaten by the adult stage of seven commercially important species offish in the eastern Bering Sea.~~

~~Pacific Food Walleye Pacific ocean Yellowfin Pacific item Herring Salmon pollock cod perch sole halibut~~

Invertebrates Pteropods X X — — X — — Squid — X — X X — X Polychaetes X X X X — X X Copepods X X X — — — — Amphipods X X X X X X — Euphausiids X X X — X X — Decapods X X X X X X X Fish CapeUn X X X X — X — Sand lance - X X X — — X

~~Table 5. Forage fish and invertebrate foods eaten by seven species of marine birds in the eastern Bering Sea.~~

~~Food item Shearwaters Murres Puffins Murrelets Fulmars Kittiwakes Gulls~~

Forage fish Sand lance X X X X Capelin — — X Invertebrates Copepods — — — Euphausiids X X — Amphipods X X — Decapods X X — Pteropods — X — Chaetognaths — — — Polychaetes — X X X Squid X X — X

from copepods near the surface to euphausiids in Bristol Bay and the eastern Bering Sea. at mid-depths and near the bottom. Euphau- The diets of many species of birds and fish, siids are large and abundant zooplankters however, seem to be largely determined by which, for the most part, are available only to their physiological and morphological adapta- deep-diving birds. Adult pollock also consume tions and resultant feeding behavior. For in- herring, sand lance, capelin, and other small stance, adult sockeye and pink salmon have fish. well-developed gill rakers and feed largely on Both marine birds and fish are capable of zooplankton, whereas chinook and coho sal- exploiting a wide variety of food, and often mon have poorly developed gill rakers and their stomach contents reflect the relative feed almost entirely on fish. In the eastern abundance of food items in the area. Ogi and Bering Sea, murres appear to prefer the Tsujita (1973) illustrated the differences in Pacific sand lance, whereas the slender-billed the food taken by murres captured at dif- shearwater consumes mainly euphausiids (Ogi ferent locations in the eastern Bering Sea. and Tsujita 1973). Thus, murres may be Carlson (1977) and Ogi and Tsujita (1973) re- greater competitors with piscivorous fish ported on differences in the diet of juvenile than are shearwaters. Shearwaters are prob- sockeye salmon captured at various locations ably more important as competitors with zoo- INTERACTIONS AMONG MARINE BIRDS AND COMMERCIAL FISH 213

plankton-eating fish that inhabit shallow that kittiwakes are most abundant along the water in juvenile stages and with pelagic fish edge of the continental shelf in the Bering Sea species (such as pollock, herring, salmon, and in the summertime. This distribution coin- capelin) that are heavily dependent on cides with the distribution of the eggs and lar- euphausiids. vae of pollock, certain flatfish, rockfish, sable- Some species of marine birds may interact fish, and several other species. These birds with fish as predators and competitors. As an both exploit the fish directly (predation) and example, pursuit diving birds, such as murres compete with them for plankton. Not enough and puffins, may be important predators on information is available on the food habits of juvenile salmon in the eastern Bering Sea, but birds at the time fish eggs and larvae are these same birds may compete for food with present to evaluate this interaction. adult salmon. Surface-feeding birds, such as fulmars, shearwaters, kittiwakes, and gulls, may be important as both predators and com- Environmental Influence on petitors with herring and capeUn and some Predation and Competition demersal fish. Between Marine Birds and Commercial Fish

Dependency of Marine Birds Because fish are cold-blooded animals, tem- on Commercial Fish perature, through its influence on the rate of metaboUsm, is a major variable in determin- The interactions of commercial fish and ing the amount of energy needed for mainte- marine birds of the Bering Sea can be deter- nance and for performing such essential ac-

mined only if we know their distribution, tivities as swimming and feeding— fish are abundance, and food habits, especially while less active, feed less, and grow more slowly in they are associated with one another. Infor- cold waters. For example, growth in young mation is particularly lacking for all life his- sockeye salmon is very slow at temperatures tory stages of commercial fish species and the lower than 4°C (Donaldson and Foster 1941), seasonal movements of birds. We have some and temperature profoundly affects their knowledge of the distribution and abundance swimming speed (Brett et al. 1958). The rates of the various Ufe history stages and the food of development of the eggs of some flatfish habits of commercial fish in the Bering Sea. are closely correlated with water temperature Little is known of the abundance, seasonal (Ketchen 1956)— flatfish developed more movements, and food habits of marine birds rapidly at higher temperatures (Fig. 8). At in this region, however, probably because lower temperatures, the rate of growth is also marine birds have had little direct commercial slower and, therefore, the duration of pelagic value in the northern hemisphere. Food larval life is longer for demersal fish and shell- studies on marine birds are particularly diffi- fish. cult because their rapid digestion soon de- Variations in sea temperature should, there- stroys the identity of the food. fore, influence the extent to which fish are vul- We can make a reasonable guess as to some nerable to predation and competition. For bird-fish associations for two regions of the example, eggs would take a longer time to Bering Sea where we have information on the hatch in colder than in warmer sea water. In distribution of marine birds and the various both pelagic fish such as herring, whose eggs life history stages of commercial fish. For are laid in the intertidal zone, and in demersal example, piscivorous birds, such as murres, fish with pelagic eggs such as the sole, the puffins, black-legged kittiwakes, and slender- period of vulnerability of eggs to bird preda- billed shearwaters, are extremely abundant in tion would be extended. At lower tempera- the summer along the seaward migration tures the length of the pelagic life of demersal

route of juvenile sockeye salmon (Fig. 7); the fish and shellfish and their vulnerability to juvenile salmon, kittiwakes, and shearwaters predation would also be greater than at higher all feed on plankton. Shuntov (1961) showed temperatures. For example, the number of 214 R. R. STRATY AND R. E. HAIGHT

~~TUFTED PUFFIN V r~~

~~-> t~~

~~• J ... ,.4 K^~~

~~0* /.T .-~~

~~A SLENDER-BILLED SHEAR-,./ WATER~~

~~LEGEND: Number of birds per 32.18-km segment: 1-5 • 6-100 • 101-1.000 •1,001 + Sighting from land: °~~

~~Fig. 7. Distribution and numbers of birds observed in Bristol Bay along seaward migration route of sockeye salmon (from Bartonek and Gibson 1972).~~

days between molts of the zoeal stages of are of a size that could be eaten by would-be snow crabs is temperature-dependent—the predators would increase; (2) lower sea tem- warmer the water, the less the time between peratures would reduce the feeding by fish molts (Kon 1970). and decrease the competition by fish for food

Temperature, through its effects on swim- exploited by birds; and (3) higher sea tempera- ming speed, feeding activity, and growth of tures would have the opposite effect—the juvenile fish, might influence the magnitude feeding by fish would increase consumption of of predation by birds on pelagic fish in the fol- the foods that birds feed on.

~~lowing ways: (1) lower sea temperatures In the eastern Bering Sea, water tempera- would increase the vulnerabiUty of juvenile tures may vary greatly between years for the~~

fish to bird predation because swimming same month (Fig. 9). Such variation should re- speed would decrease, and the time the fish sult in variation in the temperature-de- INTERACTIONS AMONG MARINE BIRDS AND COMMERCIAL FISH 215

I I I I —r-r I ' ' ' ' tified. I I A reduction in stocks of a fish species could result in a reduced supply of food for a species of bird and cause a shift in the diet of 25 this bird to other species of fish or to more zooplankton. For a bird species with specific food preferences, this could mean a reduction

I 20 in its abundance to a level supportable by the available food supply. For bird species with less specific food requirements, a reduction in O species fish -J 15 a of could mean a reduction in competition for food with that fish—which could increase survival of the birds. Man's intentional harvest of marine birds, 10 such as the shearwater in parts of the southern hemisphere, and his inadvertent harvest — of other bird species which are entangled or 5 caught in fishing gear reduce predation and competition by marine birds. This, in turn, may aid the survival of the fish stocks in the

Ql I I I I I I 1 I _l l_J I I 1—1 L_l_ Bering Sea. -5 5 10 15 The status of most stocks of commercial TEMPERATURE CC.) fish and shellfish in the Bering Sea is such that reductions in harvest are warranted, Fig. 8. The relation of temperature to the rate of de- have been proposed, or are in effect. If the velopment to hatching of lemon sole, as compared 200-mile (61-km) limit of jurisdiction over the with two European flatfishes (Ketchen 1956). marine resources by adjacent coastal States is implemented, either as a result of the Law of the Sea Conferences or unilaterally by the pendent activities of fish and, in turn, in mag- United States, we can expect commercial fish- nitude of marine bird predation and coming in the eastern Bering Sea to be more petition. tightly regulated. Such action should result in a reduction in harvest of those fish species now in a depleted condition, which, in turn, Possible Influences of Man could influence the abundance of marine on the Interaction of Marine birds. Now is an opportune time to implement Birds with Commercial Fish the studies required to increase our knowledge of the abundance, distribution, and sea- We have noted that the abundance and age sonal movements of marine birds and their and size composition of major stocks of fish in relationship to commercial fish resources of the Bering Sea have been drastically reduced the eastern Bering Sea. by commercial fishing. This has resulted in the reduction in numbers of fish at all hfe history stages, including those on which marine Conclusions birds and other fishes depend for food. What effect this reduction has had on the abun- • The eastern Bering Sea is a region of high dance and distribution of marine birds in the biological productivity; it is one of the world's Bering Sea is unknown. It depends in part on great producers of commercial fish and major the ability of birds to eat other fish or increase congregating areas for marine birds. their use of zooplankton or nekton. • The vulnerability of fish to predation by We can hypothesize on probable changes in marine birds depends on life history features, bird and fish abundance that resulted from such as place of spawning, duration of larval the heavy commercial harvest of fish but any stages, growth rate, sea temperature, and such changes cannot be documented or quan- adult size of fish, and on the distribution. 216 R. R. STRATY AND R. E. HAIGHT

~~DEPTH IM METERS JUNE 10-20.1971 (TEMP. C"AT 10 METERS) i_ I5S»~~

~~Fig. 9. Sea temperatures in Bristol Bay and southeastern Bering Sea in mid-June and early July of 1967 and 1971 (from Straty 1974). INTERACTIONS AMONG MARINE BIRDS AND COMMERCIAL FISH 217~~

feeding behavior, and food habits of marine action could result in changes in the abun- birds. dance of the marine birds of this region by • The most apparent predation by marine creating an increased food supply for some birds on fish is on fish large or mature enough and decreased supply for others. that some hard body parts persist and can be found in the stomach samples of birds.

• Little is known of the extent of bird preda- Acknowledgments tion on the pelagic eggs and larvae of We thank J. C. Bartonek and H. R. Carlson, demersal fish and shellfish in the Bering Sea H. Jaenicke, H. Larkins, and B. L. for because of lack of investigation and the rapid Wing supplying various materials presented in this digestion of eggs and larvae by birds. paper. • Predation by marine birds on juvenile salmon is not well documented because of the lack of investigation in areas where both birds and fish are present. References • Marine birds and commercial fish eat similar zooplankton and fish in the eastern Bering Ahlstrom, E. H. 1959. Vertical distribution of Sea. The food exploited by both generally re- pelagic fish eggs and larvae off California and Baja California. U.S. Fish Wildl. Serv. Fish. flects the relative abundance of the types of Bull. 60(161):107-146. food in the area, but food preference is dis- Ahlstrom, E. H. 1961. Distribution and relative played by some species of fish and birds. abundance of rockfish (Sebastodes spp.) larvae of • More is known about the food habits of the California and Baja California. Int. Comm. commercial fish than of the marine birds of Northwest. Atl. Fish. Spec. Publ. 3:169-176. Ashmole, N. P. 1971. Sea bird ecology and the the Bering Sea. marine environment. Pages 223-286 in D. S. • Sea water temperature may be a major en- Farner, J. R. King, and K. C. Parkes, eds. Avian vironmental factor in the Bering Sea since it Biology. Vol. 1. Academic Press, New York. influences both the extent to which fish are Bartonek, J. C, and D. D. Gibson. 1972. Summer distribution of pelagic birds in Bristol Bay, vulnerable to predation and the amount of Alaska. Condor 74(4):416-422. competition with marine birds. Sea tempera- Bourne, W. R. P. 1963. A review of oceanic studies tures may vary greatly from year to year in of the biology of seabirds. Proc. Int. Ornithol. the Bering Sea, and this may result in varia- Congr. 13:831-854. tions in the magnitude of predation and com- Brett, J. R., M. Hollands, and D. F. Alderdice. 1958. The effect ot temperature on the cruising speed of petition between birds and fish. young sockeye and coho salmon. J. Fish. Res. • The distribution of marine birds and the Board Can. 15(4):587-605. various stages in the life history of commer- Carlson, H. R. 1977. Food habits of juvenile sock- cial fish are not well known for the eastern eye salmon, Oncorhynchus nerka, in the inshore coastal waters of Bristol Bay, Alaska. Fish. Bull. Bering Sea. Where these have been studied, 74(2):458-462. they are intimately related. Such knowledge is Chitwood, P. E. 1969. Japanese, Soviet, and South required to gain some insight into even the Korean Fisheries off Alaska, development and potential for predation and competition in the history through 1966. U.S. Fish Wildl. Serv. Circ. dynamics of the marine bird and commercial 310. 34 pp. Clemens, W. A., and G. V. Wilby. 1961. Fishes of fish populations of this region. In two in- the Pacific Coast of Canada. Fish. Res. Board stances, it is that the of known occurrence Can., Bull. 68, 2d ed. 443 pp. marine birds and the early life history stages Donaldson, L. R., and F. J. Foster. 1941. Experi- of fish coincide so as to result in both poten- mental study of the effect of various water temperatures on the growth, food utilization, and tial predation on the fish by the birds and mortality rates of fingerling sockeye salmon. competition for food between the fish and the Trans. Am. Fish. Soc. 70:339-346. birds. Fadeev, N. S. 1965. Comparative outline of the biol- • The possibility exists that the commercial ogy of flatfishes in the southeastern part of the fish resources of the eastern Bering Sea will Bering Sea and the condition of their resources. Part pages 112-119 in Soviet fisheries investi- eventually come under the jurisdiction of the 4, gations in the northeast Pacific Ocean. (Trans, United States. This could mean reduced har- from Russian.) Israel Program for Scientific vests of fish to restore depleted stocks. Such Translations, Jerusalem. 218 R. R. STRATY AND R. E. HAIGHT

Glude, J. B. 1967. The effect of scoter duck preda- Lisovenko, L. A. 1965. Fecundity of Sebastodes tion on a clam population in Dabob Bay, Wash- alutus Gilbert in the Gulf of Alaska. Part 4, pages ington. Proc. Natl. Shellfish Assoc. 55:73-86. 162-169 in Soviet fisheries investigations in the Hart, J. L. 1973. Pacific fishes of Canada. Fish. Res. northeast Pacific Ocean. (Transl. from Russian.) Board Can., Bull. 180. 740 pp. Israel Program for Scientific Translations, Haynes, E. 1973. Descriptions of prezoeae and Jerusalem. stage 1 zoeae of Chionoecetes bairdi and C. opilio Lyubimova, T. G. 1965. Main stages in the life cycle (Oxyrhyncha Oregoniinae). U.S. Natl. Mar. Fish. of the rockfish Sebastodes alutus Gilbert in the Serv. Fish. Bull. 73:769-775. Gulf of Alaska. Part 4, pages 85-111 in Soviet Ito, K. 1968. Ecological studies on the edible crab, fisheries investigations in the northeast Pacific Chionoecetes opilio (O. Fabricius) in the Japan Ocean. (Transl. from Russian.) Israel Program for Sea. II. Description of young crabs, with note on Scientific Translations, Jerusalem. their distribution. Bull. Jpn. Sea Reg. Fish. Res. Moiseev, P. A. 1953. Cod and flounders of far-east- Lab. 19:43-50. (Transl. from Japanese.) Fish. Res. ern waters. (Transl. from Russian.) Fish. Res. Board Can. Transl. Ser. 1184. Board Can. Transl. Ser. 119. Jarvis, M. J. F. 1970. Interactions between man Motoh, H. 1973. Laboratory-reared zoeae and and the South African gannet Sula capensis. megalopa of zuwai crab from the Sea of Japan. Ostrich Suppl. 8:497-513. Bull. Jpn. Soc. Sci. Fish. 39(12):1223-1230. Moyle, P. 1966. Feeding behavior of the glaucous- A. A. 1965a. Winter ichthyoplankton of Kashkina, winged gull on an Alaskan salmon stream. Wilson Islands region. Part pages the Commander 4, BuU. 78(2):175-190. 170-181 in Soviet fisheries investigations in the Mukhacheva, V. A., and O. A. Zviagina. 1960. De- northeast Pacific Ocean. (Transl. from Russian.) velopment of the Pacific Ocean cod Gadus Israel Program for Scientific Translations, morhua macrocephalus Tilesius. (Transl. from Jerusalem. Russian.) Fish. Res. Board Can., Transl. Ser. 393. Kashkina, A. A. 19656. Reproduction of yellowfin Musienko, L. N. 1963. Ichthyoplankton of the sole (Limanda aspera Pallas) and changes in its Bering Sea (data of the Bering Sea Expedition of spawning stocks in the eastern Bering Sea. Part 1958-59). Part 1, pages 251-286 in Soviet fisheries pages 182-190 in Soviet fisheries investigations 4, investigations in the northeast Pacific Ocean. in the northeast Pacific Ocean. (Transl. from Rus- (Transl. from Russian.) Israel Program for Scien- sian.) Israel Program for Scientific Translations, tific Translations, Jerusalem. Jerusalem. Musienko, L. N. 1970. Reproduction and develop- Kashkina, A. A. 1970. Summer ichthyoplankton of ment of Bering Sea fishes. Part 5, pages 161-224 the Bering Sea. Part pages 225-247 in Soviet 5, in Soviet fisheries investigations in the northeast fisheries investigations in the northeast Pacific Pacific Ocean. (Transl. from Russian.) Israel Pro- Ocean. (Transl. from Russian.) Israel Program for gram for Scientific Translations, Jerusalem. Scientific Translations, Jerusalem. Nishiyama, T. 1974. Energy requirement of Bristol Ketchen, K. S. 1956. Factors influencing the sur- Bay sockeye salmon in the central Bering Sea and vival of the lemon sole (Parophrys vetulus) in Bristol Bay. Inst. Mar. Sci., Univ. Alaska 2:321- Hecate Strait, British Columbia. J. Fish. Res. 343. Board Can. 13(5):647-694. Novikov, N. P. 1964. Basic elements of the biology Kobayashi, K. 1963. Larvae and young of the whit- of the Pacific halibut (Hippoglossus hippoglossus ing, Theragra chalcogramma (Pallas), from the stenolepis Schmidt) in the Bering Sea. Part 2, north Pacific. Bull. Fac. Fish. Hokkaido Univ. pages 175-219 in Soviet fisheries investigations 14(2):55-63. in the northeast Pacific Ocean. (Transl. from Rus- Kon, T. 1970. Fisheries biology of the tanner crab. sian.) Israel Program for Scientific Translations, IV. The duration of planktonic stages estimated Jerusalem. by rearing experiments of larvae. Bull., Jpn. Soc. Ogi, H., and T. Tsujita. 1973. Preliminary examina- Sci. Fish. 36(3):219-224. (Transl. from Japanese.) tion of stomach contents of murres (Una spp.) Fish. Res. Board Can. Transl. Ser. 1603. from the eastern Bering Sea and Bristol Bay, Korolev, N. G. 1964. The biology and commercial June-August 1970 and 1971. Jpn. J. Ecol. exploitation of the king crab, Paralithodes cam- 23(5):201-209. tschatica (Tilesius), in the southeastern Bering Outram, D. N. 1958. The magnitude of herring Sea. Part pages 102-108 in Soviet fisheries in- 2, spawn losses due to bird predation on the west vestigations in the northeast Pacific Ocean. coast of Vancouver Island. Fish. Res. Board Can., (Transl. from Russian.) Israel Program for Scien- Prog. Rep. Pac. Coast Stn. 111:9-13. tific Translations, Jerusalem. Paraketsov, I. A. 1963. On the biology of Sebas- Kurata, H. 1960. Studies on the larva and post- todes alutus of the Bering Sea. Part 1, pages 319- larva oi Paralithodes camtschatica. III. The influ- 327 in Soviet fisheries investigations in the ence of temperature and salinity on the survival northeast Pacific Ocean. (Transl. from Russian.) and growth of the larva. Bull. Hokkaido Reg. Israel Program for Scientific Translations, Fish. Res. Lab. 21:9-14. Jerusalem. Kurata, H. 1964. Larvae of the decapod Crustacea Pearson, T. H. 1968. The feeding biology of sea-bird of Hokkaido. 6. Lithodidae (Anomwia). Bull. Hok- species breeding on the Fame Islands, North- kaido Reg. Fish. Res. Lab. 28:49-65. umberland. J. Anim. Ecol. 37:521-552. INTERACTIONS AMONG MARINE BIRDS AND COMMERCIAL FISH 219

Pertseva-Ostraumova, T. A. 1954. Material on the Shuntov, V. P. 1961. Migration and distribution of development of the far-eastern flatfish. 1. De- marine birds in the southeastern Bering Sea dur- velopment of the yellowfin sole. Tr. Inst. ing spring-summer season. Zool. Zh. 40(7): 1058- Okeanol. Akad. Nauk., SSSR-11. 1069. (In Russian, summary in Enghsh.) Reid, G. J. 1972. Alaska's fishery resources, the Shuntov, V. P. 1966. Concerning wintering of birds Pacific herring. U.S. Natl. Mar. Fish. Serv., Fish. in the far eastern seas and in the northern part of Facts 2. 20 pp. the Pacific Ocean. Zool. Zh. 45(11):698-711. Rodin, V. E. 1970. An estimation of the state of the (Transl. from Russian.) Can. Wildl. Serv. king crab (Paralithodes camtschatica Tilesius) Solomensen, F. 1965. The geographical variation of stock in the southeastern Bering Sea. Part 5, the fulmar {Fulmarus glacealis) and the zones of pages 149-156 in Soviet fisheries investigations marine environment in the North Atlantic. Auk in the northeast Pacific Ocean. (Transl. from Rus- 82:327-355. sian.) Israel Program for Scientific Translations, Stevenson, J. C. 1962. Distribution and survival of Jerusalem. herring larvae [Clupea pallasi Valenciennes) in Rounsefell, G. A. 1929. Contribution to the biology British Columbia waters. J. Fish. Res. Board of the Pacific herring, Clupea pallasii, and the Can. 19(5):735-810. condition of the fishery in Alaska. Bull. U.S. Bur. Straty, R. R. 1974. Ecology and behavior of juve- Fish. 45:227-320. nile sockeye salmon (Oncorhynchus nerka) in Rumyantsev, A. I., and M. A. Darda. 1970. Summer Bristol Bay and the eastern Bering Sea. Inst. herring in the eastern Bering Sea. Part 5, pages Mar. Sci., Univ. Alaska, Occas. Publ. 2:285-320. 409-441 in Soviet fisheries investigations in the Tanino, Y., H. Tsujisaki, K. Nakamichi, and K. northeastern Pacific Ocean. (Transl. from Rus- Kyushin. 1959. On the maturity of Alaska pol- sian.) Israel Program for Scientific Translations, lock, Theragra chalcogramma (Pallas). Bull. Hok- Jerusalem. kaido Reg. Fish. Res. Lab. 20:145-164. Sanger, G. A. 1972. Preliminary standing stock and Taylor, F. H. C. 1967. The relationship of midwater biomass estimates of seabirds in the subarctic trawl catches to sound scattering layers off the Pacific region. Pages 499-611 in A. Y. Takenouti, coast of northern British Columbia. J. Fish. Res. ed. Biological oceanography of the northern Board Can. 25(3):457-472. north Pacific Ocean. Tuck, L. M. 1960. The murres: their distribution, Serobaba, I.I. 1968. On the spawning of Alaska pol- populations, and biology, a study of the genus lock Theragra chalcogramma (Pallas) in the Una. Can. Wildl. Ser. 1. 260 pp. northeastern part of the Bering Sea. Vopr. Wiens, J. A., and J. M. Scott. 1976. Model estima- Ikhtiol. 6(53):992-1003. (Transl. from Russian.) tion of energy flow in Oregon coastal seabird Israel Program for Scientific Translations, populations. Condor 77(4):439-452. Jerusalem. Yusa, T. 1954. On the normal development of the Shaefer, M. B. 1970. Men, birds, and anchovies in fish, Theragra chalcogramma (Pallas), Alaska pol- the Peru current—dynamic interactions. Trans. lock. Bull. Hokkaido Reg. Fish. Res. Lab. 10. Am. Fish. Soc. 99(3):461-467. 15 pp.

~~Interrelations Between Seabirds and Introduced Animals~~

~~Robert D. Jones, Jr.~~

~~U.S. Fish and Wildlife Service 1011 East Tudor Road Anchorage, Alaska 99507 and G. Vernon Byrd'~~

~~U.S. Fish and Wildlife Service Aleutian Islands National Wildlife Refuge Adak, Alaska~~

~~Abstract~~

Animals introduced to insular seabird habitats are of both intentional and accidental origin. The results of the introductions—particularly of herbivores—cannot be predicted, but may range from severely destructive to beneficial. Herbi- vores are of both domestic and wild stocks of ungulates, hares, and rabbits. Rats are the most commonly introduced omnivore on a worldwide basis. In Alaska the commonest carnivore introduction has been the red fox {Vulpes fulva) and arctic fox (Alopex lagopus), and the first of these were made in the early 19th century by the Russian-American Company. These foxes nearly extirpated the Aleutian Canada goose (Branta canadensis leucopareia) from its nesting grounds. Black flies (Simuliidae), which are vectors of avian blood parasites, have been introduced to three of the Aleutian Islands.

The purpose of this paper is to discuss some immigrants. These systems have achieved influences of introduced animals, primarily ecological homeostasis through reciprocal mammals, on seabirds and their nesting habi- adaptation over an extended period. Experi- tat, with emphasis on the coasts of Washing- ence has shown that introductions to such ton, British Columbia, and Alaska. Our dis- systems result in severe perturbations (Odum cussion focuses on island introductions partly 1971:221). because a large proportion of seabirds choose The introductions can be categorized as island nesting sites, and because islands pre- being either intentional or accidental events. sent ecosystems vulnerable to such in- Effects of such introductions have varied troductions. widely, depending on the type of animal intro- Flightless animals have no means of immi- duced, the types of birds present and the habi- gration, hence little probabiUty of colonizing tat they occupy, the size and shape of the is- islands. In these circumstances marine birds land, the type of nesting area used by the evolve populations in relatively simple ecosys- birds, and the status of their populations be- tems (Carlquist 1965; MacArthur and Wilson fore the introduction. An example drawn from 1967), though the degree of simpUcity de- our Aleutian experience with galhnaceous pends on several variables, including the is- birds illustrates the interaction of these vari- land's size and its distance from a source of ables. The dark phase of the arctic fox {Alopex lagopus) was introduced to Adak and Am- 'Present address: Hawaiian Islands National Wild- chitka islands, both of which had native popu- life Refuge, Kilauea, Hawaii. lations of the rock ptarmigan, Lagopus mutus

~~221 222 R. D. JONES AND G. V. BYRD~~

(Gabrielson and Lincoln 1959). Foxes were re- vegetation and birds. He cited various papers leased on Adak in 1924, and on Amchitka in attributing destruction of colonies of shear- 1921. Adak has an area of 751 km'' and Am- waters {Puffinus sp.) to the activities of sheep, chitka 350 km^ Adak is irregular in shape primarily their treading on the burrows. He with extensive precipitous shorelines, rela- found, however, that on Big Green Island and tively few beaches, and a large, central moun- Phillip Island, sheep were not responsible for tainous hinterland which foxes rarely pene- declines in shearwater breeding success, nor trated. Amchitka, on the other hand, presents did they prevent expansion of colonies. a zone of marine planation on its eastern two Other authors have reported damage to sea- thirds, low mountains on the rest, shelving bird nesting areas by sheep. One such beaches around most of the island, and a long, example in the eastern North Pacific region linear, narrow shape that foxes explored com- concerns Protection Island, Washington. Ac- pletely. By 1949 ptarmigan were difficult to cording to Richardson (1961), 100 to 300 find on Amchitka, and then only in the sheep grazed freely on the island since 1958. section of the mountains. highest, steepest He reported damage by grazing and frequent were extirpated from the low, eastern They trampling of nesting areas of rhinoceros auk- two thirds of the island. The foxes flourished lets (Cerorhinca monocerata). Landslides were on Amchitka, but did much less well on Adak, initiated by these activities, rendering the where the ptarmigan population fluctuated in slopes unusable by auklets. Of the burrows in a normal cyclic manner, apparently uninflu- his study area, 46% were buried by slides. He enced by the foxes. Then the foxes were eradi- did not determine mortality. cated on Amchitka in the 1950's, and by 1962 the ptarmigan had spread over the whole of Other avian consequences may flow from the island and become one of the most con- sheep introductions. Husbandry of these spicuous avian features of the landscape. ungulates has been practiced with varying success for many years in the Aleutian Islands, most notably on Umnak and Un- alaska islands, both of which have large na- Animal Introductions tive populations of bald eagles, Haliaeetus leucocephalus (Gabrielson and Lincoln 1959). Nonpredatory Animals Before the introduction of sheep, these raptors oriented to the hunting fish and Man has taken ungulates with him to many were sea, seabirds. Sheep presented a new resource and islands. Although numerous records of live- presently itself confronted stock introductions are available, few provide the industry found that information relating to the effects of these by a formidable predator, and demanded eagles (letter to Egan, animals on the habitat and their fauna unless be destroyed William of from S. Bynum, the impact has been severe. Governor Alaska, James Secretary-treasurer, Company, Inc.). A most noteworthy example of destruction Umnak by ungulates occurred on Guadalupe Island Other ungulates introduced on Alaska is- off the coast of Baja California. Domestic lands include cattle (Bos taurus) on Chernof- goats {Capra hircus) were introduced in the ski and Chernabura islands; caribou (Rangifer unrecorded past with the result that little of tarandus) on Adak; reindeer on St. Matthew, the once abundant vegetation remains. In its Nunivak, Atka, Umnak, St. Paul, St. place introduced species capable of withstand- Lawrence, Hagemeister, and Kodiak as well ing heavy grazing are abundant over most of as many interior locations; deer (Odocoileus the island. Several endemic avian species are hemionus) on Kodiak and Afognak; elk now considered extinct, including the Guada- (Cervus canadensis) on Afognak; and musk lupe storm-petrel, Oceanodroma macrodac- oxen (Ovibos moschatus) on Nunivak. All tyla (Howell and Cade 1954; Jehl 1972). these animals have maintained populations on Sheep (Ovis aries) have been introduced to islands for a time, and some appear likely to seabird nesting islands with varying results. do so into the distant future. Specific effects In Bass Strait, Australia, Norman (1970) on seabirds is generally not known, but studied the effects of introduced sheep on trampling of grassy slopes such as that re- INTERRELATIONS BETWEEN SEABIRDS AND INTRODUCED ANIMALS 223

ported for sheep develops in some cases. have developed sustaining populations in the Bailey et al. (1933) speculated that nests of presence of large seabird populations without the snow goose (Anser caerulescens) were de- measurable effect on the birds. On Ananiuliak stroyed by reindeer or their herdsmen in the glaucous-winged gulls (Lams glaucescens) Point Barrow area. have been observed feeding on rabbits (W. S. The destruction of vegetation by introduced Laughlin, personal communication). rabbits and hares has been documented for Invertebrates have been introduced on many areas in the world. This destruction has three islands in the Aleutians. The black fly often extended to seabirds. Perhaps the most (Simulium sp.) reached Adak by 1958, dramatic example occurred on Laysan Island Shemya by 1964, and Amchitka in connection in the Hawaiian archipelago, where rabbits of with activities of the Atomic Energy Commis- unknown species were introduced in 1903. Ac- sion in 1968. Apparently the insects were cording to Warner (1963) it took less than 20 transported on jet aircraft. The pest appears years for the rabbits to remove every green well established on Adak, but its status on the plant but three patches of Sesuvium portu- other two islands is uncertain. Like the mos- lacastrum. The Laysan duck {Anas laysanen- quito, the female black fly sucks blood from sis) was brought perilously close to extinc- warm-blooded animals, and in the process be- tion. The rabbits were eliminated in the comes the vector of a Leucocytozoan blood 1920's, and the population of ducks increased parasite of birds. In years of black fly abun- to over 600 by 1963, a figure thought to ap- dance at Seney (Michigan) National Wildlife proximate the predisturbance population. Refuge the blood parasite has been respon- European hares (Lepus europaeiis) were in- sible for reproductive failure in Canada geese troduced on Smith, San Juan, and Long is- {Branta canadensis; Sherwood 1968). If black lands, in Washington. On Smith Island, these fly problems reach such a scale in the Aleu- burrowing animals apparently grazed nearly tians, the parasites might prove limiting to all the succulent vegetation close to the pelagic birds as well as to waterfowl. Winds, ground. By 1924, their burrows riddled the for which the Aleutian region is famous, con- bluffs, causing them to cave into the ocean stitute a limiting factor for obligate blood- (Couch 1929). Couch found no seabirds nest- feeding Simuliids and may control the ing on the island, but found numerous tufted severity of this problem. puffins (Lunda cirrhata) present on the bluffs, but not nesting. A removal campaign was directed against the hares in 1924 and in a few Predatory Animals years they were gone. Smith Island now supports nesting pelagic birds (D. Manuwal, per- The list of introduced animals that prey on sonal communication). seabirds is extensive. Often several animals Accounts of hare and rabbit introductions have been introduced to the same island. For to islands are legion, but not all such introduc- example, in 1951 Amchitka Island in the tions have drastically affected seabirds. Aleutians supported populations of feral dogs Manana Island, Hawaii, is such a case. {Canis familiaris) and cats (Felis catus), rats Tomich et al. (1968) believed that introduced (Rattus norvegicus), and arctic fox. Their rabbits (Oryctolagus cuniculas) were not even presence resulted from three of the usual indirectly detrimental to the nesting noddies sources of predator introductions: escape of (Anous tolidus) and sooty terns (Sterna fus- pets, escape from visiting ships (and aircraft), cata). In some situations, introduced lago- and commercial introductions. Add introduc- morphs have been credited with benefiting tions to control pests, such as that of the mon- seabirds. Lockley (1942) suggested that goose (Herpestes auropunctatus) to the rabbits helped to open new breeding colonies Hawaiian Islands, and only one source re- of manx shearwaters {Puffinus puffinus) at mains—the desire of man to improve on na- Skomer and in west Wales in general. In ture. In the Aleutians this impulse has taken Alaska rabbits were introduced to Middleton the more innocuous form of fish and plant in- Island in 1952 (Rausch 1958) and to Ananiu- troductions, such as rainbow trout {Salmo liak Island at an earlier unrecorded date. Both gairdneri) on Adak and Shemya, and trees 224 R. D. JONES AND G. V. BYRD

(mostly Sitka spruce, Picea sitkensis) on black rats (Rattus rattus) were responsible for every military base in the "Chain." the extremely low nesting success of the Rats appear to be the most commonly intro- petrels there. duced predators on a worldwide scale. Ships In British Columbia, Campbell (1968) re- furnish the traditional source of their intro- corded predation by the Alexandrian rat duction, but one of us (R.D.J.) has observed (R. rattus) on ancient murrelets (Synthli- them disembarking from a military aircraft at boramphus antiquus) at Langara Island. The Cold Bay on the Alaska Peninsula. These ani- extent of damage to the murrelet population mals probably entered the plane at Adak, is not known. which received rats from military ships early The animals most widely introduced in in World War II. Alaska seabird habitat are the red fox (Vulpes Rats may be able to exploit a larger percent- fulva) and the arctic fox. The red fox is native age of the seabird species on a given island to the Alaska Peninsula and to the eastern- than other introduced predators because they most group of islands in the Aleutians, known can enter crevices and burrows in search of as the Lissii or Fox Islands (Berkh 1823; the birds and their eggs and young. They also Murie 1959). At the other end of the archipel- destroy ground-nesters, and cliff-nesters may ago, in the group known as the Near Islands, not be altogether safe from them. Clayton M. Attu Island has a native population of the White (personal communication) found that arctic fox (Tikhmenev 1861; Bancroft 1886). Rattus norvegicus had ravaged every one of Between Umnak Island, the westernmost is- 16 eyries of the peregrine falcon {Falco pere- land of the Fox group, and Attu there are no grinus) that he checked in 1971 at Amchitka native terrestrial mammals, and substantial Island, Alaska. Only one egg had tooth avian populations evolved an ecology in the marks, however. Kenyon (1961) ascribed the absence of mammahan predation (Murie disappearance of the song sparrow {Melospiza 1959). melodia maxima) and the winter wren (Troglo- At the time of Russian contact with the dytes troglodytes kiskensis) from Amchitka Aleutians, both fox species were dominantly to predation by rats. dark phase, and the early introductions Many authors have mentioned potential rat (about 1836) by the Russian-American Com- damage, but few have quantitatively docu- pany were of both species (Tikhmenev 1861). mented it. Imber (1974), however, provided Initially both species were successful in de- data concerning the magnitude of rat preda- veloping insular populations, but in the long tion on diving petrels and storm-petrels on run the arctic fox proved the more successful. some New Zealand islands. He found that rats At Great Sitkin, Adak, and Kanaga, intro- were taking between 10 and 35% of the chicks duced red foxes maintained populations that of gray-faced petrels (Pterodroma macroptera were eliminated in the 1920's to be replaced gouldi) on Whale Island in the parts of the by arctic foxes (unpublished records of the colonies where burrows were dense. On those Aleutian Islands National Wildlife Refuge). parts of the island with a very low density of Differential harvest of the preferred dark petrel burrows, rats were believed to have phase had in the meantime altered the genetic killed virtually every chick. Imber revealed makeup of the population, and the Ught phase that where Polynesian rats (Rattus exulans) had become dominant. In the arctic fox popu- occur, diving petrels and storm-petrels are lations, the dark phase remained generally rare or absent, though they are widespread on dominant at about 95%, but in some small is- neighboring islands. Imber concluded from lands with limited genetic stock (e.g., the his studies of the ecology of petrels and Poly- Semichis) the proportion approached one to nesian and Norway rats that a petrel colony is one (unpublished records of the Aleutian Is- endangered if invaded by a species of rat lands National Wildlife Refuge). whose maximum weight approaches or ex- By 1936, the Aleutian archipelago consti- ceeds the mean adult weight of the petrel. tuted a large-scale fox farm, which in its 23 Harris (1970), who worked with dark-rumped years of existence as a refuge had produced petrels (Pterodroma phacopygia) on Santa 25,641 fox pelts with a value of $1,162,826. Cruz in the Galapagos Islands, indicated that During the same period, and perhaps earlier, INTERRELATIONS BETWEEN SEABIRDS AND INTRODUCED ANIMALS 225

arctic foxes were introduced on almost every the Coast Guard LORAN station are reported island from the Aleutians to Prince William to take common eiders (Somateria Sound, and on some of the islands in south- mollissima). eastern Alaska. The Aleutian Islands Na- tional Wildlife Refuge maintained records Conclusions from which the above figures are quoted, but though records of other islands' use for fur Ecological consequences of animal introduc- farms exist in the archives of the Alaska tions to islands are rarely well documented. Game Commission, no record of the fur values Usually no thought is devoted to such conse- was kept. quences until redress becomes difficult or Murie (1959) assessed the influence of the quite impossible. Many of the introductions foxes by examining 2,501 fox droppings col- stem from a period before ecological under- lected in 1936 and 1937 from 22 of the Aleu- standing, and the introduced animal has ac- tian Islands. He reported 57.8% of the food quired the status of a native. The arctic fox in items in these droppings was avian—48.9% the Aleutians fits all of these conditions. Until seabirds. The result of his investigations was we conducted a thorough search of the litera- the adoption of new policies governing is- ture, some of it difficult to secure and written suance of permits for fox farming in the in several languages, the original status of Refuge. The essential feature of these policies this animal was not known. Its eUmination, was the revocation of certain existing per- now under way on selected islands, is difficult mits, with a view to reserving the islands con- and expensive. Rapid recovery of some avian cerned for wildUfe use. The decision proved species, including certain passerines, has been academic, for fur prices declined until no mar- observed. However, ecological homeostasis is ket for Aleutian arctic fox pelts could be the product of evolution, and restoration in found. But the foxes remained. the Aleutians must follow that course. It is The most obvious damage has been the not likely to proceed rapidly to a point nearly complete extermination of the Aleu- thought desirable by man. The accidental in- tian Canada goose (Branta canadensis leuco- troductions of animals such as rats and black pareia). It has vanished from its former nest- flies in the Aleutians constitute particularly ing range in the Aleutian and Kuril Islands, irksome events because they cannot be re- except for Buldir Island in the western Aleu- versed. The new ecology of Amchitka, from tians (Jones 1963). Clark (1910) described this which the foxes have been removed, must goose as extremely abundant on Agattu Is- evolve in the presence of these species. Its land in 1909; however, foxes from Attu were face will look very different than if they were introduced there in 1923, 1925, and 1929. not there. We would Uke to suggest a means Murie (1959) found "probably less than six by which such introductions may be pre- pairs" in 4 days of traveUng over the island in vented, but it seems hkely that more, not less, 1937. can be expected. In our main area of interest, cats appear to Preventing the introduction of ungulates have been widely introduced, but we found no seems more likely to be successful, especially record of extensive predation on marine birds. if the islands lie within a National Wildlife Jehl (1972) attributed the extinction of the Refuge. Even this, however, becomes less cer- Guadalupe petrel to predation by cats, in com- tain with an expanding human population bination with the destruction of vegetation by and, with it, demands for more land on which goats. Imber (1974) reported that "serious to produce food. predation by cats upon a colony of gray-faced Legal restrictions have been suggested as a petrels on Little Barrier Island, New Zealand means to control or prevent introductions, was observed in 1950. Since that time, the but in the northern islands, little enforcement colony has become extinct." is likely. There is a phrase bearing on this, Though feral dogs are reported present on said to have governed human behavior in the islands in our area of interest, they do not ap- early years of Caucasoid occupation of the pear to have significant influence on seabirds. Aleutian Islands, "Heaven is too high and the On Attu Island, the pet dogs of personnel of Czar too far away." 226 R. D. JONES AND G. V. BYRD

References Jehl, J. R. 1972. On the cold trail of an extinct petrel. Pac. Discovery 25:24-28. Jones, R. D. 1963. Buldir Island, site of a remnant Bailey, A. M., C. D. Brower, and L. B. Bishop. 1933. breeding population of Aleutian Canada geese. Birds of the region of Point Barrow, Alaska. Wildfowl Trust Annu. Rep. 14:80-84. Prog. Act. Chic. Acad. Sci. 4(2): 14-40. Kenyon, K. W. 1961. Birds of Amchitka Island, Bancroft, H. H. 1886. History of Alaska, 1730-1885. Alaska. Auk 78(3):305-326. San Francisco. Lockley, R. M. 1942. Shearwaters. Devin-Adair, Berkh, V. 1823. The chronological history of the dis- New York. covery of the Aleutian Islands or the exploits of MacArthur, R. H., and E. O. Wilson. 1967. The the Russian merchants. N. Grech., St. Peters- theory of island biogeography. Princeton Univ. burg. Press, Princeton, N.J. Campbell, R. W. 1968. Alexandrian rat predation on Murie, O. J. 1959. Fauna of the Aleutian Islands ancient murrelet eggs. Murrelet 49:38. and Alaska Peninsula. U.S. Fish Wildl. Serv., N. Carlquist, S. 1965. Island life: a natural history of Am. Fauna 61:1-364. the islands of the world. Natural History Press, Norman, F. I. 1970. The effects of sheep on the New York. breeding success and habitat of the short-tailed Clark, A. H. 1910. The birds collected and observed shearwater (Puffinus tenuirostris) (Temminch). during the cruises of the United States Fisheries Aust. J. Zool. 18:215-242. Steamer "Albatross" in the North Pacific Ocean Odum, E. P. 1971. Fundamentals of ecology. W. B. and in the Bering, Okhotsk, Japan, and Eastern Saunders Co., Philadelphia, Pa. 574 pp. seas from April to December 1906. Proc. U.S. Rausch, R. 1958. The occurrence and distribution of Natl. Mus. 38:25-74. birds on Middleton Island, Alaska. Condor Couch, L. K. 1929. Introduced European rabbits in 60(4):227-242. the San Juan Islands, Washington. J. Mammal. Richardson, F. 1961. Breeding biology of the rhi- 10:334-336. noceros auklet on Protection Island. Condor Gabrielson, I. N., and F. C. Lincoln. 1959. The birds 63(6):456-473. of Alaska. Stackpole Co. and Wildlife Manage- Sherwood, G. A. 1968. Factors limiting production ment Institute, Washington, D.C. and expansion of local populations of Canada Harris, M. P. 1970. The biology of an endangered geese. Pages 73-85 in R. L. Hine and C. Schoen- species, the dark-rumped petrel (Pterodroma feld, eds. Canada goose management. Dembar phacopygia) in the Galapagos Islands. Condor Educational Research Service, Madison, Wis. 72:76-84. Tikhmenev, P. 1861. Historical review of the origin Howell, T. R., and T. J. Cade. 1954. The birds of of the Russian-American Co. and its activity up Guadalupe Island in 1953. Condor 56:283-291. to and the present time. Edward Weimar, St. Imber, M. J. 1974. The rare and endangered species Petersburg. of the New Zealand region and the policies that Tomich, P. Q., N. Wilson, and C. H. Lamoureux. exist for their management: petrels and preda- 1968. Ecological factors on Manana Island, tors. Paper presented to the International Coun- Hawaii. Pac. Sci. 12:352-368. cil for Bird Preservation (XVI World Conference), Warner, R. E. 1963. Recent history and ecology of Canberra. the Laysan duck. Condor 65(l):2-23. Oil Vulnerability Index for Marine Oriented Birds

~~James G. King U.S. Fish and Wildlife Service P. O. Box 1287 Juneau, Alaska 99802 and Gerald A. Sanger U.S. Fish and Wildlife Service Anchorage, Alaska~~

~~Abstract~~

~~The 176 species of birds using marine habitats of the Northeast Pacific are~~

graded on the basis of 20 factors that affect their survival. A score of 0, 1, 3, or 5, respectively, representing no, low, medium, or high significance is assigned for each factor. The total score is the Oil Vulnerability Index (OVI). The OVI's range

from 1 to 100, an index of 100 indicating the greatest vulnerability. Using this system, one can rank the avifauna of different areas according to their vulnerability to environmental hazards as an aid in making management decisions.

Today's decision makers require an ever-in- The need for a system to evaluate relative creasing array of information and planning vulnerabiUties of bird populations is particu- documents. The Federal Government's re- larly great for birds that are being increas- quirement for environmental impact state- ingly affected by marine oil pollution. The sys- ments under the National Environmental Pro- tem needs to allow comparisons of potential tection Act of 1969 is but one example of this impacts to birds resulting from various oil de- trend. These documents generally consider velopment projects in different locations and the effects of proposed actions on waterfowl served by various modes of transport. The Oil and a few other species of birds, but the bulk VulnerabiUty Index (OVI) is our attempt to fulfill on the avifauna of the avifauna is usually only Usted, or some- this informational need know, times ignored completely. A simple system of the Northeast Pacific. Insofar as we this approach to assessing a wildlife manage- for evaluating and presenting avian data is ment problem has been attempted only for badly needed so that those interested in birds, ranking endangered species in a numeric rank- whether technically trained or not, can easily ing system that identified where restoration grasp the implications of proposed actions. It efforts could best be directed (Sparrowe and is incumbent on biologists to devise new ways Wight 1975). of presenting their knowledge so that it can be We are indebted to Gene Ruhr and Keith easily and effectively used by decision Schreiner for ideas generated in their work makers, who are often less informed. In short, with endangered species. Frank Pitelka, biologists must do for the environmental im- James Bartonek, Kent Wohl, and Mary Lou pact statement assessors what Roger Tory King reviewed portions of the manuscript and Peterson did for the bird watchers by giving offered helpful suggestions. Jack Hodges them a simple and comprehensible system. helped prepare the OVI tables.

~~227 228 J. G. KING AND G. A. SANGER~~

~~Methods Results~~

A list of 176 species of birds using marine The OVI for each of 176 bird species is habitats in or near the States of Washington listed in Table 1. The average OVI for 22 and Alaska and the Province of British avian families comprising 128 species that are

Columbia (Table 1, left column) was compiled neither rare stragglers nor endangered ranged from checklists by the American Ornitholo- from 19 to 88, with a mean of 51 (Table 3). gists' Union (AOU 1957) and Gibson (1970). Tables 4 and 5 show a possible use for the Nomenclature is from AOU (1957). The scien- OVI by comparing impacts in two large, tific names of three species of shorebirds re- widely separated areas. A species Ust from cently identified in the Aleutian Islands that Southeast Alaska (U.S. Forest Service and were not listed by the AOU (1957) came from Alaska Department of Fish and Game 1970) is Peterson etal. (1967). compared with a list from the Aleutian Is- lands (U.S. Fish and WildUfe Service 1974). Each bird was scored on 20 /actors that af- Only commonly occurring species are in- fect its survival (Table 1). Point scores for cluded. These tables graphically display most birds were either 0, 1,3, or 5, indicating rather strong differences in the vulnerability no, low, medium, or high importance, respec- of the avifauna of each area. A person explain- tively, in their biology or habits as related to ing comparative impacts of projects might Northeast Pacific oil development. Rare or use the tables in the following way: accidental species were given only one point • Column 1, with scores from 1 to 20 points, for occurrence, and endangered species 99 indicates birds with a low level of project in- points for population size plus 1 point for oc- volvement, where damage or future costs currence. Thus the potential range of the would not be expected. As this will normally OVI's is from 1 to 100. be the longest list, as in Tables 4 and 5, one would expect an immediate rise of interest on The factors in Table are largely self-ex- the part of the planning agency, which is prob- planatory. The items under "range" apply to ably eager to learn where problems will be the entire world population of the species. fewest. "Productivity" is derived from a combination of clutch size and age at first nesting. Speciali- • Column 2 (21 to 40 points) indicates birds zation is used in the biological sense to com- for which there is a low level of concern. Per- pare a versatile species like mallards (Anas haps all that is needed is a review to deter- platyrhynchos) with a less versatile species mine if special characteristics of the project such as the trumpeter swan (Olor buccinator). might be detrimental to these species. Mortality under "history of oiling" is based on our knowledge that some species (e.g., al- • Column 3 (41 to 60 points) might be called cids) have been more involved others than "trial and error" species. If some birds are ad- such as gulls. Exposure relates to the level of versely affected, it will not be catastrophic. exposure within the Pacific area in any As the project develops it will be merely nec- season. essary to monitor these to make sure their

status is not adversely affected. If it is, there Information on many of the factors for will be time to develop conservation many species is scanty at best, and subjective measures. appraisals were made by us when information was lacking. Opinions as to appropriate • Columns 4 and 5 (61 to 80 points and 81 to scores will vary among experts. References 100 points, respectively) include the species used, in part, in preparing Table 1 were: AOU where concern is high. It is for these species 1957; Fay and Cade 1959; Gabrielson and that research money will be needed, where Lincoln 1959; Isleib and Kessel 1973; Kort- project modifications may be required, where right 1942; Murie 1959; Palmer 1962; Robbins a contingency plan in case of disaster is et al. 1966; Sanger 1972; and Stout et al. 1967. needed, where a conservation technology will OIL VULNERABILITY INDEX FOR MARINE ORIENTED BIRDS 229

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~~234 J. G. KING AND G. A. SANGER~~

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~~Table 2. Criteria and points used in calculating Oil Vulnerability Index.~~

~~Point assignment~~

1 3 5 Range Breeding Large Medium Small Migration Long Medium Short Winter Large Medium Small Marine orientation Coastal zone Intertidal Open water Population Size Large Medium Small Productivity Large Medium Small Habits Roosting Shore Drift Water Foraging Walking Flying Swimming Escape Leave area Fly Dive Flocking Small Medium Large Nesting density Low Medium High Specialization Low Medium High

Mortality Hunted by man Low Medium High Animal depredations Low Medium High Non-oil pollution Low Medium High History of oiling Low Medium High Exposure Spring Low Medium High Summer Low Medium High Fall Low Medium High Winter Low Medium High

be needed, and where periodic project shut- Of prime importance is the system's sim- down could be called for. plicity. The use of four levels of value for each With these points in mind it is immediately factor, instead of five or more, is an attempt obvious that Southeast Alaska (Table 4), to simpUfy. Ian McHarg (1969) has shown which has only 9 high-score birds, offers far that extremely complex land-use values can less potential for bird problems than does the be graphically compared and displayed by

Aleutian area (Table 5), which has 24 high- using three levels in a way that is useful to score species. The planning agency could decision makers. The difficulty of using more make some immediate decisions on site priori- levels of value was indicated by Sparrowe and ties and research funding based on such in- Wight (1975) who used up to 10 levels, enor- formation. mously complicating the problem of deaUng with low-quahty information, which is often Discussion all that is available. The use of scores of 0, 1, 3, 5 instead of 0, 1, 2, 3 for 20 factors enabled We are convinced that the OVI principle ex- us to use the convenient 100 points instead of pressed here will become a useful manage- 60 points as the maximum potential total ment tool with all sorts of possible applica- score for any species. tions. We recognize some difficulties with the The 20 factors that were evaluated are ad- present version, but believe it is timely to pre- mittedly arbitrary; with refinement and more sent the system so that a broader range of detailed data they could be adjusted to show thought, improvements, and application can better separation between affected species. be appUed to it. The decision to use 20 factors instead of more 236 J. G. KING AND G. A. SANGER

~~Table 3. Oil Vulnerability Index (OVI) for families of birds of the Northeast Pacific marine habitats, excluding rare and endangered species in the scoring.~~

~~OVI per species Number of Family species Total OVI Average Range~~

Loons— Gaviidae 4 219 55 47-65 Grebes — Podicipedidae 3 148 49 44-56 Albatrosses — Diomedeidae 2 102 51 50-52 Shearwaters— Procellaridae 4 208 52 47-57 Storm-petrels— Hydrobatidae 2 130 65 63-67 Cormorants— Phalacrocoracidae 4 235 59 52-63 Herons—Ardeidae 1 29 29 29 Wa terfowl — Anatidae 33 1,765 53 32-78 Eagles and Hawks— Accipitridae 2 77 39 19-58 Ospreys— Pandionidae 1 37 37 37 Falcons— Falconidae 1 41 41 41 Cranes—Gruidae 1 24 24 24 Rails and Coots— Rallidae 1 33 33 33 Oystercatchers— Haematopodidae 1 65 65 65 Plovers— Charadriidae 7 287 41 26-57 Sandpipers— Scolopacidae 22 857 39 24-59 Phalaropes — Phalaropodidae 2 120 60 58-62 Jaegers and Skuas— Stercorariidae 3 123 41 39-43 Gulls and Terns— Laridae 16 730 46 32-66 Auks— Alcidae 15 1,164 78 70-88 Kingfishers— Alcedinidae 1 28 28 28 Crows— Corvidae 2 68 34 21-47 Total and Mean 128 6,490 51 19-88

or less again relates to simplicity. This ap- evaluating the various factors, our scoring pears to be the minimum number that will as- was conservative. Experts on the various sure species separation and that can be neatly avian families can doubtless refine the scor- displayed. ing. If this system proves useful, investiga- The system will be much more useful when tors will begin to acquire the information it is expanded to the subspecific level. Many needed for more precise evaluations. Ultimate Holarctic species are represented in the perfection may never be achieved; however, as Northeast Pacific by a single race that would with the field guides, the fact of minor profes- have a much higher OVI than the species as a sional disagreement should not destroy the whole. For example, the OVI for the Peale's system's utility. peregrine falcon (Falco peregrinus pealei) con- We believe rescoring of all birds on the basis fined to marine habitats within the Pacific re- of various projects should be avoided because gion would be high; and the endangered Aleu- a standard against which individual projects tian Canada goose {Branta canadensis leuco- can be measured is needed. If everyone did pareia) would score 100 points instead of the their own scoring, there would be no standard, 34 we show for Canada geese (B. c). If Tables and projects evaluated by different investiga- 4 and 5 showed subspecies, the differences in tors would not be comparable. If a species list value would be more marked. for the project area and standard point scores Tables 4 and 5 are for broad geographical are used, the level of involvement for many areas. A comparison between smaller areas species and perhaps for most species will be would probably show more dramatic dif- properly identified. As with any system, there ferences. will be exceptions and the assessor will need Because the dearth of easily available, ap- to deal with these as appropriate. The result plicable information poses a problem in will still be to focus attention on those species OIL VULNERABILITY INDEX FOR MARINE ORIENTED BIRDS 237

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~~238 J. G. KING AND G. A. SANGER~~

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and impacting factors where it is most Gibson, D. D. 1970. Check-list of the birds of needed. Alaska. Univ. of Alaska, Fairbanks. 2 pp. Isleib, M. E., and B. Kessel. 1973. Birds of the We have used our OVI system to show the North Gulf Coast-Prince William Sound region, vulnerabihty of birds to oil, but it seems likely Alaska. Univ. of Alaska Biol. Pap. 14. 149 pp. that the vulnerability index could be applied Kortright, F. H. 1942. The ducks, geese and swans a broader scale to help make deci- on much of North America. Wildlife Management Insti- re- sions in other areas of human activity and tute, Washington, D. C. source development. The vulnerability index McHarg, I. L. 1969. Design with nature. Natural system could be applied to terrestrial as well History Press, Garden City, N. Y. 197 pp. as aquatic species by adding or subtracting Murie, O. J. 1959. Fauna of the Aleutian Islands impacting factors, as appropriate. Indexes re- and Alaska Peninsula. U.S. Fish Wildl. Serv., N. lating the impact of man upon each North Am. Fauna 61:1-364. Palmer, R. S. 1962. Handbook of North American American species could have broad uses in the birds. Vol. 1. Yale University Press, New Haven, field of conservation. Population explosions, Conn. 567 pp. as well as declines, might be predictable. Peterson, R. T., G. Montfort, and P. H. D. Hallom. Human activity could be better adjusted to 1967. A field guide to the birds of Britain and favor or depress wildUfe populations, as Europe. Houghton Mifflin Co., New York. appropriate. Robbins, D. S., B. Bruun, and H. S. Zimm. 1966. Birds of North America, a guide to field identifi- We believe that this vulnerability index sys- cation. Golden Press, New York. for aiding in the decision- tem has promise Sanger, G. A. 1972. Preliminary standing stock and making processes upon which future bird con- biomass estimates of seabirds in the subarctic servation will depend. Pacific region. Pages 589-611 in A. Y. Takenouti

et al., eds. Biological oceanography of the North Pacific Ocean. Idemitsy Shoten, Tokyo. Sparrowe, R. D., and H. M. Wight. 1975. Setting References priorities for the endangered species program. Proc. N. Am. Wildl. Nat. Resourc. Conf. 40:142- American Ornithologists' Union. 1957. Check-list of 156. North American birds. 5th ed. Lord Baltimore Stout, G. D., P. Matthiessen, V. R. Clem, and R. S. Press, Baltimore, Maryland. Palmer. 1967. The shorebirds of North America. Fay, F. H., and T. J. Cade. 1959. An ecological Viking Press, New York. 270 pp. analysis of the avifauna of St. Lawrence Island, U. S. Fish and Wildlife Service. 1974. Birds of the Alaska. Univ. CaUf. Publ. Zool. 63(2):73-150. Aleutian Islands National Wildlife Refuge. Wash- Gabrielson, L N., and F. C. Lincoln. 1959. The birds ington, D. C. of Alaska. The Stackpole Company, Harrisburg, U. S. Forest Service and Alaska Department of Pa., and Wildlife Management Institute, Wash- Fish and Game. 1970. Birds of Southeast Alaska, ington, D. C. 922 pp. a check-list. The agencies, Juneau, Alaska. 12 pp.

~~PROGRAMS AND AUTHORITIES RELATED TO MARINE BIRD CONSERVATION~~

~~Programs and Authorities Related to Marine Bird Conservation in Washington State~~

~~Ralph W. Larson Washington Department of Game 600 North Capitol Way Olympia, Washington 98504~~

~~Abstract~~

~~Seabirds are one of the most visible biological components of ecosystems, and yet little is known about them. They could readily be used as an index of marine~~

environmental quality if adequate studies were conducted to determine populations, habitat needs, and causes of fluctuations in abundance. The lack of adequate funding at the State level has precluded necessary studies to make these determinations and to provide habitat protection and preservation. The State of Washington has developed a funding source for protection, preservation, and enhancement of nongame wildlife, which includes seabirds. The sale of personalized license plates for vehicles is now providing some funds for nongame wildlife management—funds which should increase as the popu- larity of the licensing program increases. Outdoor Recreation Bonds are providing funding for habitat preservation. Authorities provided the Washington Game Department are adequate to manage and protect seabird species. Other State laws offer additional protection to their habitat— specifically the Shoreline Management Act of 1971 and the State Environmental Act.

It has been often stated that seabirds are Studies in Oregon have indicated that con- one of the most visible biological components sumption of pelagic fish by murres {Uria spp.), of ecosystems, and yet little is known about cormorants {Phalacrocorax spp.), storm- them. Most studies to date have been on fish, petrels {Oceanodroma spp.), and shearwaters and because of their recreational and commer- {Puffinus spp.) account for about 22% of the cial value, the concern for maintaining the annual production of various species of these marine environment has been primarily a re- fish. A decline in this food source will reflect a sult of the concern for maintaining the fishery decline in the seabird population. Why then resource. The visible knowledge of the fishery should it be necessary to use only fish popula- resource, however, becomes an "after-the- tions as an index of marine environmental fact" knowledge since the status of the stocks quaUty, when seabirds can more readily be ob- relates to the value and amount of the served and can reflect the same changes that fishery— a fishery resulting from survival occur? under the surface in the marine environment As a pubUc wildlife agency, the Washington that can be very secretive about its quaUty Department of Game is often attempting to until it is too late to do something about it. justify the value of seabirds, and sometimes Seabirds, however, are visible above the sur- that is not easy. When fishermen complain face, in numbers that can reflect changes in that the seabirds are eating all of the food of the marine environment that occur below the our mighty salmon, and hunters indicate little surface, since many depend on the subsurface compassion because the birds have no value quality that reflects populations of fish. to sport hunting, one has to think a httle to

~~243 a~~

~~244 R. W. LARSON~~

explain their value. However, rhinoceros auk- these birds and others. lets (Cerorhinca monocerata) do drive herring During the 1975 legislative session we were into ball-shaped schools, which attracts sal- successful in amending the personalized mon in search of food— which in turn provides Ucense program to include automobiles other a signal to fishermen that salmon may soon be than passenger cars— a step which should in the area. Explaining value to the hunter is a further enhance our funding. We anticipate bit more difficult, but anyone who has taken that funding will increase from the sale of the time to go out on our marine waters and these license plates each year. They serve as observe the many species of seabirds and their own advertisement, and as more plates watch them flying and feeding cannot help are sold, the exposure to the public increases. but be fascinated by them. The flight of thou- We anticipate that within the next few years sands of murres skimming over the water sur- the funding should reach $150,000 per year— face and somehow managing not to dash modest sum to be sure, but nevertheless ade- headlong into a wave is a fascinating sight. quate to establish a viable program. We who are in fish and wildlife work have We have been involved in studies funded had to readjust our thinking and values dur- through other agencies that involve seabirds. ing recent years. Our primary programs and The principal reasons for the studies are not concerns for many years were with the fish, seabirds, but they become an integral part of birds, and animals that were of value to fisher- any analysis that must be made of our salt- men and hunters. Species of wildlife that we water environs. One such study involves a now classify as nongame received incidental comprehensive status survey of the marine benefit from programs related to game fish, shoreline fauna of Washington. The Depart- game birds, and game animals, but we did not ment of Ecology has provided the funding as do badly in maintaining and enhancing these a part of their analysis of resources that may incidental wildlife species, mostly by indirec- be adversely affected by oil spills and eco- tion. However, in the last few years our De- nomic development of our shorelines. This partment, at least, has taken on a new respon- study will be the first one designed to compre- sibility and a new look as related to nongame hensively identify wildlife species associated wildUfe. with our shorelines and will determine the Our first positive step in this direction was species, their status, location, and habitat. to develop a funding source for nongame wild- This study will provide a basis for readily life programs. Our funding attempt charted identifying visually the results of oil spills and its way through stormy waters, but finally of the economic development of critical habi- ended up being voted on by the citizens of the tat areas, and provide sound basic data for State. Our citizens passed Referendum 33, use in combating destructive projects in the which provided funds to the Department for marine environment. nongame wildlife programs from the sale of We are finding that you cannot separate personalized license plates. Although the functions of other governmental agencies that funds have not been adequate, they are a step deal with marine waters from seabird analy- in the right direction and have permitted the sis. Pollution responsibilities, shoreUne man- Department to engage in a modest program of agement, coastal zone management, clam research and management. We have placed dredging, channel dredging, erosion control, one person in charge of our program to do the housing development, industrial expansion, planning and programming so necessary for shipping port development— to name a few- developing an effective, growing program. all must have some effect on our seabird During the 1st year of operation, we con- species. Therefore, we must concentrate on tracted studies on the rhinoceros auklet, the obtaining an adequate data base to insure the tufted puffin {Lunda cirrhata), and the black perpetuation of these valuable marine species. oystercatcher (Haematopus bachmani). These As I indicated earlier, the Department of studies have provided a basic knowledge of Game has not had a special program to man- some of the problems facing these seabird age seabirds in the past, but this should not species. As funds increase, additional studies indicate that we have not assisted in main- will be made to provide more information on taining the seabird resource. Our basic land MARINE BIRD CONSERVATION IN WASHINGTON STATE 245

acquisition program designed for waterfowl taking them (or to prohibit taking them), and enhancement has benefited seabirds. We now to create game reserves and closed areas own some 15,500 acres of lands, tideland, and where necessary to protect various species. marshes bordering the marine waters (includ- Our authorities also include the obligation to ing our Skagit and Nisqually holdings) which enforce the laws, rules, and regulations per- provide habitat and protection for many sea- taining to the protection of all wild birds. birds. We also recently acquired 48 acres on The Department may also acquire land for Protection Island, designed to protect the habitat and for sanctuaries for nongame birds nesting area of the rhinoceros auklet. This and may exchange lands for these purposes. purchase was an excellent example of how We may also enter into agreements with the combined efforts of several groups accom- Federal Government, persons, and municipal plished a nearly impossible goal. subdivisions of the State for all matters relat- Protection Island had been subdivided for ing to propagation, protection, and conserva- summer home development and many lots tion of all wild birds, and may lease State had been sold. The developer, however, got lands for this purpose. caught in the requirements of our Shoreline We believe our authorities are now totally Management Act with his last subdivision. adequate to satisfactorily manage the State's The uproar caused due to the use of this submarine bird resources. division by auklets created an atmosphere In addition to our personalized license plate that made subdivision a real conservation legislation, which earmarks funds for non- issue. The outspoken critics of the project game wildlife, other State laws and programs from the Audubon Society, Fish and Wildlife assist in protection of this resource. One pro- Service,' independent conservationists, and gram that has assisted materially in provid- our Department enlisted the aid of Nature ing funds for habitat acquisition is a bond Conservancy to negotiate for purchase of this issue passed by citizens of the State designed subdivision, and after lengthy negotiations to acquire and develop recreational land in the the option was obtained, and the Department State for public use. Our Interagency Com- purchased the land from the Nature Conser- mittee for Outdoor Recreation provides the vancy with funds provided by the Inter- necessary mechanism for funding of projects, agency Committee for Outdoor Recreation. using these bond monies to match Federal The area now is destined to be a seabird sanc- funds. Although recreation is a key factor in tuary, with limited public viewing and inci- obtaining funding, it is still possible to ac- dental recreation use. This project is an excel- quire key habitat for wildlife and develop a lent example of the power of cooperative ef- people-use program around the primary pur- forts by conservationists to protect a pose for acquisition. resource. The purchase of a portion of Protection Is- The State of Washington now has a reason- land was accomplished by use of these funds, ably good legislative base to insure construc- as I indicated earlier, and we are now working tive programs for management of our seabird again with Nature Conservancy to acquire resource. Our legislative authority lies in key bald eagle habitat on the Skagit River in State statutes under Title 77. These authori- northwestern Washington. The bond issues ties first provide that the wild birds, wild ani- total some $50 million, of which this Depart- mals, and game fish of the State are the prop- ment receives about 15%. The State now is in erty of the State and that they shall be pre- its third bond issue, and we hope the citizens served, protected, and perpetuated. Any regu- will continue to support this program. lations for taking shall be designed so as to One of the newer laws is the Shoreline Man- not "impair the supply thereof." agement Act of 1971. This act provides for de- The commission also has the authority to velopment of comprehensive shoreline man- classify wild birds. Seabirds, other than agement programs designed to control the de- hunted species, fall into the category of non- velopment of these areas to insure protection game birds. We also have the authority to of the public interest, while still recognizing regulate the propagation and protection of and protecting private property rights consis- wild birds, develop rules and regulations for tent with this public interest. These plans 246 R. W. LARSON

must be developed with citizen involvement. planning phase of the proposed project. Shoreline classification generally falls into The Department feels that our authorities four categories— natural, conservancy, rural, at this time are adequate to protect marine and urban. The natural classification can ac- bird populations and their habitat. The one complish the most substantial benefit for lacking factor, as usual, is the funding for marine birds. Provisions are also made for both adequate management programs and protection of "shoreUnes of statewide signifi- habitat protection. Our marine habitat is cance." Plans for these areas must give pref- rapidly being developed for recreational erence to uses favoring the public and long- homesites and pubUc use which can eliminate range goals. These shorelines cover the areas key habitat use. A greater public awareness of between low and high tide levels on inland the needs of marine birds can be a help in pre- waters and high water and the western bound- venting destruction of their habitat; however, ary of the State on our Pacific Ocean coast. money talks the loudest. The acquisition of Our State Environmental Policy Act, which these key habitats is the most positive means requires that environmental impact state- of insuring their retention. We have no solu- ments be prepared for various programs and tion at this time to the funding problem and developments, gives our Department an op- only hope that someone smarter than we are portunity to insure that our valuable wildlife can provide an acceptable solution before all resources are given consideration during the of our efforts become too Uttle and too late. Programs and Authorities of the Province of British Columbia Related to Marine Bird Conservation

~~W. T. Munro British Columbia Fish and Wildlife Branch 300-1019 Wharf Street Victoria, British Columbia, Canada V8W 2Z1 and~~

~~- R. Wayne Campbell J British Columbia Provincial Museum Victoria, British Columbia, Canada~~

~~Abstract~~

British Columbia Provincial agencies are given authority for protecting marine birds and their habitats by the Provincial Wildlife Act, the Parks Act, and the Ecological Reserves Act. The Provincial Museum Act accommodates research on marine birds. The Fish and Wildlife branch has protected over 30,000 ha of intertidal estuarine habitat in the form of reserves and has conducted limited inventories of birds on the Queen Charlotte Islands and northern mainland coast. The Provincial Museum has conducted inventories and life-history studies of marine birds and maintains a repository for information on seabirds, including a catalog of colonies. Pollution from oil and chemicals, improper logging practices, and disturbance by boating recreationists are the most apparent threats to the well- being of birds. Additional inventories and the determination of seasonal distribution are among the information needed to better protect the marine birds of British Columbia.

Most marine-associated birds in Canada are British Columbia's irregular shores provide covered by the Migratory Birds Convention thousands of kilometers of coastUne, much of Act and are therefore federally protected. In which is used by marine birds for nesting and British Columbia additional protection is pro- wintering as well as during migration. vided by the Provincial WildUfe Act. Several Through legislation of different types, some of other provincial acts provide authorities re- the more ecologically important and unique lated to seabirds. The Provincial Museum Act sites have been protected. Twelve "ecological permits research related to natural history; reserves," which are basically inviolate pre- the Parks Act and Ecological Reserves Act serve areas, provide habitat for and protec- provide for the protection of habitat and pro- tion to a number of major breeding colonies. hibit harassment of wildlife within park and Over 30,000 ha of intertidal estuarine habitat reserve boundaries; and the Firearms Act per- has been protected by the provincial Fish and mits the closure of areas frequented by se- Wildlife Branch in the form of reserves. Less lected wildlife to the discharge of firearms. than half of the total area is in Order-in-Coun- The fact that several authorities for the pro- cil reserves (passed by the Provincial Cabi- tection and conservation of marine birds are net), which afford strong protection; the rest available does not mean that they have been is in departmental map reserves, which used to full advantage. merely means other agencies must inform the

~~247 248 W. T. MUNRO AND R. W. CAMPBELL~~

branch before they disturb them; they are More recently, precise counts have been ob- hardly secure. Provincial Parks Branch pro- tained of seabirds nesting in the Strait of tects other areas used by marine birds by in- Georgia, Juan de Fuca Strait, the central west corporating them within parks. coast of Vancouver Island, the northern main- Research and conservation of seabirds in land coast, and the east coast of the Queen British Columbia have not been a high Charlotte Islands. That information, along priority in the Fish and Wildlife Branch, basi- with quantitative data gathered in the sum- cally because seabirds are not consumed by mer of 1975, will be used to update the "Cata- people. Our primary interest in seabirds has logue of British Columbia Seabird Colonies" been in their role as a life support system for published in 1961 by the museum. the peregrine falcon {Falco peregrinus). Most The museum has a number of programs Fish and Wildlife Branch reserves have been under way. established to protect estuarine habitat for • A cooperative survey with Washington fishes, waterfowl, and shorebirds rather than State of colonies of the double-crested cor- for true seabirds. That situation is not likely morant {Phalacrocorax auritus) in the Pacific to change in the near future unless additional Northwest. To limit disturbance, that survey funds become available to the Branch. About is to be conducted at 5-year intervals begin- the most we can expect to do is designate key ning in the summer of 1975. areas as sanctuaries or wildlife management • A survey of all islands, whether or not reserves. Under the folio and referral systems they are supporting seabirds, in the Strait of now operational among resource agencies in Georgia and Juan de Fuca Strait in 1980, to British Columbia, we have the opportunity to detect changes in populations after 1974. advise other disciplines against approving • Monitoring changes in seabird populations practices that would adversely affect wildlife. along the west coast of Vancouver Island, By those methods we are attempting to pro- gathering data for all islands there. Perma- tect critical seabird habitat. It must be nent quadrats will be established on ecologi- stressed, however, that we can only advise; we cal reserves in the area to help detect such cannot force other agencies to follow pro- changes. As a result of such quadrats having cedures we suggest. been set up in 1967 on Cleland Island and The only significant work relating to sea- being re-examined in 1974, we can document a birds in which the Fish and Wildlife Branch is significant decrease in Leach's storm-petrel presently engaged involves inventory of (Oceanodroma leucorhoa) and a corresponding specific sites on the Queen Charlotte Islands increase in rhinoceros auklet (Cerorhinca and the northwest mainland coast. Those monocerata). areas are ones on which we expect to find sea- • Mapping vegetation substrate as it relates bird colonies and where applications for log- to seabird populations on selected islands in ging are pending. To enable us to advise the the Province.

Forest Service on the wildlife values of those • Investigating differences in eggshell thick- sites, we began field work in the summer of ness between eggs within clutches of glau- 1975. cous-winged gulls (Larus glaucescens) near The Federal Government, in comparison to Victoria. what it has done on the east coast and in the • A saturation banding program for cor- north of Canada, has been negligent in its sup- morants (Phalacrocorax penicillatus, P. pela- port of seabird conservation on the west gicus, and P. auritus) on south-coast colonies. coast. By far the most seabird research by a • Continued banding of select colonies of government agency in British Columbia has glaucous-winged gulls which began in the been accomplished by the staff at the Provin- 1960's. Life tables, survivorship curves, and cial Museum in Victoria. In the past, begin- dispersal patterns should result. ning in the 1940's, museum personnel (mainly The museum also acts as a repository for in- C. J. Guiguet) explored and inventoried sea- formation on seabirds in British Columbia bird colonies along the British Columbia and maintains files on the history of seabird coast. Most work then was exploratory, and islands as well as references to literature pub- little quantitative information was gathered. lished on all seabirds in the Province. The ref- MARINE BIRD CONSERVATION IN BRITISH COLUMBIA 249

erences include unpublished theses and re- existence of seabird populations. The recent ports. This information is easily retrievable— unauthorized and apparently unsuccessful in- not a small contribution in today's paper-pro- troduction of mink on the Queen Charlotte Is- ducing society. lands could have resulted in the eventual Future programs planned by the Provincial devastation of seabird colonies there and on Museum, in addition to the continuance of adjacent islands. The destruction of habitat some of those already mentioned, include a by logging near colonies on large islands and system of monitoring colonies every 5 to 10 complete logging on small offshore islands years, depending on the sensitivity of the will no doubt adversely affect some seabird species involved, to detect changes in popula- populations. Competition between increasing tion numbers and distribution. It is also numbers of gulls (Larus spp.) and certain hoped that the first complete provincial cen- species of seabirds (e.g., storm-petrels and sus, with cooperation from Federal and pro- cormorants) may result in reduced numbers of vincial agencies, naturalist groups, and the the seabirds. like, can be budgeted and arranged for in the What types of programs are needed? About summer of 1980. That census could conceiv- 80% of all known seabird colonies in British ably be expanded to include the entire Pacific Columbia have been investigated to date, and coast of North America. a modest program to monitor changes has Some research on the breeding biology of been estabUshed. We do, however, require ex- seabirds has been conducted by universities, ploratory work along the west coast of the notably the University of British Columbia Queen Charlotte Islands and northern main- under the guidance of R. H. Drent and M. Ud- land coast. We need to know more about the vardy. We expect that graduates returning to breeding biology and reproductive potential coastal universities will continue that work. of each of the species nesting in the Province, The section of government dealing with eco- as well as about their adaptabihty to different logical reserves has just recently received habitats. Will some burrow-nesting alcids use funding to permit field studies on reserves man-made tubes erected in otherwise mar- harboring marine birds. J. B. Foster, Coordi- ginal habitat? Can and should more man- nator of Ecological Reserves, emphasizes that made habitat be created for cormorants that research by other agencies is encouraged have been displaced from ancestral breeding under permit on ecological reserves. grounds? There are a number of threats to seabirds in Of immediate urgency is exploratory work British Columbia. Along with the chemical involving seasonal distribution, abundance, pollutants in their environment and food, log- and flight lanes of pelagic seabirds along the ging, and the specter of huge oil tankers ply- coast of British Columbia— especially the ing the west coast, we are greatly concerned northern portion. We lack the base-line data by the potential threat of boating enthusiasts which could help influence routes of oil and recreationists. Well-meaning but unin- tankers to lessen the potential danger of spills formed vacationers and boaters stopping to to marine birds. We know httle about the win- visit or picnic at seabird islands can do serious ter distribution of marine birds, especially damage to nesting seabirds. The possibiUty of alcids. loss of habitat to seabirds from people search- As a general rule, offshore islands of less ing for island summer homes poses a threat, than 100 ha should be protected completely and indeed some seabird islands have already from logging, and the larger ones supporting been lost to speculators. With increased major seabird colonies should have some pro- leisure time and travel the potential of unin- tection from development. We must also con- tentionally introducing predators, such as sider the possibiUty of preserving some is- rats (Rattus spp.) and snakes, to seabird islands which may act as buffer areas and pro- lands is great. Intentional or accidental intro- vide potential alternate habitat to seabirds. duction of mammals, such as mink {Mustella Another concern is the effect of commercial vison), rabbit {Sylvilagus spp.), fox {Vulpes and sport fishing in the Province on food sup- fulva), and raccoon (Procyon lotor), to islands pUes for seabirds, and what damage, if any, is another serious threat to the future gillnetting may have on diving seabirds. Per- 250 W. T. MUNRO AND R. W. CAMPBELL

haps we should discourage fishing by nets in populations of glaucous-winged gulls in areas where large numbers of seabirds aggre- British Columbia have increased exponen- gate to feed. tially in the past 10 years. If they are a threat We also need to know more about the ef- to the existence of other seabirds (e.g., fects of chemical pollutants on individual Leach's storm-petrel, double-crested cor- species and on their reproduction. Of para- morants), should they be controlled, and, if so, mount importance, and one which biologists how? Such meetings would also help develop a tend to neglect, is communication among all pattern of universal census methods and tech- disciplines interested in seabirds. For niques that could be put to use along the example, a comprehensive file of the history Pacific Coast to provide comparable data of seabird colonies in British Columbia is es- from different areas. tablished at the Provincial Museum. It would Finally, in today's world, natural resource be a waste of time and money to dupUcate agencies must operate on limited funding. that file and have three or four scattered How can one convince administrators to di- across the country. We would be better ad- vert a significant portion of those funds to the vised to tackle another phase of work yet to investigation of species that are widely re- be accomplished. Communication assures garded as having little social importance? that seabirds benefit and are not unduly bibliography of seabirds of harassed. A detailed British Columbia is available from either of Annual meetings, both local and interna- us. tional, of persons interested in marine birds should be arranged so that problems relating We thank D. F. Hatler, J. B. Foster, and to seabirds can be discussed. For example. A. L. Allen for comments on the manuscript. Petroleum Industry's Role in Marine Bird Conservation

~~Keith G. Hay American Petroleum Institute 2101 L Street NW Washington, D. C. 20037~~

~~Abstract~~

Despite improved safety practices, engineering, and navigational skills, marine tanker transportation will not be 100% accident free. The industry seeks to mitigate wildlife losses through improved technology, research in the rehabilitation

~~of species exposed to oil, and the development of oil spill/wildlife contingency plans.~~

Oil spills and marine birds not only consti- neering, and navigational skills. Unfortu- tute a deadly mix but have proved to be one of nately, the problem is the product of the in- our toughest environmental problems to herent fallibility of man and his imperfect solve. The rehabihtation of these tragic vic- machines. tims is plagued with controversy, emotion, We cannot ignore the situation. We must apathy, and biological unknowns. The costs here, as elsewhere, improve our technology have been high and the survival rates low. and mitigate the impact. During the last 10 years, a few dedicated A study of more than 100 spills that oc- people working here and in Europe have re- curred throughout the world between 1960 versed this trend. They have, in addition, and 1971 revealed that about 1 in 5 spills taken steps to develop contingency plans and (20%) involved 50 or more birds (Ottway conducted research to reduce seabird mortali- 1971). Nearshore spills have a far greater ef- ties from oil spills. I present a brief status re- fect on waterfowl than do spills occurring port on their progress and the melange of several miles or more offshore. problems involved. In the 1967 Torrey Canyon tanker spill, The unfortunate encounter between spilled some 8,000 oiled birds were rescued. About oil and marine birds is not new. It goes back 6,000 were picked up aUve in England and at least to the turn of the century, when coal- about 2,000 in France, at a cost estimated at burning steamships and sailing clippers were $160,000 (Clark 1969; Bourne 1970). Less replaced by oil-fueled vessels. Since then thou- than 5% of those treated by British authori- sands of marine birds have succumbed to ties survived for release some months later. floating oil, especially during World Wars I The survival rate of those rescued in France is and II (Blanks 1942) and in recent spills here unknown. and off the coast of Europe (Clark 1969). In 1969 the Santa Barbara spill resulted in With the current and projected demands for the treatment of 1,575 marine birds, of which energy in the United States and with ex- 169 were eventually released. Many of those panded tanker traffic and accelerated de- released were found dead within a short time velopment of offshore petroleum reserves, the (Small 1971). oil-contaminated ("oiled") bird is not going to In 1970 the tanker Delian Apollon was re- go away. Periodically, this ugly problem will sponsible for a spill in Tampa Bay, Florida. arise, despite the efforts of the petroleum in- Thousands of seabirds were lost. No exact dustry to improve its safety practices, engi- count was taken, but hundreds of birds were

~~251 252 K. G. HAY~~

cleaned and farmed out for rehabilitation. Re- spiU are imprecise; they may differ by thou- ports show that many of the birds were re- sands of birds. It is believed that only a small turned dead within a few days (Smithsonian fraction of the birds killed in a spill wash up Institution 1971). on the shore. Some authors have even specu- In 1971, when two tankers collided under lated that the death rate at sea could range the Golden Gate Bridge at the mouth of San from 6 to 25 times the number washed ashore Francisco Bay, the resulting spill involved (Tanis and Morzer-Bruyns 1968). some 4,686 oiled birds taken to cleaning cen- In contrast to terrestrial birds and semi- ters (Lassen 1972). Eight months later the aquatic species (e.g., ducks; geese; coots, last of 200 survivors (less than 5%) were re- Fulica spp.; or gulls, Larus spp.), totally sea- leased at a cost estimated at $900 per bird borne species have a restricted reproductive (Smith 1975). potential. Many, such as the alcids, do not The most vulnerable species involved in breed until they are 3 or more years old, and spills have been the oceanic birds such as the lay only one egg per year. Only one in five sur- alcids—murres {Una spp.), auks (Pinguinus vives to go to sea. spp., Alca spp.), puffins {Fratercula spp., Until about 5 years ago we knew Uttle about Lunda spp.), and guillemots (Cepphus spp.). seabirds. They are not game species (they Other species less affected included ruddy taste fishy) and thus do not constitute an im- ducks (Oxyura jamaicensis), scaup (Ay thya portant economic resource. They have never marila, A. affinis), scoters {Melanitta spp.), been the subject of intensive waterfowl man- mergansers (Lophodytes spp.), oldsquaws agement or research by either State or (Clangula spp.), and goldeneyes (Bucephala Federal governments. spp.). Grebes (Podiceps spp.), eiders [Poly- During the last 5 years a small group of sticta spp.), loons (Gavia spp.), and cor- people here and in England have been study- morants {Phalacrocorax spp.) are also fre- ing marine birds— their distribution, popula- quently involved. Ruddy ducks and scaup are tion status, physiology, diseases, and hus- particularly vulnerable during winter on large bandry in captivity. Four organizations have river systems with heavy oil transport traffic. primarily been involved: The American Petro- Fortunately, none of the above species have leum Institute (API); the Wildlife RehabiUta- been reported in jeopardy as a result of spills tion Center at Upton, Massachusetts; Eng- in American waters. land's Advisory Committee on Oil Pollution In Europe and South Africa, however, it is of the Sea; and the International Bird Rescue believed that oil pollution is responsible for a Research Center in Berkeley, California. They steady decUne in seabird colonies. For have encountered many common biological example, in known oil-dumping areas in the and people problems, some of which I discuss Baltic Sea, where some mortality of old- here. squaws has been associated with surface oil, their population has dropped to about one- tenth of the pre-World War II level (Bergman Biological Problems 1961). Other authors report that oil spills have reduced the number of scoters in the Bal- The recuperation record for oiled seabirds in tic and off southeast England (Atkinson- the past has admittedly been dismal. A few Willes 1963). The auk populations off the birds have been returned to nature, but only coast of England have been reported to be after a long and costly period of care. In the substantially decreased by oil pollution (Pars- process, semidomestication often takes place. low 1967). Tankers traversing South Africa's The percentage of cleaned birds that actually Cape of Good Hope are said to be responsible survive after release is even smaller. One for the reduction of jackass penguins, should not infer from this small percentage Spheniscus demersus (Rowan 1968). Oil pollu- that rehabiUtated birds cannot readjust to life tion, especially sustained pollution, has thus in the wild. Several successful reintroductions been cited as a limiting factor on certain sea- have been documented. U.S. Fish and Wildlife bird populations. Service bands were returned from two west- Estimates of seabird mortaUties from an oil ern grebes that were cleaned and released PETROLEUM INDUSTRY'S ROLE IN MARINE BIRD CONSERVATION 253

after the 1971 San Francisco spill. One bird Fletcher (1973) stated that many variables was picked up a year later near Treasure Is- affect bird survival: weather conditions, the land, California, and the second after almost 2 type and amount of oil in and on the bird, the years, in the State of Washington (Fletcher species, the distance of the spill from the 1973). shore, the time lag from initial fouling until Survival rates have zoomed with recent initial treatment, the degree of stress a bird is strides in cleaning technology and husbandry. subjected to, the husbandry techniques used, The International Bird Rescue Research Cen- the time of release (the sooner released, the ter reported a survival rate of 41%, based on higher the apparent survival), the number of hundreds of birds and about 20 different birds being cared for (the fewer birds being species over a 2-year period (Smith 1975). In handled, the higher the survival rate), the South Africa, where powdered clay was used quality of the facilities available, and the as a cleaning agent on jackass penguins, training and experience of the people handling nearly 50% survived, although exact percent- the birds. ages have not been published (Edwards 1963; Many of the above biological problems are Holmes 1973). Rapid retrieval, the relatively under study here and in Europe, including the small groups of birds treated, and expert following. cleaning and husbandry techniques are largely responsible for high success ratios. Re- • The effect of ingested oil on the mucosal habilitation success is measured not only in transport mechanism of marine birds. To use terms of percent survival but also in terms of seawater, birds must be able to transport median length of captivity and average cost sodium ions through the gut and expel the ex- per bird. cess salt through the nasal passages. Oil can Rescued oiled birds arrive at cleaning cen- block the mucosal ion transport mechanism, ters under a wide range of physical conditions. resulting in dehydration and eventual death. Before capture they may have spent hours or • The development of a successful program days- in water, during which their energy has of hormonal and electrolyte therapy to restore been continuously drained. The oil destroys osmotic balance and the functioning of the the bird's protective insulation, and metabolic salt glands in contaminated seabirds. rate must be increased to sustain body tem- • Treatment and prevention of aspergillosis perature. Constant preening also takes (fungus infection); septic arthritis or "bumble- energy. Food demands increase, but feeding foot" (joint capsule infections); breast sores attempts, especially for diving birds, are (especially in seabirds confined on hard sur- thwarted by oil-fouled plumage. A bird may faces); eye lesions (caused by anunonia fumes arrive at the cleaning center under stress, from unsanitary pens); dehydration and hypo- chilled, exhausted, dehydrated, starved, and glycemia; lipid pneumonia; and bacterial ill from ingested oil. Cold weather accentuates infections. these conditions. Often such birds are jam- • Treatment of stress after capture, includ- med together with other species, hauled long ing perfection of handling and cleaning tech- distances, and immediately put through a niques, administration of proper steroids, series of cleaning processes that would leave crowding, light, temperature, noise levels, and even a healthy bird weak and in a state of soon. shock. One marvels at the stamina of the • Development of proper nutritional re- survivors. gimes for certain species and feeding tech- In most past spills, every bird found was niques to eliminate forced feeding. routinely cleaned regardless of its condition. • The establishment of criteria for confident Instead of attempting to reclaim all birds, a recognition of terminal pathological condi- selective judgment should be made. If a bird's tions in oiled birds. physical condition makes its chances of sur- • Determination of optimum density of con- vival nearly impossible, it should be humanely fined birds to insure healthy conditions and killed (except for rare or endangered species). adequate room for preening. This would enable workers to devote more • Determination of proper time and condi- time and care to birds having a reasonable tions for reintroduction of the birds into their chance at survival. native habitat. 254 K. G. HAY

People Problems contact. • Clarification of the roles of State and Handling an over-responsive and emotional Federal agencies under the Regional Re- army of bird-cleaning volunteers and training sponse Plan of the National Oil and Hazar- them to play constructive roles is a major dous Substances Pollution Contingency Plan. undertaking. Planning, cooperation, under- • A list of State and Federal laws pertaining standing, patience, and clear direction must to possession of birds and mammals. be developed. In the absence of these virtues, • An updated roster should be maintained of chaos can and has prevailed. team members, assignments, and responsibili- The San Francisco Bay oil spill of 1971 was ties for inland and marine spills, including dis- a classic example. There was virtually no covery and notification, record keeping, pub- State or Federal coordination. SpUnter lic information, containment and counter- groups of volunteers established their own measures, wildUfe protection, and cleanup, "treatment centers" and jealously guarded restoration and evaluation of effects on the their patients. Some actually absconded with biota. their pet patients to seek better care else- • A list of individuals or organizations that where. Long hours, fatigue, and frustrations possess skills and experience in treatment of led to dissension and bitter quarrels. Anties- oiled birds (locally and nationally). tabhshment sentiment was rampant. • Location of emergency wildlife reception Instant experts on bird cleaning, avian and treatment centers. medicine, and nutrition appeared or developed • A list of the necessary suppUes, equip- overnight. Veterinarians volunteered their ment, and holding facilities for cleaning, treat- services, but their knowledge of oiled-bird ing, drying, and post-care operations. Such in- treatment was limited. A wide variety of food formation can be obtained from: (from canned dog food to live shrimp) was —CaUfornia Department of Fish and given the birds. Forced feeding was routine. Game, Oil and Hazardous Materials Medications and vitamins of all kinds were Contingency Plan (July 1974) also administered. Needless to say, the states —International Bird Rescue Research of the art in treating oiled birds and handling Center, Aquatic Park, Berkeley, CaU- volunteers were both in their infancy. For fornia 94710 both, the success ratio was near zero. —American Petroleum Institute, 2101 L To prevent such fruitless efforts and the Street, Northwest, Washington, D. C. frantic, unorganized response that prevailed, 20037 a well-designed contingency plan for wildlife —WildHfe Rehabilitation Center, 84 involved in an oil spill is needed. Grove Street, Upton, Massachusetts 01568

• An organizational plan which includes as- Contingency Planning signments of duties and responsibilities for personnel manning a bird-cleaning center. In It is only prudent to take reasonable meas- addition to bird cleaning and husbandry, as- ures to prepare for oiled-bird emergencies. signments must be made for record keeping, This is especially true in regions where bird internal communications, public relations, concentrations and oil shipment traffic con- logistics (supplies), security, sanitation, verge. Almost equal attention must be de- safety, and meals. voted to handling volunteers as to handling • A slide lecture or film to instruct volun- birds. Safety is a major consideration. The teers in the correct techniques for handling, sharp beaks of birds can be very dangerous. cleaning, and post-care of oiled birds. A model State contingency plan should in- • A selected bibliography of key references clude the following: on oiled-bird cleaning and care. • A list of State and Federal agencies to be • Appendices to the plan should include alerted, including 24-h, 7-day-a-week tele- maps of the major coastal oil terminals, bays, phone numbers, and names of individuals to and estuarine areas with heavy oil transport PETROLEUM INDUSTRY'S ROLE IN MARINE BIRD CONSERVATION 255

traffic. Map overlays would depict the loca- fornia at Santa Barbara. Under the direction tion of resident species and the migratory pat- of W. N. Holmes, the studies are directed at terns, species composition, relative abun- the effects of ingested crude oil and petroleum dance, and winter concentration areas of mi- products on marine birds. Holmes has re- grants. Additional overlays would locate com- vealed that small quantities of crude oil intro- mercially important demersal seafood areas duced into the gut of a saltwater-adapted bird (e.g., oyster and abalone beds, lobster and can affect the mucosal transport and extra- crabbing locales) and marine mammal habi- renal excretory mechanisms, resulting in tats. Further refinement of an atlas could in- acute dehydration and eventual death. Dr. clude information on tides, prevailing winds, Holmes is also examining the effects of the ocean currents, and water mass movements to various distillation fractions derived from assist in predicting the path of spilled oil. crude oil and the long-term effects of ingested oil in mature birds. Incidentally, Alaska North Slope oil was found to be almost in- What Been Accomplished Has nocuous when administered to ducklings in amounts similar to the effective doses of other The petroleum industry, through the API, oils (Holmes and Cronshaw 1975). took prompt steps to mitigate the problem Refined products (diesel oil. No. 2 fuel oil, after the first seabird mortalities were re- and Bunker "C") are known to be more toxic ported from Santa Barbara in 1969. They than crude oil. For example, the relatively commissioned a young aviculturist, Philip small spills of Bunker "C" at Tampa, Florida, Stanton, who has extensive experience work- in 1970 and in San Francisco in 1971 caused ing with wild waterfowl, to start a research approximate mortalities of 90 and 20 birds program on cleaning and caring for oiled per ton of spilled product, respectively. The birds. At his Wildlife Rehabilitation Center at crude oil spills of the Torrey Canyon and at Upton, • Massachusetts, Stanton, with the Santa Barbara, however, resulted in mortali- help of API, has been conducting research on ties of only 0.5 and 0.6 bird per ton of oil oiled birds for 7 years. He is also an assistant (Clark 1973). professor of biology at nearby Framingham Dr. Holmes is now testing measured State College. Stanton's studies (unpublished) amounts of the above refined oils on adult include investigations on food shape and color birds. He is determining the degree of de- preferences in wild ducks, the effects of hydration incurred, the resulting pathological lengthened photoperiods on breeding of arctic changes, and the replacement (hormonal and geese, and the effects of diets of varying pro- electrolyte) therapy necessary to rehabilitate tein concentrations on growth and develop- the birds. ment of the common eider duck. As a result of his research on cleaning tech- It is obviously important to keep as many niques and agents, Stanton has recommended birds away from an oil slick as possible. This a nontoxic liquid cleaner called Polycomplex was the objective of an API contract with the A-IL Although not perfect, it is one of several Av-Alarm Corporation of Santa Maria, Cali- cleaning agents being successfully used fornia. Their objective was to determine the today. He has authored a "how to" guide for feasibility of repelling aquatic birds from an oiled-bird treatment entitled "Operation Res- area by using an acoustical jamming device as cue" and prepared a companion bibliography the stimulus. (Stanton 1972). These booklets have been dis- The flocking instinct in birds provides tributed throughout the United States to mutual protection through their almost con- State and Federal agencies and conservation stant communication with one another. When organizations. He has provided consulting this (audio) communication is prevented by services at numerous spills and has worked to jamming with high-frequency sounds, the establish oiled-wildlife treatment centers in birds immediately leave the area to seek relief. coastal States. This harmless technique has been used suc- Since 1972 the API has sponsored an avian cessfully for years to repel agricultural pest physiology study at the University of Cali- birds. 256 K. G. HAY

The Av-Alarm device was tested on water- Committee on Oil Pollution of the Sea estab- fowl at the Grizzly Island Game Refuge some Ushed a research unit in the Department of 48 km north of San Francisco Bay and in the Zoology at the University of Newcastle-Upon- bay itself over a 2-year period (1972-73). Using Tyne. It was funded by a grant from the a single, fixed-location system covering a Royal Society for Prevention of Cruelty to three-quarter square mile (1.21 km^) area Animals, the Royal Society for the Preserva- Crummett (1973) repelled 82% of the ducks tion of Birds, the World Wildlife Fund Sea- and 92% of the shorebirds on the Refuge. The bird Appeal, and the British Institute of intrepid coot, however, was found to be rela- Petroleum. tively indifferent to the sounds. Immediately Their efforts have also led to high survival upon activation, there was a sudden drop in rates. Focusing primarily on the efficiency of the bird count, which was followed by a con- various detergents, they have found that the tinual decline in numbers. loss of waterproofing is largely due to soap In tests of the device from a cruising boat in and oil residues and the disturbance of the ocean and bay waters, the degree of effective- feather structure in the cleaning process. Con- ness varied by species. Ducks were repelled sequently, they have devoted their efforts to 100%; pelicans (Pelecanus spp.) 92%; great selecting detergents that can be completely egrets (Casmerodius albus) 85%; gulls 42%; removed with a minimum disturbance of cormorants 75%; shearwaters (Adamastor plumage (Seabird Research Unit 1971). spp.) 29%; and murres, 51%. In May 1974, the API in cooperation with Grebes and murres dived away from the the U.S. Fish and Wildlife Service convened a stimulus, then surfaced and dived again if the seminar on Oil Spill Wildlife Response Plan- threat was still present. To prevent driving ning. The 2-day workshop was held at the the diving species deeper into the center of a Patuxent Wildlife Research Center at Laurel, slick, investigators recommended that Maryland. Some 70 State and Federal govern- buoyed repelling equipment be placed within ment personnel in charge of oil spill response the spill area. When the alarm system was plans involving wildlife participated. The pro- used in conjunction with the occasional firing gram addressed itself to fish and wildhfe con- of a rocket or shellcracker, an even greater siderations and the role of regional response percentage of birds was repelled. teams under the National Oil and Hazardous The International Bird Rescue Research Substances Pollution Contingency Plan. The Center, a nonprofit corporation in Berkeley, actions of State wildlife departments, U.S. California, was an outgrowth of the Richmond Fish and Wildlife Service, Environmental Bird Care Center that played an active role in Protection Agency, U.S. Coast Guard, and the 1971 San Francisco Bay spill. Since that the oil industry in handling spills involving time, a small group of individuals has con- wildlife were examined. The latest oil spill tinued research on bird-cleaning techniques, cleanup technology was reviewed, and the testing cleaning agents, perfecting husbandry workshop ended with demonstrations of the methods, and alleviating stress. Their 41% cleaning of oiled waterfowl. Similar seminars survival rate speaks for itself. A paper de- were planned for the Gulf of Mexico and the scribing their work is being presented at this West Coast. conference (Smith 1975). It was obvious from this seminar that the Under a grant from the API, the center is most comprehensive wildlife oil spill contin- currently evaluating various cleaning agents, gency plan had been developed by the State of and testing the pressurized jet versus serial California. Copies of this plan (Oil and baths and the re-establishment of feather Hazardous Materials Contingency Plan, Cali- waterproofing. The center is also perfecting fornia Department of Fish and Game, July an audio-visual slide presentation that will 1974) were later distributed to all coastal illustrate how to select the proper cleaning States as a prototype or model plan by API. agent, together with the latest bird-cleaning The U.S. Fish and Wildlife Service has been and care procedures. conducting experiments on various bird-clean- About 5 years ago, England's Advisory ing agents and techniques at its Migratory PETROLEUM INDUSTRY'S ROLE IN MARINE BIRD CONSERVATION 257

Bird and Habitat Research Laboratory near cludes the acquisition of extensive base-line Laurel, Maryland. The Fish and Wildlife Ser- data on all waterfowl, including June surveys vice is also working with the API in develop- of breeding pair counts and August surveys ing information on migratory patterns and for brood counts. The results of these surveys winter waterfowl concentration areas on the for 1969-73 are presented by Gavin (1975). East Coast as they relate to petroleum trans- Base-line data on marine birds of the Gulf of port traffic and oil terminals. Alaska are currently being collected and com- In Canada, the Petroleum Association for piled through grants to various universities Conservation of the Canadian Environment and institutions by the American petroleum (PACCE) employed the services of a consult- industry. These data will constitute elements ing firm to make a comprehensive review of of a report on the environmental status of the dispersal and rehabilitation of waterfowl asso- Gulf of Alaska. Such information is essential ciated with oil spills. The resulting PACCE re- prior to development of the Gulf's offshore port (LGL Ltd. 1974) codified what was petroleum resources. known about the problem, identified research needs, and developed effective wildlife oil-spill Marine Mammals contingency plans for critical areas on coasts, the Great Canada's east and west Most sea mammals are relatively resistant the Arctic. Lakes, and to oil slicks and tend to avoid contaminated The Florida Game and Fresh Water Fish waters. As a result, little research has been Commission has initiated a program for the conducted on cleaning and treatment tech- rehabilitation and treatment of oiled birds. It niques except for experiments on live beavers is being organized by veterinarian Harold F. and on the carcasses and pelts of sea otters Albers of St. Petersburg. He is working in co- and beavers. operation with the Florida Associated Marine No sea otter or seal has ever been oiled and Institutes, the Shell Oil Company, Clean Gulf subsequently cleaned in an oil spill situation. Associates, and the API. It is possible, however, that a spill could have The Standard Oil Company of California significant adverse effects on sea otters and of provided a grant to James Naviaux fur seals, especially at a rookery during the Pleasant Hill, CaUfornia, to develop bird- pupping season. These animals depend on an cleaning technology, including the testing of air blanket trapped in their dense underfur for various cleaners. Dr. Naviaux had treated warmth and buoyancy. Any form of pollutant, spill. birds from the 1971 San Francisco A especially oil, could penetrate the outer guard publication on the after-care of oil-covered hairs and underfur and allow water to reach birds (Naviaux 1972) resulted from the col- the skin, with disastrous effects. laboration with Alan Pittman, research Seals and otters are powerful animals, and chemist of the U.S. Department of Agricul- the larger males and females can be quite ag- ture's Western Research Laboratory. gressive and dangerous. Only professional In 1971, the API in cooperation with the wildlife specialists and consulting veteri- National Wildlife Federation (NWF) initiated narians should be permitted to handle and an NWF/API Fellowship program. One of the treat them. A guide to cleaning and care of first grants under this program was to oiled sea otters can be found in the CaUfornia Charles W. Kirkpatrick, Professor of Wildlife Oil and Hazardous Materials Contingency Management at Purdue University. He and Plan. assistants studied for 4 years the nesting ecology and productivity of the emperor goose Conclusions {Philacte canagica) in the Igiak Bay area of the Yukon Delta in Alaska (Eisenhauer and This status report has revealed that sub- Kirkpatrick 1977). stantial efforts and progress have been made An extensive program of marine bird rein oiled-wildlife research. New techniques search was initiated on the North Slope of being developed are leading to higher survival Alaska by the Atlantic Richfield Company in rates. Preventive measures are being devised 1969. It has been continued ever since and in- to keep birds from entering a spill area. Wild- 268 K. G. HAY

life contingency plans are being developed Fletcher, A. 1973. Why save oiled birds? University and materials to handle future emergencies of California, College of Forestry, Berkeley. 26 pp. (Unpublished report) are being stockpiled. Basic research is being Gavin, A. 1975. Wildlife of the North Slope, a five continued on the difficult problems inherent year study, 1969-73. Atlantic Richfield Co., in achieving high survival levels and a rapid Anchorage, Alaska. 63 pp. return to the wild, at a reasonable cost. Holmes, M. 1973. Oil and p>enguins don't mix. Natl. Much more must be done, but these pioneer- Geogr. Mag. 143(3):384-397. Holmes, W. N., and J. ing efforts both within and outside of indus- Cronshaw. 1975. Final progress report on studies completed, 1972-75, on the try reflect a difficult problem yielding to the effects of petroleum on marine birds. American attention of time and dedicated men and Petroleum Institute, Washington, D. C. 77 pp. women. (Unpublished report) LGL Limited. 1974. Review of current knowledge on reducing bird mortalities associated with oil spills. Petroleum Association for Conservation of References the Canadian Environment Rep. 75-4. 50 pp. Lassen, R. W. 1972. Waterbirds and the San Fran- Atkinson-Willes, C. 1963. Wildfowl in Great cisco oil spill. Proc. Cal-Nev Wildl. 1972:20-24. Britain. Nat. Conserv. Monogr. 3. 368 pp. Naviaux, J. L. 1972. Aftercare of oil covered birds. Advisory Committee on Oil Pollution of the Sea. National Wildlife Health Foundation, Pleasant 1972. Research unit on the rehabilitation of oiled Hill, Calif. 52 pp. seabirds. Committee, Dep. Zool., Univ. of New- Ottway, S. M. 1971. A review of world oil spillages, castle-Upon-Tyne, England, Annu. Rep. 2. 33 pp. 1960-1971. Oil Pollut. Res. Unit, Orielton Field Bergman, G. 1961. The migrating populations of Centre, Pembroke, Wales. the longtailed duck (Clangula hyemalis) and the Parslow, J. L. F. 1967. Changes in status among common scoter (Melanitta nigra) in the spring, breeding birds in Britain and Ireland. Br. Birds 1960. Suomen Riista 14:69-74. 60:2-47,97-122,177-202. Blanks, D. W. 1942. Birds in the war zone. Gull Rowan, M. K. 1968. Oiling of marine birds in South 24(4):11. Africa. Pages 121-124 in Proc. Int. Conf. on Oil Bourne, W. R. P. 1970. Special review—after the Pollut. of the Sea. Torrey Canyon disaster. Ibis 11 2(1): 124. Seabird Research Unit. 1972. Advisory Committee on Oil Pollution of the Sea Research Unit on the Clark, R. B. 1969. Oil pollution and the conserva- Rehabilitation of Oiled Seabirds. Second annual tion of seabirds. Proc. Int. Conf. on Oil PoUut. of report. Dep. Zool., Univ. of Newcastle-Upon- the Sea 1968:76-112. Tyne, England. 33 pp. Clark, R. B. 1973. Impact of chronic and acute oil Small, John. 1971. The oil spill in retrospect. Point pollution of seabirds. Page 634 in Background Reyes Bird Observatory News 18:1-2. papers for a workshop on inputs, fates and effects Smith, D. C. 1975. Rehabilitating oiled aquatic of petroleum in the marine environment. Vol. 11. birds. Pages 241-247 in Proc. 1975 Conf. Preven- Ocean Board National Academy of Science, tion and Control of Oil Pollution. Washington, D. C. Smithsonian Institution. 1971. Annual report of Crummett, J. G. 1973. Bird dispersal techniques for the Center for Short-lived Phenomena, 1970. use in oil spills. Final report. American Petroleum Cambridge, Massachusetts. Institute, Washington, D. C. Stanton, P. B. 1972. Operation rescue. American Edwards, R. A. 1963. Treatment of washed up pen- Petroleum Institute, Washington, D. C. 32 pp. guins. Bokmakierie 15(1):8. Tanis, J. J. C, and M. F. Morzer-Bruyns. 1968. The Eisenhauer, D. I., and C. M. Kirkpatrick. 1977. impact of oil-pollution on seabirds in Europe. Ecology of the emperor goose in Alaska. Wildl. Proc. Int. Conf. on Oil Pollut. of the Sea. 1968:67- Monogr. 57. 62 pp. 76. CONSERVATION OF MARINE BIRDS IN OTHER LANDS

~~Conservation of Marine Birds in New Zealand~~

~~Gordon R. Williams New Zealand Wildlife Service Department of Internal Affairs Wellington, New Zealand~~

~~Abstract~~

Marine species (pelagic birds and those of exposed coasts) make up about 48% of New Zealand's native avifauna, excluding stragglers and antarctic species. The biological history that has led to the present status of marine birds in this archipelago of some 700 islands is outlined, methods of conservation are briefly described, and some illustrative case histories of management programs are given. In spite of the major environmental changes that have occurred in New Zealand during 200 years of European occupation, only one marine species has become extinct, although five such endemic species are currently regarded as threatened as are a few subspecies of widely distributed forms.

New Zealand, which lies some 2,000 km about 48% of the 173 in the New Zealand southeast of Australia, has been a changing Checkhst (Kinsky 1970). Of the 83 species I archipelago for many millions of years. It has have regarded as marine, 48 (28%) are pelagic been separated from any major landmass and 35 (20%) shorebirds of exposed coasts. (first, Gondwanaland and later, Australia) for Ten of the 48 pelagics (21%) and 12 (34%) of at least 80 million years. the 35 shorebirds are endemic. Before the arrival of man, probably between More than a thousand years of occupation 1,000 and 1,500 years ago, New Zealand was by Polynesian man with his commensal Poly- free of any land mammals except two species nesian rats (Rattus exulans) and a peculiar of bats, and there were few avian predators. breed of domesticated and feral dog (now ex- These, among a number of other biological tinct), did little damage to pelagic and open peculiarities, reflect the archipelago's con- coast species, even though many, if not most, siderable and long-standing isolation. were used as food— especially the petrels, and There are nearly 700 islands 0.5 ha or more particularly those belonging to the genera in area in the New Zealand region; and, if Puffinus, Procellaria, and Pterodroma. How- North, South, and Stewart islands are re- ever, the Europeans, who arrived about 200 garded collectively as the mainland, about years ago, brought with them a menagerie of 650 of these islands Ue within 50 km of the mammals and birds, and 33 species of each coast and 30 beyond that limit, to about have become established and are now feral 850 km offshore (Atkinson and Bell 1973). (Gibb and Flux 1973; Williams 1973). They The archipelago extends from about 30° to also put into practice, on a large scale, Euro- 52 °S lat. (over a distance of about 2,400 km)— pean methods of land use that had unfortu- that is, from the subtropical to the sub- nate effects on almost the entire native avi- Antarctic—and from about 166° to 176°W fauna. Although terrestrial, freshwater, and long. (Fig. 1). estuarine species suffered most, marine Pelagic and coastal birds must obviously be species suffered also. However, reduction in an important part of the avifauna and, in fact, numbers and range rather than extinction aside from stragglers, antarctic species, and was the rule, except locally. established introduced species, they make up Apart from habitat destruction by man and

~~261 262 G. R. WILLIAMS~~

from the recognition of the value of certain islands as refuges for whole ecosystems, as convenient areas for study, and as arks for the rescue of the threatened species that can be successfully established on them—an often highly hazardous and uncomfortable procedure for men as well as birds.

~~Conservation Measures~~

By statute, all feral species of birds in New Zealand are automatically protected unless specifically legislated for otherwise. (About 50 of our grand total of 285 species have been so legislated for.) One fortunate consequence of this provision is that all new arrivals— vagrants or new discoveries—are also fully protected. The legislation also states that it is illegal to have in one's possession the nests, eggs, feathers, skins, or bones of any fully protected species unless one has been issued a permit for this purpose. This restriction may apply to institutions as well as to persons. After this good start and the setting aside of conservation reserves of various kinds, ac- Fig. 1. New Zealand and its main offshore and out- tive conservation measures depend on making lying islands (from Atkinson and Bell 1973). careful and comprehensive surveys of the species and its ecosystem—often none too easy a task in the New Zealand region because the various mammalian browsers and grazers, of the rough seas, the relative inaccessibility the most inimical agents have been black rats of many of the important islands and their

{Rattus rattus), Norway rats (/?. norvegicus), ruggedness, and the near-impenetrability of feral cats, and feral pigs. One would expect some of the vegetation types they support. the inhospitality or inaccessibility of an island Having decided that positive action is neces- to be a marine species' best protection, and so sary, the next step is to use all available it has generally proved— the greatest losses media to inform the public (local as well as na- have occurred on the two major mainland is- tional, if the island is inhabited) of the situa- lands (North Island and South Island). tion and the proposals for remedying it. As in Bourne (1967) suggested that Polynesians in most other countries, uninformed emotional- pre-European times may have caused the ex- ism is one of the most pervasive and serious tinction of numerous petrels in the Chatham obstacles to effective conservation because of Islands. There are still a few islands on which the political pressure it can generate. no exotic mammals occur, but modern trans- Apart from formal ecological studies, the port, allied with human curiosity and New Zealand WildUfe Service uses three main cupidity, are stripping all but the most wild methods to support threatened species (other and remote of these of the protection against than the attempts we are making to breed cer- invasion they have had so far. Cruises by tain freshwater and terrestrial species in nature-hungry but sometimes environ- captivity): mentally ilUterate tourists are beginning to be • The translocation and founding of new a local problem. colonies in promising or unmodified habitat. The matter of conservation of marine Such habitats are not common in New Zea- species in New Zealand has stemmed mainly land because of the ubiquity of the introduced CONSERVATION OF MARINE BIRDS IN NEW ZEALAND 263 mammalian browsers, grazers, and predators Some Case Histories (WilUams 1977). • The destruction, or at least the reduction, Translocation of such browsers, grazers, and predators by Last century, an endemic monotypic genus physical, chemical, or biological methods, or of wader— the New Zealand shore plover (Thi- combinations of these. nornis novaeseelandiae)—was widespread and • The exertion of social influences to pro- occasionally very common around the coasts mote changes in methods of land use or in tra- of the North and South islands and the Cha- ditional harvest for food (the latter can be par- tham Islands. As a result of European settle- ticularly important as far as the Polynesian ment and the accompanying predation by [Maori] population is concerned, as nowadays feral cats and rats, the species now occurs the taking of birds for food is predominantly a only on South East Island in the Chatham cultural rather than an economic matter). group (860 km east of the mainland), where it Translocation has been a valuable technique at present seems safe, since there are no rats for increasing the numbers and ranges of a on the island and it is now a reserve. However, few threatened terrestrial species. The very the population numbers only about 120 indi- nature of most marine species, however, viduals. Because calamities can always occur limits its application as far as they are con- (for example, ship rats recently reached shore cerned. Nevertheless, we have considered it on three important islets off the southwest worth trying for one nonmigrant wader; and coast of Stewart Island), the Wildlife Service no doubt it could be tried under similar cir- is anxious to spread the shore plover to other

cumstances elsewhere. suitable islands, if they can be found. The Convincing local experiences have shown species is not a migrant and is rather seden- that predator or competitor destruction is tary. The first translocation attempts failed, likely to be practical only on small, not-too- probably because mainly adult birds were rugged islands, usually no larger than about used, and we are now continuing our studies 500 ha. However, special circumstances have of the species with the thought in mind, prompted us to attempt destruction, or at among others, that success may come if least control, on much larger and more diffi- young birds are used instead; the question cult islands. It is implicit that the predators is—how young? or competitors are exotic, not indigenous. Re- As is widely known, the New Zealand Wild- cently, on those rare islands that are in- life Service has been remarkably successful in habited but still free of either black or Norway recent years in translocating one species of rats, we have set up permanent bait stations the endemic wattlebird family— the forest- (at which sodium fluoracetate— "1080"— is dwelling saddleback (Philesturnus caruncu- used as the poison) on wharves and jetties in latus)— to other islands than the four small the hope that such a precaution will, with the ones it had been reduced to by the early addition of a propaganda campaign calling for 1960's; three of these islands were the ones re- the regular fumigation of visiting vessels, pro- cently invaded by ship rats, referred to above. long the charmed lives that these fortunate islands have so far enjoyed. It goes without Predator Control saying that we ask that the greatest care be Some 25 km off the North Island's east taken when expeditions land stores on unin- coast lies the 3,000-ha, very rugged and habited, rat-free islands which, if by "rat- forested Little Barrier Island, which has now free" we mean also free of i?. exulans, are even been a reserve for the protection of flora and rarer in our seas. fauna for about 80 years. Before that, it had The sociolegal approach is effective only been almost continually occupied by Maoris when ecosystems or communities have not since their arrival in New Zealand, and about been seriously modified, otherwise it is no one-third of its forest was felled or burnt, es- substitute for either of the other two meas- pecially after European settlement of the ad- ures discussed. joining New Zealand mainland began. 264 G. R. WILLIAMS

Most unusually, Little Barrier is now free of tropic and sub-tropical marine avifauna. Un- any grazing or browsing mammals, and has fortunately, goats were liberated on the two only the Polynesian rat (a reminder of the largest islands— Raoul (3,000 ha) and Maori occupation) and feral cats (a European Macauley (300 ha)—almost 150 years ago and legacy) to impair its extreme importance as a Macauley Island was burnt over; such forest reserve. The rats have been unmolested by cover as it had was severely damaged or de- man because, rightly or wrongly, they are con- stroyed, probably at about the same time. The sidered ineffective predators generally; how- goats were to be an emergency food supply for ever, their impact has probably been under- whalers and shipwrecked mariners. Cats, too, rated. More than half a century of trapping became feral on Raoul Island during one of its and hunting of cats by successive caretakers fitful periods of occupation. The New Zealand on the island has not effectively reduced that Wildlife Service, in spite of the distance and population. difficulties involved, has undertaken pest de-

Among its other important attributes. struction campaigns on both islands, but I Little Barrier supports two birds endemic to offer here only an account of the simpler, and New Zealand— the rare black petrel (Procel- more successful, Macauley operation. laria parkinsoni), and one endemic honey- In 1966, a 5-week expedition to this water- eater, the stitchbird (Notiomystis cincta), less and almost treeless island resulted in the which was once widespread on the North Is- shooting of what was then thought to be all of land but is now found only on Little Barrier in its 3,000-odd goats (a density of about 15/ha). moderate numbers, and apparently in no im- Four years later, a follow-up expedition found mediate danger. The impact of feral cats on and destroyed another 17 goats (a later brief stitchbirds has not been determined, but it is inspection suggested that these were indeed known that cats are seriously affecting the the last), and rehabilitation of the island is black petrel especially: they kill at least 90% well under way. Now that the short turf is dis- of the chicks and some adults annually. Their appearing, erosion of the soft volcanic soils is impact on a locally remnant population of reduced. With compaction no longer occur- Cook's petrels (P. cookii) is apparently less ring, it will be interesting to see what the ef- severe. fect will be on birds breeding on the island- In 1968-69 the Wildlife Service, with veteri- six breeding species of petrels, three breeding nary advice and assistance, added an attempt species of terns, and other marine species. at biological control to the campaign of poisoning ("1080" in fish was the poison and bait Sociolegal Conservation used), trapping, and shooting. The very The taking of petrels and other procellarii- specific viral disease— feline enteritis—was inform birds for food has always been part of troduced by trapping island cats, infecting the Polynesian economy and culture through- them, and then releasing them. Some esti- out the Pacific. In New Zealand, the practice mates of the resulting mortality from the now has only minor economic importance, but combined techniques were as high as 90%; but it is still an essential part of Maori culture and there has been a recovery since, and the cam- tradition. The most commonly taken species paign is expensive in both time and man- are the sooty shearwater (Puffinus griseus) power. And, oddly enough, the control effort and, until recently, the gray-faced petrel has met with some opposition. Nevertheless, (Pterodroma macroptera). Although no formal another campaign is planned. study of the impact of the annual harvest of chicks on the population has yet been made, Habitat Rehabilitation by all the indications are that it is not signifi- Destruction of Mammals cant. Nevertheless, the Maoris willingly ac- The Kermadecs are a group of small islands cepted the limited amount of legislation that about 800 km north-northeast of the North has been passed to afford the two principal ex- Island. Their biological significance, insofar ploited species at least token protection. How- as this symposium is concerned, is that they ever, on the Chatham Islands, where there is a are the southernmost breeding area in New strong tradition of taking some of the alba- Zealand seas for many elements of the Pacific trosses, this tradition has persisted, even CONSERVATION OF MARINE BIRDS IN NEW ZEALAND 265

though all albatrosses are fully protected chathamensis). However, a list of this kind is throughout New Zealand. often a matter of some controversy. Some- Enforcement of legislation in small and iso- thing is at present being done to help all but lated communities is not always easy and the first and last of these. The Chatham Is- sometimes may not be wholly politic. How- land taiko had not been positively identified ever, the Maoris of the Chathams have been for about 50 years, until 1977 when this specially informed of the conservation issues species was "rediscovered" on the main island at stake, and a "gentleman's agreement" has of the Chatham group; though its numerical been reached: If a planned survey shows that status is unknown, it is rare. The Chatham Is- full protection of albatrosses in the Chathams land oystercatcher, although certainly is indeed essential, the Maoris will honor the "threatened" (only about 50 are known to legislation to the letter; on the other hand, if exist), does occur on four islands, two of which limited exploitation seems justified, the Wild- are reserves. Although this species has not life Service has agreed that it will be allowed. been actively studied until now, it is soon to be the subject of a full ecological survey.

A few words about the hunting of marine Conclusions species: Muttonbirding aside— that is, apart from the taking by Maoris of the young of the Insofar conservation measures of a pas- as sooty shearwater and the gray-faced petrel- sive type are concerned, it is fortunate that there has been no legal hunting of any marine the offshore and outlying islands not yet occu- birds in New Zealand for 35 years now, nor is pied, farmed, or set aside as reserves, are there likely to be. This situation reflects the likely remain unexploited, either because to consistently increasing weight of informed they are too remote for exploitation to be eco- public opinion in favor of, let alone scientific nomical or because they are too inhospitable, concern for, transoceanic migrants. The pro- or both. In any event, public opinion is now hunting lobby for some species of waders, in that unmodified or otherwise biologi- such particular the eastern bar-tailed godwit cally important islands not already reserved (Limosa lapponica baueri), is a small one, the be proclaimed as reserves if threat of would numbers of which decrease yearly. However, exploitation arose unexpectedly, unless they small-scale poaching occasionally occurs; it is to major sites for oil or were found be punished when discovered. minerals. Even so, legislation exists that Protection for marine species extends only offers the possibility of protection even from to the 3-mile limit of New Zealand's territorial this threat, and has already been used to it would be extended further exempt some important mainland areas from waters, but Zealand follow the present trend prospecting and the granting of mining should New including as territorial waters all those that rights. of cover the continental shelf or beyond. [This It is gratifying to realize that, although extension occurred in 1977; the marine fishing some endemic marine subspecies (generally zone for Zealand waters has been ex- not very different from neighboring sub- New tended to 200 miles (360 km) around all species) are endangered to varying degrees, coasts.] there are very few whose disappearance would result in the disappearance of the species it- Only three marine species are not afforded self from the New Zealand area. Only one en- full protection under the Wildlife Act: Two, demic marine species has become extinct in re- the black-backed or Dominican gull (Larus cent times, the Auckland Island merganser dominicanus) and the black shag (Phalacro- (Mergus australis) in about 1905, and only six corax carbo), are totally unprotected— the are currently in any real danger: the Chatham first because of its predation on some rare Island taiko {Pterodroma magentae), the shorebirds during the breeding season and for black petrel, Hutton's shearwater (Puffinus its attacks on sheep and lambs at a similar huttoni); the Westland black petrel (Procel- time, and the second because of its depreda- laria westlandica), the shore plover, and the tions (seldom serious) on the introduced trout Chatham Island oystercatcher (Haematopus and salmon, mainly in fresh waters—the third G. R. WILLIAMS

species, the southern skua (Stercorarius skua Acknowledgments lonnbergi), may be destroyed only when it is actually attacking sheep or lambs, an occa- I thank my WildUfe Service colleagues, sional event confined to the Chatham Islands. B. D. Bell, M. J. Imber, D. V. Merton, and Destruction of these three common species is C. J. R. Robertson, for valuable comments not encouraged by the Wildlife Service except and advice on the preparation of this paper. when black-backed gulls become too active among colonies of, say, the fairy tern (Sterna nereis), which is very rare in New Zealand but not elsewhere in its range. Otherwise, control of the species is left in the hands of those most References affected by their depredations but whose judgment is usually reasonable. Atkinson, I. A. E., and B. D. Bell. 1973. Offshore Marine birds, therefore, are generally satis- and outlying islands. Pages 372-392 in G. R. Williams, ed. The natural history of New Zealand. factorily protected by law or managed for con- A. H. & A. W. Reed, Wellington. servation in New Zealand— especially when Bourne, W. R. P. 1967. Subfossil petrel bones from one considers the remarkable changes that the Chatham Islands. Ibis 109:1-7. have occurred in the New Zealand archipelago Kinsky, F. C. 1970. Annotated checklist of the birds over the last 200 years. Although the situa- of New Zealand. A. H. & A. W. Reed, Wellington. Gibb, J. A., and J. E. C. Flux. 1973. Mammals. tion could be better, it would certainly have Pages 334-371 in G. R. Williams, ed. The natural if Service (and other been worse the Wildlife history of New Zealand. A. H. & A. W. Reed, conservation organizations) had not been un- Wellington. tiring in keeping the general public and the Williams, G. R. 1973. Birds. Pages 304-333 in G. R. natural history of Zealand. legislature aware of the issues at stake and Williams, ed. The New A. H. & A. W. Reed, Wellington. seen to it that as much as possible of the nec- Williams, G. R. 1977. Marooning— a technique for essary conservation work was done—and saving threatened species from extinction. Int. done before it was too late. Zoo Yearb. 17:102-106. Marine Birds in the Danish Monarchy and Their Conservation

~~Finn Salomonsen~~

~~Chief Curator of Birds The Zoological Museum University of Copenhagen Copenhagen, Denmark~~

~~Abstract~~

Most species of seabirds that regularly breed in Denmark are declining, for a variety of reasons: shooting; oil pollution; toxic chemicals; reclamation of land; collecting of eggs; disturbance at breeding sites by visitors, motorboats, camping, etc.; destruction by predators; and others. On the other hand, the numbers of certain other species are increasing as a result of climatic changes (six species), protection (three species), and increase in food supply (three species of gulls). In addition to breeding birds, a total of about 3 million birds occur in Danish waters as passage migrants or winter visitors. More than half of the European winter populations of a number of marine waterfowl species winter in Denmark. Large numbers of seabirds spend the summer in Danish waters, including several hundred thousand immature gulls and just as many molting waterfowl. The seabird fauna of the Faroe Islands is very rich, the immense number of birds being attracted by the local abundance of macroplankton and fish. The seabirds are harvested by man, formerly by fowling (capturing and shooting), now primarily by shooting. Until about 1910, more than 400,000 birds were taken annually by fowling. The Faroese game act is now very restrictive, and most seabird populations appear to be almost stable. However, a census in 1972 indicated that common murres {Una aalge) have declined by about 20% to a population of about 600,000. Shooting and snaring appear to be the primary causes of the decline; oil pollution and toxic chemicals do not seem to be contributing to the population decrease. In Greenland seabirds provide an important source of human food; however, because of the increase in human population and in the use of guns and speedboats for hunting, and the absence of a game act, serious overshooting of seabirds is taking place. A new game act passed in 1977 should largely alleviate this overharvest. Oil pollution and toxic chemicals do not yet play an important part in influencing the number of seabirds, though offshore oil drilling is being initiated in West Greenland. A recently established gigantic national park, covering 200,000 km^ of ice-free land, is the largest nature reserve in the world.

~~267 268 F. SALOMONSEN~~

The Danish Monarchy consists of three Seabirds regularly breeding in Denmark in- parts far removed from each other, scattered clude five species of terns (common tern. in the North Atlantic—namely Denmark Sterna hirundo; arctic tern, S. paradisaea; proper, the Faroe Islands, and Greenland. least tern, S. albifrons; Sandwich tern, They differ so much from each other in cli- S. sandvicensis; and gull-billed tern, Gelo- mate and in bird life that they must be treated chelidon nilota); seven species of gulls (black- separately in this paper. The Faroes possess a headed gull, Larus ridibundus; herring gull, provincial government and also a sort of home L. argentatus; lesser black-backed gull, L. fus- rule. Greenland also has a provincial govern- cus; great black-backed gull, L. marinus; mew ment, but all statutory provisions, including gull, L. canus; Uttle gull, L. minutus; and acts concerning hunting or wildlife protection, black-legged kittiwake, Rissa tridactyla); four must be passed by Danish authorities, usually species of geese, swans, and ducks (mute by the Ministry of Greenland. swan, Cygnus olor; greylag goose, Anser Insofar as seabirds are concerned, it is im- anser; common eider, Somateria mollissima; portant that Greenland is an arctic country, common merganser, Mergus merganser; and whereas the Faroes and Denmark are boreal. red-breasted merganser, M. serrator); three In both Greenland and the Faroes the breed- species of auks (black guillemot, Cepphus ing birds are most significant, from an eco- grylle; common murre, Uria aalge; and razor- logical point of view, whereas in Denmark the bill, Alca tarda); and one species of cormorant passage migrants and winter visitors are far (great cormorant, Phalacrocorax carbo). more important. Shorebirds have not been included in this re- There are other differences as well. In view. Some of the species mentioned are Greenland and the Faroes the seabirds mostly partly freshwater birds— for example, the breed in colonies on high and steep cliffs, and black-headed gull, little gull, mute swan, grey- the structure of these breeding places is not lag goose, and the two species of mergansers. disturbed .by man. In Denmark, on the other The gull-billed tern forages in terrestrial habi- hand, the seabirds usually breed on glacial de- tats, but nests along the coast with the other posits, now forming meadows, low islets, salt seabirds. It is often difficult, therefore, to marshes, etc., and these habitats have unfor- make a clear-cut distinction between seabirds tunately been largely changed in the last hun- and freshwater birds. dred years by draining and reclamation. This Among the auks, the black guillemot practice has taken place in Denmark on a breeds in the Cattegat area in the huge heaps much larger scale than in most other coun- of boulders on small raised islets, or in holes tries and has, therefore, to a high degree (mostly formed by starlings, Sturnus vul- diminished the life conditions of seabirds. garis) on steep clayey slopes or promontories. The common murre and razorbill are restricted to the islet Graesholm in the Chris- Seabirds in Denmark tians Archipelago, about 24 km east of Born- holm Island in the Baltic, where they breed on Denmark is situated on the continental small cliffs of Precambrian granite rock. shelf of western Europe; all seas surrounding The estimated number of seabirds of dif- the country are shallow (less than 100 m ferent species that breed in Denmark is shown deep), apart from the Skagerrak, north of Jut- in Table 1. Species like the mergansers, mute land, which is much deeper. The shallow swan, and greylag goose, which breed partly depth, combined with the rapid flow of water or mostly in freshwater localities, are not in- between the Baltic and the North seas causes cluded. Overall, the number of breeding sea- much upwelling, which forms excellent life birds is slowly declining, probably due to conditions for plants and animals. It is well many factors which are discussed below. known that the fishery in Danish waters, es- There are two exceptions, however, to this pecially in the North Sea, is very rich. This general decrease— the herring gull (and to a richness of the seas provides suitable condi- lesser degree the other big gull species) and tions for a high diversity of seabirds and eco- common eider. Both species have increased logical types. during the last 50 years. Since they breed in )

~~CONSERVATION OF MARINE BIRDS IN THE DANISH MONARCHY 269~~

Table 1. Estimated average number of breed- breeding population of herring gulls at ing pairs of seabirds in Denmark, based on a Hirsholmene and Christians* sanctuaries (in census in 1970-72. (Data for terns from 1973 and 1974, respectively), to improve con- Mardal 1974, and for other species from ditions for other nesting seabirds. In 1969 the Sten Asbirk and N. O. Preuss, personal Bird Strike Committee of the Royal Danish

communications . Airforce also initiated a program to reduce the number of herring gulls breeding on Number of Saltholm Island, which is near the Kastrup breeding airport in Copenhagen. Nests were sprayed Species pairs with a formaldehyde oil dye, which resulted in Sterna paradisaea 5,750 a 33% reduction in population. In Christians* S. hirundo 900 and Hirsholmene, where the adult breeding S. sandvicensis 4,000 birds were poisoned, the effect is not yet S. albifrons 600 known. Gelochelidon nilotica 105 The total number of seabirds occurring in Larus marinus 300 the L. argentatus 60.000 Danish waters as passage migrants and L. fuscus 2,000 winter visitors is substantially larger than the L. canus 28,500 breeding population, because Denmark is L. ridibundus 135,000 situated on a very important fall migration L. minutus 25 route for seabirds from Scandinavia, the Bal- Rissa tridactyla 125 tic countries, northern Russia, and northwest- carbo Phalacrocorax 600 ern Siberia. Furthermore, the shallow waters Somateria mollissima 3,800 of the Danish seas (less than 10 m deep) that Cepphus grylle 325 occupy extensive regions bordering the coasts Alca tarda 400 are important feeding grounds for diving Uria aalge 1,100 Total 243,530 ducks. Birds frequenting the seas outside the breeding season include hundreds of thousands, or probably millions, of gulls; numerous ducks (especially diving ducks); the same habitat, usually mixed together, the swans and brants, Branta bernicla; jaegers, eider is probably dependent on herring gulls Stercorarius spp. (four species); loons, Gavia for protection against predators. When the spp. (four species); grebes, Podiceps spp. (four ducklings are fledged, the herring gull acts as or five species); gannet, Moras bassanus; a successful predator itself, but the eider great cormorant; northern fulmar, Fulmarus nevertheless maintains a close association glacialis; common murre; razorbill; and other with herring gulls. species of alcids. To these should be added a More than 90% of the herring gull popula- number of species of various seabirds, espe- tion breeds on small islands, and a large pro- cially gulls, tubenoses, phalaropes, and others portion occurs in a few large colonies. It never which appear as casual or accidental visitors breeds in freshwater localities, but is exclu- and which are not further mentioned in this sively found as a breeding bird in coastal habi- paper. tats. The population has particularly in- A comprehensive investigation of the non- creased in the last 5 decades, some colonies breeding waterfowl in Danish waters was re- reaching their maximum size in the 1960's. cently undertaken by the Game Biology Sta- Others are still expanding and occupying new tion Kal* (Joensen 1974). Aerial surveys of breeding grounds. Today the largest colonies marine ducks indicate that a large percentage are found on the following islands: Saltholm, of the ducks that winter in European waters 20,000-40,000 pairs; Christians* 9,000 pairs; do so in the shallow areas of the Danish seas. Hirsholmene, 2,500 pairs; Jordsand, 1,800 A census in January 1973 indicated a total of pairs; Sams

Table 2. Total numbers of ducks, swans, and coots recorded in Denmark during a winter census in January 1973 (based on ground counts and aerial surveys), compared with estimated flyway populations wintering in western Europe and annual bird harvest in Denmark (after Joensen 1974:23, 155, 168).

~~Estimated winter Average Census, populations of the annual bag Species January 1973 Western Europe Flyway in Denmark~~

Anas platyrhynchos 127,000 1,550,000 380.000 A. crecca 500 260,000 76,000 A. querquedula 11 a b A. acuta 100 70,000 13,000 A. strepera 5 a c A. penelope 3,000 485,000 44,000 A. clypeata 17 63.000 9,000 Tadorna tadorna 13,000 105,000 c Aythya ferina 7,100 235,000 5,000 A. fuligula 94,700 530,000 35,000 A. marila 80,900 145.000 8,000 Clangula hyemalis 11,000 a 11,000 Melanitta nigra 148,100 a 18,000 M. fusca 6,700 a 9.000 Somateria mollissima 450,800 a 136,000 Bucephala clangula 67,000 142.000 25,000 Mergus serrator 11,700 40.000 8.000 M. merganser 23,200 75.000 6,000 M. albellus 206 5.000 c Cygnus olor 48,900 120,000 c C. cygnus 5,700 17,000 c C. bewickii 1,113 6,000 c Fulica atra 142,500 a 70.000 Totals 1,243,252 3,848,000 853.000

~~^Not counted. ''No estimate, but number insignificant.~~

~~•^ Species totally protected.~~

censuses usually give minimum numbers, and Europe; about one-third of the population of certain species—especially marine ducks— tufted duck (Aythya fuligula) and common generally go unrecorded, the normal winter merganser; and probably also one-third of the population (November to February) of ducks, population of common eider and coot (Fulica swans, and coots in Danish waters can atra). scarcely be less than 2 million birds (Joensen The wintering population of common eider 1974:156). In Table 2, bird numbers in Den- is very large. According to banding records it mark are compared with the estimated winter makes up the greater part of Baltic breeding populations in western Europe, based on the birds; however, it is not possible to calculate investigation of Atkinson-Willes (1972). its percentage contribution to the total Euro- When all the winter censuses in Denmark are pean winter population since its size is un- compared with those for Europe, as was done known in most European countries. Although by Joensen (1974:156), it is evident that most of the surface-feeding ducks disappear Danish waters support about half of all from Denmark waters in winter, extremely greater scaup (Aythya marila), common large numbers occur there during the fall mi- goldeneye (Bucephala clangula), red-breasted gration period. For example, it has been esti- merganser, mute, whooper (Cygnus cygnus), mated that for species Uke common teal (Anas and tundra swans (C. bewickii) wintering in crecca) and wigeon (A. penelope) about one- CONSERVATION OF MARINE BIRDS IN THE DANISH MONARCHY 271

third of the West European Flyway popula- ceps nigricollis (about 1870); red-crested tion passes Denmark in the fall. Possibly pochard, Netta rufina (1940); common some of the surface-feeding ducks listed in pochard, Aythya ferina (about 1860); tufted Table 2 for January 1973 were recorded in duck (about 1900); and common murre (1929). fresh water and not from the seas, but at the They all still breed in Denmark, having more time the census was taken most freshwater or less increased in number. lakes were frozen and, therefore, unavailable Another reason for increases of certain for water birds. species is legal protection. Among protected These breeding seabirds and the off-season seabirds are the sheld-duck, which has been visitors do not constitute the total population completely protected since 1931, and particu- in Danish waters. Large numbers also occur in larly the mute swan, of which only 2 or 3 pairs summer as nonbreeding birds; most are in two were breeding in Denmark when the species categories: (1) several hundred thousand pre- was completely protected in 1926. Since then, adult (up to 4-5 years of age) gulls (mostly mute swans have increased enormously, great black-backed, herring, and lesser black- reaching at least 2,740 pairs in 1966 (Bloch backed gulls), which feed inshore or at the 1971:43), of which large numbers were breed- coast, and (2) large concentrations of water- ing colonially on small islets of boulders or on fowl that carry out a molt migration in sand reefs off the coast (Bloch 1970:152). The Danish waters, particularly in shallow areas. gannet has also increased considerably as a Black scoter {Melanitta nigra), velvet scoter fall visitor since about 1945, apparently due (M. fusca), common eider, and whooper swan to protection in England and other countries. are especially numerous, totaling hundreds of Finally, some gull populations have in- thousands of individuals, and probably con- creased in size because of an increase in the stituting the majority of the European molt- food supply, consisting especially of wastes ing populations of these species. Less from commercial fisheries and garbage numerous, but still totaling thousands of dumps. In Denmark, this unnatural food molting birds, are sheld-duck {Tadorna source has caused an enormous increase since tadorna), common goldeneye, red-breasted about 1925 in herring gulls (from less than merganser, and possibly some other diving 500 pairs to 60,000 pairs), lesser black-backed ducks. About 3,000 surface-feeding ducks of gulls (all three subspecies, fuscus, inter- various species, most of which undoubtedly medius, and graelsii have immigrated to Den- are local breeding birds undergo wing molt in mark), and great black-backed gulls (immi- Danish waters. Comprehensive descriptions grated to Denmark in 1930). Improved waste of the molt migration, particularly in Den- disposal practices in recent years have not yet mark, were published by Salomonsen (1968) offset the rate of growth of these gull popula- and Joensen (1973a, 1974). tions. The increase of common eiders, which It may then be concluded that very large also started in about 1925, is probably related numbers of seabirds are found in Danish to the increases in the larger gulls. waters in all periods of the year; most feed in the inshore zone and some offshore, but none Decrease of Seabirds in the pelagic zone.

A variety of factors tend to reduce the numbers of seabirds. The most important ones are Increase of Seabirds outlined below, with comments on what has been done or what is expected to be done to re- Seabirds are affected by several factors reduce the impact of these activities on seabirds lated to human activities, most of which pose and protect this endangered resource. a threat to them and will eventually reduce their numbers. Some factors, however, tend to Shooting of Seabirds increase bird numbers, like climatic changes which, as reported by Salomonsen (1963), have The shooting of seabirds in Denmark is con- given rise to the immigration to Denmark of siderable, because the seabirds are extraordi- great cormorant (in 1938); eared grebe, Podi- narily numerous, and the number of sports- 272 F. SALOMONSEN

men is very large, amounting to about Table 3. Open hunting seasons for seabirds 135,000 (a larger number per capita than in in Denmark, according to the Game Act any other country). of 1967. Species not given in the table are The Danish game statistics are excellent- fully protected. well known to be much more accurate than in Hunting period and species most other countries (see Salomonsen 1954; Strandgaard 1964). According to Danish bag 1 August-31 December records, almost one million ducks, geese, and Anseranser coots (Joensen 1974:31) and about 100,000- A. fabalis A. brachyrhynchus 200,000 gulls (Salomonsen 1954:125) are shot A. albifrons each year. The average annual bag of each Branta bernicla^ species of wildfowl is given in Table 2 and the B. canadensis open season for each species of seabirds in 1 August-30 April Table 3. The open season for dabbling ducks Phalacrocorax carbo is long, extending from 16 August to 31 De- 16 August-31 December cember, which means that local birds are per- Anas platyrhynchos secuted almost as soon as birds-of-the-year A. crecca are able to fly. This has resulted in a dabbling A. querquedula duck breeding population that is much A. acuta penelope smaller than what the available food supply A. A. clypeata could support, and in the large-scale develop- 16 August-29 February ment of artificial rearing of mallards for later Aythya ferina shooting. 5-month hunting season on A Fulica atra specialized birds like loons, grebes, and Lams ridibundus various auks is not good management prac- L. canus tice and should be carefully reviewed. 16 August-30 April Four other important facts about the shoot- L. fuscus L. argentatus ing of seabirds in Denmark merit inclusion L. marinus here: (1) there is no bag-limit for any species; 1 October-29 February (2) in general, all marine areas within terri- Aythya fuligula torial limits are open to all Danish sportsmen, A. mania and the admission is free; (3) motorboats with Clangula hyemalis a maximum speed of 10 knots are allowed for Melanitta nigra shooting in the period 1 October-30 April; and M. fusca

(4) the shooting of seabirds is permissible Somateria mollissima from 1.5 h before sunrise to 1.5 h (in Decem- Bucephala clangula Mergus serrator ber 1 h) after sunset, whereas for most other M. merganser birds shooting is prohibited between sunset Gauia stellata and sunrise. G. arctica Shooting is a national tradition in Den- G. immer mark, and the large of has number sportsmen Podiceps cristatus considerable political power. Too much influ- Una aalge ence is given to the representatives of the U. lomvia hunters' organizations, which have the deci- A lea torda sive force in game committees dealing with ^Branta bernicla is fully protected since 1972. protective measures. It is difficult, therefore, to change the existing system. Shooting of seabirds, especially various 1974:171). Excessive duck shooting can, in waterfowl, is popular and intensive. The num- some cases, be controlled by banding in the ber of ducks taken by Danish sportsmen is breeding areas; the ensuing results then give probably in the order of 10-15% of the total rise to strong protests from the Scandinavian kill on the West European Flyway (Joensen countries against the extensive persecution. CONSERVATION OF MARINE BIRDS IN THE DANISH MONARCHY 273

As stated above, Denmark has (in relation to • murres, razorbill, great-crested grebe its size) the largest number of sportsmen of (Podiceps cristatus), and all species of loon any nation in the world and the most inten- should be fully protected; sive shooting. The number of sportsmen • it should be prohibited to shoot from shooting ducks and shorebirds per 100 km* is motorboats less than 1 km from the shoreline, 278 in Denmark, 28 in Sweden, 37 in Finland, as well as in certain narrow sounds and fjords;

10 in Poland, 83 in Holland, 164 in Britain, • it should be prohibited to shoot from and 129 in Western Germany; the number of shooting-punts less than 100 m from the ducks shot per 100 km'' is 1,856 in Denmark, shoreline;

39 in Sweden, 68 in Finland, and 129 in West- • it should be prohibited to sell waterfowl ern Germany (Nowak 1973). This shooting is and shorebirds shot, except for eider ducks undoubtedly of importance to dabbUng duck and mallards (Anas platyrhynchos); and populations, which are popular as shooting • no shooting should be allowed between objects everywhere in Europe. sunset and one hour before sunrise. Insofar as marine ducks are concerned, it can be seen in Table 2 that appreciable num- Oil Pollution is true for bers are shot in Denmark. The same Oil pollution incidents constitute one of the countries, whereas shoot- other Scandinavian greatest dangers to seabird populations in ing on the high seas is rather modest in most Danish waters. The enormous masses of sea- un- other European countries. The Danish bag birds present in these waters throughout the significant proportion doubtedly makes up a year, combined with the fact that Danish of the total number of marine ducks killed waters contain some of the heaviest shipping year, the total number of ducks each but when traffic in the world would give rise to anxiety in European waters is considered, the shoot- for oil disasters. The majority of all tanker ing pressure in appears to be of only Denmark traffic from the Atlantic and the North Sea to minor importance. However, the shooting, the Baltic passes through the Cattegat and from motor- particularly when undertaken the narrow straits of the Sound, the Great is such a dis- boats, so noisy and makes Belt, and the Little Belt, to supply a popula- turbance over large areas that the time for tion of about 100 million people. Up to seabirds to rest and forage is significantly re- 100,000 ships pass through these waters each duced. It must also be noted that the number year, half through the Sound. of pleasure craft is steadily increasing in the There have been severe oil pollution disas- period of prosperity, that increas- present and ters every year since about 1935, accom- ing numbers of sportsmen will probably make panied by enormous mortaUties of seabirds, use of the free shooting in territorial waters, particularly marine ducks. The Danish Game since it is becoming more and more expensive Biology Station, which has studied these to lease hunting areas. disasters (Joensen 1972a, 19726, 19736), has To restrict seabird shooting, the Danish noticed that the number of seabirds involved Ornithological Society has recently (1975) has increased in recent years, in spite of in- submitted a proposal to the Danish Govern- creased control by Danish authorities. ment, of which the following points are Unfortunately, it appears that small relevant: amounts of oil in the sea, originating from • The open season for dabbling ducks and cleaning the tanks of vessels, or from the re- geese should begin 15 September except for lease of a few tons of oil, are enough to create pintail (Anas strepera), shoveler (A. clypeata), mass mortality of seabirds when large concen- wigeon, and pochard— species which should trations of birds are present in the vicinity. not be hunted until 1 October; Such incidents have passed unnoticed in spite

~~• the open season for all diving ducks, as of control measures. In no case has the source well as for coot, should end 31 December; of the pollution been traced (Joensen~~

• the open season for the great cormorant 19726:27). There has not yet been a real "oil should be restricted to the period between 15 disaster" in the Danish waters similar to the September and 31 October; Torrey Canyon catastrophe. If such a disaster 274 F. SALOMONSEN

~~Table 4. Species composition of 8,304 birds killed by oil and examined in connection with five pollution disasters in the Cattegat, 1969-71. (After Joensen 1972:12.)~~

~~Oil incident no.~~

~~Species 1 2 3 4 5 Totals~~

Gauia stellata 1 9 1 4 15 G. arctica 2 2 4 8 16 Gavia sp. 4 1 5 Podiceps grisegena 4 1 8 8 21 P. cristatus 1 1 Phalacrocorax carbo 20 20 Anas platyrhynchos 2 2 4 A. clypeata 2 2 Aythya marila 6 2 8 Clangula hyemails 35 2 26 6 4 73 Melanitta nigra 387 241 521 262 77 1,488 M. fusca 197 33 417 223 119 989 Somateria mollissima 1,683 1,081 947 1,713 19 5,443 Bucephala clangula 3 3 13 9 28 Mergus serrator 48 28 28 2 106 Cygnus olor 10 17 1 28 C. cygnus 1 1 Fulica atra 1 1 2 5 9 Larus sp. 13 13 Alca tarda 1 12 1 14

~~Uria aalge 1 1~~

Cepphus grylle 1 2 16 19 Total birds examined 2,380 1,362 1,996 2,324 242 8.304 Estimated minimum number of birds killed 10,000 5,000 12,000 15,000 1,500 43.500 Percent of total birds contributed by three species'* 95.3 99.5 94.4 94.6 88.8 95.4

~~^Somateria mollissima. Melanitta nigra, and M. fusca.~~

takes place, the destruction of seabirds will be ter in March 1972 off the eastern coast of Jut- enormous and immeasurable. land, in the northern Cattegat, and another in As a result of five of the major oil pollution December 1972 in the Danish Waddensea, incidents in the Cattegat from 1969-71, a total both took place in areas critical to major con- of 43,500 birds were killed, of which 8,304 centrations of sea ducks. A total of more than

were examined and enumerated (Table 4). Al- 60,000 birds were killed, of which about 95% together, 21 or 22 species were involved, but consisted of the same three species of diving 95% of all birds examined were diving ducks: ducks mentioned above. These tragic events common eider and black and velvet scoters. represent a further increase in the annual mor- At present, it has not been possible to identify tality of birds caused by oil, and there is rea- any decrease in the number of these ducks in son to beUeve that a critical upper limit is Danish waters due to oil pollution. However, rapidly being approached. if these disasters continue, it can be expected It appears, however, that the measures that duck populations of northern Europe and taken by pollution control and naval authori- the Baltic area will be severely reduced, and ties have greatly improved in recent years. In that an overall decline will take place from January 1973, when a Polish merchant vessel which the birds may not be able to recover. collided with a Swedish tanker in the Sound, A particularly disastrous year was 1972, about 300 tons of heavy fuel oil were released when large numbers of ducks were killed as a into the sea. Several Danish and Swedish result of rather small oil spills. A tanker disas- ships working in cooperation succeeded in dis- CONSERVATION OF MARINE BIRDS IN THE DANISH MONARCHY 275

persing the oil, and no serious effect on sea- 70, as compared with the values earlier in this bird populations took place (Joensen century. Since 1970 there has been a sharp de- 19736:118). It seems that the best way of crease in mercury content, and in 1973 the cleaning up such oil disasters is through a me- level was almost as low as it was early in the chanical removal of the oil, but this is a very century. These results indicate that the strict expensive and difficult procedure. control of mercury discharges enforced in Sweden has resulted in a quick recovery of Pollution by Toxic Chemicals nearly normal conditions in the Baltic (Somer

Chemical pollution is probably the most and Appelquist 1974). However, recent ominous threat to seabirds at present. Since studies by Koeman et al. (1975:286) appear to show that all toxic chemicals used in agriculture ulti- mercury does not accumulate to the mately end up in the sea, and many large fac- same extent in seabirds as it does in seals. tories release their industrial wastes directly High concentrations of chlorinated hydro- into the sea, the effects of this pollution on carbon residues accumulate in carnivorous marine organisms is attracting a growing in- birds and upset the normal breeding behavior terest. Many students have worked on these by making the eggshells too thin and fragile problems, and the results that concern birds to survive (Peakall 1970:73; Mueller and were summarized by Bourne (1972:205). It is Leach 1974:289). In Denmark, shells of known that organochlorine residues have herring gull eggs from the Baltic population been found in seabirds in all the oceans of the were thinner, lighter, and more heavily con- world, including Antarctic waters and Arctic taminated with DDE and PCB than were seas (Bogan and Bourne 1972:358). The shells of eggs from other colonies (J0rgensen chemicals most often found in birds are DDE and Kraul 1974:173). This further emphasizes (a metaboUte of DDT) and PCB's (polychlori- the pollution of the Baltic Sea. nated biphenyls), a mixture of related chemi- Massive mortaUties of common murres, cal compounds often originating from indus- such as the one reported in the Irish Sea in the trial wastes. In addition, some mercury will fall of 1969 which was apparently caused always be found, sometimes in increased con- partly by malnutrition and PCB poisoning centrations. The present restrictions on the (Parslow and Jefferies 1973:87), are unknown use of DDT and PCB in Denmark have not yet in Danish waters. resulted in a corresponding decrease in the It should be added that the pollution of sea- amount of these pesticides in birds. water with cadmium, so very dangerous for It is well known that marine pollution man, has been high in recent years owing to reaches a peak in the Baltic. This high level of the increased use of this element in industry, pollution is reflected in seabirds. For example, but no analysis of its importance for seabirds analyses have shown that eggs from the in Danish waters has yet been made. colony of common murres on Christians0 in It should also be mentioned that pollution the Baltic contain about 100 times as much of fresh water in lagoons or lakes near the sea DDE and 50 times as much PCB as eggs of can often cause serious declines in numbers of murres from the Faroe Islands in the Atlantic certain seabirds. This is well illustrated by re- Ocean (Dyck 1975). cent events in the sanctuary Nakskov Indre- A similar difference exists in the mercury fjord on the island of LoUand. This landlocked content in birds examined in the two areas. fjord once supported numerous breeding Feathers of a large sample of black guillemots populations of ducks, grebes, and terns, but in and murres from the Cattegat and the Baltic recent years a number of species (e.g., eared had higher mercury levels than those from the grebe; common teal; garganey. Anas querque- Faroe Islands and Greenland. It is interesting dula; pintail; and black tern, Chlidonias nigra) that this difference existed over a hundred have failed to breed and practically all other years ago, as evidenced by the analysis of species have decUned in numbers. The main feathers in museum specimens. The Baltic reason for these changes is a severe pollution populations of both species show very signifi- from the admission of raw sewage from tribu- cant increases in the mercury content in 1965- taries (Bloch et al. 1972). After several out- 276 F. SALOMONSEN

~~breaks of botulism in recent years, procedures protection of seabirds, among which is a pro- to improve conditions are now being posal to stop egg-collecting.~~

developed. • Common property.—The Nature Conser- vancy Act regards all land not fenced in, even Other Threats to Seabirds small uninhabited islets, as common property. The most dangerous threats to seabirds are People have free access to such areas with the those discussed above. Authorities are aware result that seabirds breeding in colonies, or separately islands, visi- of these dangers and attempts are being made on are disturbed by tors arriving to improve conditions. Some results have by boat. At the same time, noisy motorboats, bathing parties, or been achieved in the combat against oil pollu- camping visitors frighten the birds, making successful tion, and the control of shooting is reaching breeding almost impossible. ornitholo- an acceptable level. Game management agen- Even gists, bird-banding teams, cies in Denmark and other Scandinavian and bird photog- countries (Norway, Sweden, and Finland) are raphers add to the destruction. The "Bird Is- cooperating on the request of the parliamen- land Group" of the Danish Ornithological Society tary body of the Nordic Council. If game has proposed a general prohibition biologists in these countries could agree on against visitors on important bird islands proposed changes in the game acts, owing to from 1 March to 15 July to protect the breed- the marked decline of a number of bird ing seabirds. species, the parliamentary basis for such a • Destruction by predators.— Fox, ermine, legal step would be absolutely certain. and stone-marten do not play an essential role. are important, small However, it must be admitted that the im- Rats more even on islands, destruction of tern pact of man on the environment is enormous, and have caused especially in a country Uke Denmark, which and gull colonies. Rat numbers do not decline possesses no raw materials, and where agri- until a severe winter with much ice occurs, or culture has transformed the whole country. In until high tide kills them all. Large gulls also such a country, the birds have to "face the cause a great deal of destruction, but crows music," and by this sharing of resources with and magpies are unimportant as predators in man, they will inevitably decrease in number. seabird colonies. Numbers of nonbreeding or It is the responsibility of biologists and politi- mute swans greylag geese may sometimes cians, without emotional biases, to find the be a nuisance, trampling eggs and nestlings in balance between the requirements of the two seabird colonies,

spheres of interest. • Forestry practices.—The prevailing prac- Many other dangers that threaten seabirds, tice of the forestry industry in Denmark of some of which are unrelated to human activi- not preserving old trees with holes has con- ties, are listed here. siderably diminished the breeding habitat of

• Land reclamation.— Reclamation of land hole-nesting species Uke the common mer- has reduced extensive areas of shallow water, ganser. Artificial nest-boxes have now been lagoons, marsh land, etc., from seabirds for established in several areas. foraging or breeding places. Draining and dik- • Sea conditions.— During high water, or ing of coastlands, estuaries, and saltings have rough sea, salt water may flood colonies of had the same effect. This activity is now al- breeding seabirds nesting on low islets, often most stopped, as these projects are no longer reducing the production of young. subsidized by the government. • Aircraft disturbance.—Disturbances are

• Egg-collecting.— According to the present also caused by noise from jet aircraft flying game act, collecting gull eggs is permitted low, especially in military training areas until 24 May. This creates much disturbance where air traffic may be heavy. on the breeding grounds, and eggs of terns • Commercial fisheries.—Modern commer- and shorebirds are also taken. This practice cial fisheries are depleting so-called indus- should be halted. The "Bird Island Group" of trially important fish stocks such as sand eels the Danish Ornithological Society, in a sym- (Ammodytes), herrings, and other small fish posium in 1972, prepared some rules for the over large areas of the sea for the production CONSERVATION OF MARINE BIRDS IN THE DANISH MONARCHY 277

of fish meal. This fishing has undoubtedly there are game reserves and governmental been the main reason for the decline in the forest reserves in Denmark. The game re- number of terns—especially sandwich terns serves are administered by the Ministry of which depend on these small fish species for Agriculture, which is also responsible for food. hunting legislation. The purpose of game re-

• Unknown factors at sea.—Large numbers serves is to support and protect the stock of of pelagic seabirds, particularly fulmars, kitti- game, which includes migrating birds. Shoot- wakes, and gannets, are washed up on the ing is usually prohibited, but a restricted western coast of Jutland in certain years (e.g., shooting season is allowed at some reserves. 1959, Joensen 1961:212). These birds died at More than 50 game reserves are now present sea, for unknown reasons, and apparently as a and functioning. Regulations differ widely result of food shortages or oil pollution. from reserve to reserve, but entry to some of them is not allowed in the breeding season. Conservation Many reserves are important for breeding or migrating waterfowl and some seabirds. In The threats to seabirds mentioned above fact, a total of 26 game reserves contain sea- are all well known to conservationists, who birds, the most important of which are the fol- are attempting to reduce the impact of these lowing: Ulvedybet (landlocked fjord at the factors on seabirds where possible. Insofar as Lim Fjord), Hjarbaek Fjord (landlocked fjord legal protection is concerned, it must be ad- with brackish water at the Lim Fjord), Fel- mitted that there are no marine sanctuaries in sted Kog (landlocked fjord at Nissum Fjord), Denmark, although several discussions have Jordsand (large stretches, almost 11,000 ha, taken place reviewing the possibility of estab- of the Danish Waddensea), Stavns Fjord (at lishing some in critical areas. There are, how- Sams6 Island), Esrum Lake (in northern Sea- ever, a number of sanctuaries on islands land), and Kalvebod Beach (at Amager Island, where seabirds breed. In the Sanctuary Act of near Copenhagen). 1936 these areas were called "Scientific Re- In the Nature Conservancy Act of 1969, dif- serves" because they were the site of scien- ferences between scientific and game reserves tific investigations of bird Ufe. All admission were abolished, although regulatory provi- was forbidden, at least during the breeding sions that were in force for the scientific sanc- season, and all shooting was prohibited, with tuaries were maintained. Unfortunately, the few exceptions. These sanctuaries were ad- amalgamation of the two types of reserve has ministered by the government's Nature given more power to the hunters' associa- Conservancy. tions, which constitute the majority of the ad- The following Scientific Reserves are impor- ministrative body of the reserves, the so- tant for seabirds: Hirsholmene Islands (in called Game Commission ("Vildtnaevnet"). Cattegat off Frederikshavn), Knotterne Is- However, any change in status of the original lands (small islets east of Laes6 Island), scientific reserves will not be tolerated by con- Vejlerne (diked in, landlocked fjords, densely servationists and other environmental groups covered with vegetation, at the Lim Fjord), in Denmark. Tipperne Peninsula and Klaegbanken Island (in Ringk^bing Fjord, western Jutland), Vars6 Island (Horsens Fjord, eastern Jut- The Faroe Islands land), and Graeholm Island (Christians*!* Archipelago, in the Baltic off Bornholm). A The number of seabirds in the Faroe Islands detailed description of these sites and their is greater than in any other region of the erection, bird life, and ornithological value North Atlantic, and is closely related to the was given by Salomonsen (1945). More re- extraordinary richness of the plankton. The cently, two additional Scientific Reserves high phytoplankton production is due to a have been established: Aegholm Islet (south strong vertical mixing of the water in the of Sealand), and Hessel^ Island in the south- northeast Atlantic, especially at the slopes of ern part of Cattegat. the submarine ridges, where both tidal cur- In addition to these scientific sanctuaries. rents and oceanic currents are usually strong. 278 F. SALOMONSEN

The resulting upwelling enriches the upper Table 5. Number of seabirds caught by layers of water with large quantities of nu- fowling each year in the Faroe Islands trient salts for the phytoplankton, and this, in in the early 1900's. (From Salomonsen turn, produces a teeming life of macroplank- 1935.) ton and fish on which the seabirds are de- Number of birds pendent (Salomonsen 1955). Species caught per year The enormous seabird population of the Faroes is apparent from the first description Una aalge 60,000 of the islands, "De mensura orbis terrae," a Fratercula arctica 270,000 document written in the year 825 by the Irish Puffinus puffinus 1,500 Fulmarus glacialis 80,000 monk Dicuilus, who described the most char- Morus bassanus 1,300 acteristic feature of the Faroes as being the Total 412,800 fact that "the islands were full of various kinds of marine birds." This richness has remained to the present, and has provided an important source of food for the resident hu- The annual number of seabirds caught by man population, particularly in former times. fowling in the early 1900's (summarized in There are few, if any, countries in the world in Table 5) were reported in Salomonsen (1935). which wild-fowling and other exploitations of This large harvest of birds, taken by fowling birdlife have played such a major role as in the year after year for centuries, did not appear to Faroes. A number of elaborate and varied influence the seabird populations, as bird bird-catching methods were invented, and numbers remained stable. However, in recent these have remained essentially the same for years, shooting and a special form of snaring at least the last 500 years. Bird-fowling at of murres have increased dramatically and great heights on precipitous sea-cliffs was a seem to have endangered the murre popula- dangerous venture, and each year lives were tion. The annual number of murres killed is es- lost. The main thing, however, was that food timated to be about 120,000, of which 70,000 obtained from fowling meant life and death are snared and at least 50,000 shot (estimates for local inhabitants and so was undertaken in of birds shot range from 50,000 to 100,000). such a well-balanced way that the seabird This total is almost double the number of populations did not decrease or disappear. birds caught during fowling, and because of Some fowling still takes place, but on a re- an apparent decline in murre numbers the produced scale, since most men are now engaged vincial government decided to investigate the in the fishery during the summer. Shooting is matter, and in 1972 the Danish Ornithological now of much greater importance than in for- Society agreed to conduct the study. Figures mer times. from the 1972 census of murres (Table 6) show The Faroese game acts (from 1897, 1928, that almost 600,000 birds were counted, from and 1954) are very severe and show a broad which an estimate of more than 393,000 consideration for birdlife. Practically all ter- breeding pairs was calculated (Dyck and Mel- restrial birds, including shorebirds, are pro- tofte 1975). In spite of this large number, tected, and existing regulations permit people Dyck and Meltofte (1975) concluded that the to catch or shoot only common murres, razor- Faroese murre population has declined by bills, puffins, shags (Phalacrocorax aristo- about 20% during the last 10-15 years. Inves- telis), fulmars, gannets, parasitic jaegers tigations are under way to monitor further {Stercorarius parasiticus), and gulls, as well as changes in murre numbers, and to determine a few "pest" species like crows (Corvus the trend, and whether reductions in shooting corone) and ravens (C. corax). The legal right and snaring are necessary to maintain the of fowling on a "fowling cliff" belongs to the population. registered owner of the land on which the cliff Oil pollution is practically unknown in is situated. There are some sound restrictive Faroese waters, but since drilling for oil will laws for these cliffs. For example, shooting probably take place in the near future, the im- within 3.2 km of any seabird colony is portance of oil to birds in this region may prohibited. change. Toxic chemicals do not appear to be CONSERVATION OF MARINE BIRDS IN THE DANISH MONARCHY 279

Table 6. Colonies of the common murre, Table 7. Distributions of seabirds breeding in Uria aalge, on the Faroe Islands, based Greenland in relation to marine zones. on a census conducted in 1972. (After Marine zone and species^ Dyck and Meltofte 1975.) Boreo-panarctic Number of Fulmarus glacialis birds Number of Somateria mollissima Colony observed pairsa Stercorarius parasiticus Suderoy 73,945 49,500 Rissa tridactyla Litla Dimun 13,220 8,800 Sterna paradisaea St6ra Dimun 68,050 45,600 Cepphus grylle Skuvoy 213,800 143,200 Fratercula arctica Sandoy 101,710 68.100 Panarctic Hestur 17,290 11,600 Larus hyperboreus Mykines 14,500 9,700 Uria lomvia Vagar 4,224 2,800 Clangula hyemalis Streymoy 27,214 18,200 Gavia stellata Eysturoy 10,520 7,000 High arctic Kalsoy 14,150 9,500 Somateria spectabilis Vidoy 5,980 4,000 Branta bernicla {hrota) Fugloy 22,730 15.200 Stercorarius longicaudus Totals 587,333 393,200« Xema sabini Larus thayeri aThe "number of pairs" is calculated by multiply- Pagophila eburnea ing the number of birds observed by 0.67 (Dyck Cepphus grylle (mandti group) and Meltofte 1975). Plautus alle Fratercula arctica (naumanni) Phalaropus fulicarius Low arctic involved in the decline in murres. Investiga- Larus glaucoides tions of concentrations of chemical pollutants Phalaropus lobatus in their eggs show that levels of DDE (mean Boreo-low arctic 1.1 ppm), PCB (mean 2.0 ppm), and mercury Mergus serrator (mean 0.2 ppm) (Dyck and Meltofte 1975) are Phalacrocorax carbo (carbo) Larus marinus relatively low and unlikely to affect reproduc- Alca torda tion (Dyck and Meltofte 1975). Levels are Uria aalge much smaller than those found in seabirds in Cepphus grylle {grylle group) Britain, the Baltic, or in albatrosses in the Fratercula arctica (arctica) Pacific (Fisher 1973). Boreal Larus ridibundus Greenland ^A few species breed near freshwater lakes, but are marine during the nonbreeding season. Greenland, which has an area of 2,175,600 km^ and extends for a distance of 2,670 km from the northernmost to the southernmost point of the country, is almost a continent by itself. The range of the different species of sea- Table 7. The terrestrial area of southernmost birds, therefore, is greatly varied, and it is West Greenland belongs to the subarctic zone necessary to classify them according to the of the boreal province, and one boreal bird relation between their distributions and the species, the black-headed gull, has bred there marine zones. A description of the zones of in recent years. It is, however, as much a the marine environment in the North Atlantic freshwater bird as a marine one. was given by Salomonsen (1965), and the The widely differing ranges of Greenland breeding distributions of seabirds in Green- seabirds are shown in Figs. 1-4 and are based land based on this system are given in on my new and previously unpublished data. 280 F. SALOMONSEN

Fig. 1. Breeding range in Greenland of four boreo-panarctic seabirds, Fulmarus glacialis. Somateria mollissima, Rissa tridactyla, and Fratercula arctica. CONSERVATION OF MARINE BIRDS IN THE DANISH MONARCHY 281

Fig. 2. Breeding range in Greenland of three boreo-panarctic seabirds, Sterna paradisaea, Cepphus grylle, and Stercorarius parasiticus, and one low arctic species, Phalaropus lobatus. 282 F. SALOMONSEN

Fig. 3. Breeding range in Greenland of three panarctic seabirds, Uria lomvia, Larus hyperboreus, and Clangula hyemalis, and one high arctic species, Stercorarius longicaudus. CONSERVATION OF MARINE BIRDS IN THE DANISH MONARCHY 283

~~Fig. 4. Breeding range in Greenland of three boreo-low arctic seabirds, Mergus serrator, Larus marinus, and Phalacrocorax carbo, and one high arctic species, Plautus alle. a~~

~~284 F. SALOMONSEN~~

The borderline between the high arctic and system is beginning to break down, and it can- low arctic zones is situated in Melville Bay on not be permitted to continue. The provincial the west coast, and just south of Scoresby government is aware of this fact, and various Sound on the east coast; the innermost parts legal enactments have been issued from both of Scoresby Sound belong to the low arctic the government and the local magistrates. zone. However, since the size of the police force In the low arctic Pacific region the number (mostly Greenlanders) is small, it is of little of seabirds is said to be about 51 million in help for the preservation of wildlife, and some- summer and 8 million in winter (Sowl and times even the policemen themselves do not Bartonek 1974). No similar estimate is avail- know the local ordinances. The result has been able for low arctic West Greenland, but I sug- that seabirds, previously profusely flourish- gest that it is much lower in summer and ing, have considerably decreased in number in slightly higher in winter. West Greenland.

The human population of Greenland, now I have previously described the shooting numbering about 50,000 individuals, is re- and hunting of seabirds in Greenland and the stricted to the seashore, where all cities and statutory provisions issued to protect them minor outposts are situated. Although shoot- (see Salomonsen 1970). At present, the following seabirds is an ancient tradition in Green- ing seabirds and their eggs are totally pro- land, the true landbirds, which are few in num- tected: whooper swan; common puffin, Frater- ber, are usually left alone. Seabirds collected cula arctica; and harlequin duck, Histrionicus by shooting provide an important source of histrionicus. Some other species have a closed food that the Greenlanders could not do with- season or are protected in certain parts of the out. Since special shooting and hunting regu- country: snow goose, Anser caerulescens; lations have not been developed in Greenland, common eider; king eider, Somateria spectabi- these activities often resemble a sort of lis; great cormorant; dovekie, Plautus alle; slaughter rather than true hunting. There is black guillemot; and thick-billed murre, Uria no game act in Greenland, and practically all lomvia. Furthermore, all catching and hunt- birds can be shot. This condition is similar to ing of birds within 2 km of breeding colonies that in Canada, where according to Section of murres and kittiwakes is prohibited. Bird 5(7) of the Migratory Birds Regulations sanctuaries where hunting, catching, and col- (Canadian Wildlife Service, Ottawa 1973) "an lecting of eggs and down are prohibited are Indian or Inuk may at any time, without a Avsigsut, Nunatsiaq, and Satuarssunguit is- permit, take auks, auklets, guillemots, lands, which are scattered in Disko Bay, and murres, puffins and scoters and their eggs for Tasiussarssuaq Fjord (the inner part of Arfer- human food and clothing." Much the same siorfik Fjord, south of Egedesminde). sort of hunting privileges exist for native However, the Greenland Provincial Council peoples of Alaska. What is still worse, how- has been alarmed by the serious decline in the ever, is the enormous illegal shooting of numbers of seabirds due to increases in ducks, geese, swans, and cranes that is known human persecution, and it has decided to in- to take place in arctic North America, but is troduce a game law similar to those in Den- largely ignored by police and game authori- mark and other European countries. The prep- ties. Bartonek et al. (1971) described this aration of this legislation was left to me, and a situation very well for Alaska. In Greenland, draft of this Greenland game act has been it is not possible any more to distinguish be- issued (Salomonsen 1974); the new law was tween "native Eskimos" and Greenlanders passed in parliament in 1977 and went into (including Danes working in the country), but force on 1 January 1978. the attitude toward animals among the in- It is not possible to review in detail the dif- habitants is the same as it has always been— ferent parts of the new law, but certain impor- food source to hunt and kill. tant points should be mentioned. In northern With a rapidly growing human population, parts of West Greenland (north of Egedes- and a readily available supply of guns and minde) the sea is ice-covered for 7-8 months a speedboats for hunting, the whole natural eco- year, and seabird hunting is therefore not pos- a

~~CONSERVATION OF MARINE BIRDS IN THE DANISH MONARCHY 285~~

sible outside the breeding season. Because of Council for Bird Preservation in Texel to the this, it was necessary to allow some hunting Danish Government, it was stated that the of murres, eiders, and immature gulls during annual incidental drowning of murres prob- the breeding period, but away from nesting ably involved about 250,000 individuals— locations. Consumption of seabirds is to be figure exceeding the reproductive capacity of hmited to local residents, and sales to can- the species. This estimate was doubted by neries for shipment to other cities is to cease. Danish fishery biologists, but recent investi- Previously, canneries in northwest Greenland gations carried out by the Canadian Wildlife exported large numbers of thick-billed murres Service and the Fisheries Research Board of to South Greenland—e.g., 25,606 birds in Canada have shown that the figure is even 1971; and 30,029 in 1972 (Anonymous greater, and that the total kill amounts to 1974:64). This marketing of murres will end. about half a million murres annually (TuU et Other parts of the proposal important for al. 1972). seabirds include: Because of this mortality of murres, an

~~• A general closed season extending from 15 agreement was reached between the Ameri- June to 15 August. can and Danish governments, namely that:~~

• Prohibition of shooting at breeding colonies of seabirds, as is in force at present (cf. From 1 January 1976, all salmon fisheries above). outside the 12-mile boundary shall totally stop. In the years 1972-75 the fishery carried out by • Eggs of terns and gulls can be collected for Danish and Faroese fishermen shall be reduced food in southwest Greenland to 1 July, and in gradually from 800 to 300 tons of fish, and shall northwest Greenland to 10 July; fulmar and terminate on 31 December 1975. The fish quota also collected in northwest murre eggs can be by Greenland fishermen must amount to no Greenland. more than 1,100 tons annually, but from 1976 • Each hunter is allowed to shoot or catch 50 onwards, the fishery shall be restricted to areas birds per day, but the entire bag must be used within the 12-mile limit. for human consumption.

• All shooting from speedboats, aircraft, This agreement, which has drastically re- and motor vehicles is prohibited. duced the number of murres caught, was dis- • Catching flightless common eiders, king cussed at a meeting of the International Com- eiders, and oldsquaws {Clangula hyemalis) is mittee of North Atlantic Fisheries in May prohibited. 1972, and was ratified by the countries in-

• Practically all seabirds and shorebirds can volved in July 1972. be shot; all other birds (except rock ptarmigan Oil pollution has never occurred in Green- and raven) are totally protected. land, but concessions for offshore oil drilling The principles of this radical new act must along the West Greenland coast have just be taught to the population by all possible been granted by the Danish Government, and means of communication, including radio, this new development gives rise for concern. public meetings, schools, etc. However, it is clearly stated in the concession that the Ministry for Greenland can lay down Another matter of great concern to seabirds rules for protection against oil pollution and in Greenland is the Atlantic salmon fishery other damage to human or animal life, and can off the west coast by Danish, Greenlandic and adopt measures to fight pollution which has foreign fishermen. It is well known that many already taken place (section 5(9)). It is up to birds are killed in the fishing gear, and a the concessionary to oversee industrial de- serious political controversy has arisen, espe- velopments in the area and see that marine cially between the governments of the United pollution is avoided (section 11). States and Denmark. The fact that a large Toxic chemicals have been found in Green- number of thick-billed murres were drowned land seabirds, as everywhere else in the world, in salmon gill nets during their southward but it must be emphasized that no pesticides swimming migration along the Greenland whatsoever are in use in Greenland itself. In- coast was significant. In a resolution sent by vestigations by Somer and Appelquist (1974) the XV World Conference of the International indicated that the mercury content in black 286 F. SALOMONSEN

guillemots in Greenland has doubled over the Bloch, D. 1971. Ynglebestanden af knopsvane (Cyg- nus olor) i Danmark 1966. Danske Vildtunder- last 20 years, and has now reached 2 ppm, s^gelser 16. 47 pp. which is, however, a relatively low figure. Bloch, D., C. H. Ovesen, B, H. Fenger, J. Jensen, Levels of DDE, PCB, and aldrin in Greenland and J. Pedersen. 1972. Vildtreservatet Nakskov birds were investigated by Braestrup et al. Indrefjord. Resume af biologiske, kemiske og (1974). Common eider, king eider, harlequin fysiske undersgelser i 1970-1971. Vildtbiologisk Station, Kal<^, R^nde. 15 duck, and oldsquaw, as well as thick-billed pp. Bogan, J. A., and W. R. P. Bourne. 1972. Organo- great cormorant, were examined; murre and chlorine levels in Atlantic seabirds. Nature all were found to be contaminated with pesti- (Lond.) 240(5380):358. cides, although to varying degrees. Highest Bourne, W. R. P. 1972. Threats to seabirds. Int. concentrations occurred in the cormorant, Counc. Bird Preserv. Bull. 9:200-218. Braestrup, L., J. Clausen, and O. Berg. 1974. DDE, which contained 6.5-15 ppm of DDE and 14.1- PCB and aldrin levels in arctic birds of Green- 46.7 ppm of PCB. These specific differences land. Bull. Environ. Contam. Toxicol. 11(4):326- appear to show that the pesticide level in the 332. different species of seabirds is influenced Dyck, J. 1975. Milj^gifte i danske fugle. Panda- more by the position of the bird in the food Nyt. Verdensnaturfonden 1975(1):11-13. chain than by its migratory habits. Dyck, J., and H. Meltofte. 1975. The guillemot Una And finally, I wish to mention a more happy aalge population of the Faeroes 1972. Dansk Ornith. Foren. Tidsskr. 69:55-64. event. On 9 May 1974 a new law of nature pro- Fisher, H. I. 1973. Pollutants in North Pacific alba- tection in Greenland was passed by the trosses. Pacific Sci. 27(3):220-225. Danish Parliament. According to this law, a Joensen, A. H. 1961. Disaster among fulmars (Ful- National Park is to be established covering al- marus glacialis (L.)) and kittiwakes (Rissa tri- most the entire northeast and north regions of dactyle (L.)) in Danish waters. [Danish with Eng- lish summary.] Dansk Ornith. Foren. Tidsskr. Greenland, from the Thule District in north- 55:212-218. ern West Greenland around the entire north Joensen, A. H. 1972a. Oil pollution and seabirds in coast of Greenland and south along the east Denmark 1935-1968. Dan. Rev. Game Biol. 6(8):1- coast to the northern inner parts of Scoresby 24. Joensen, A. H. 19726. Studies on oil pollution and Sound. All hunting, fishing, egg-collecting, seabirds in Denmark 1968-1971. Dan. Rev. Game and disturbances to the environment are for- Biol. 6(9):l-32. bidden in this enormous area. This is by far Joensen, A. H. 1973a. Moult migration and wing- the greatest National Park in the world, feather moult of seaducks in Denmark. Dan. Rev. covering about 800,000 km^ Of this total Game Biol. 8(4):l-42. Joensen, A. H. 19736. Danish seabird disasters in area, the greater part is a lifeless icecap, to be 1972. Mar. PoUut. Bull. 4(8):117-118. sure, is ice-free land but about 200,000 km^ Joensen, A. H. 1974. Waterfowl populations in Den- and suitable habitat for numerous high-arctic mark 1965-1973. A survey of the non-breeding birds. populations of ducks, swans and coot and their shooting utilization. Dan. Rev. Game Biol. 9(1):1- 206. J6rgensen, O. H., and I. Kraul. 1974. Eggshell References parameters, and residues of PCB and DDE in eggs from Danish herring gulls, Larus a. argen- Anonymous. 1974. Gr^nland 1973, Arsberetning. tatus. Ornis Scand. 5(2):173-179. Vol. 4. Ministeriet for Gr^nland, Copenhagen. Koeman, J. H., W. S. M. van de Ven, J. J. M. de 106 pp. Goejj, P. S. Tjioe, and J. L. van Haaften. 1975. Atkinson-Willes, G. L. 1972. The international wild- Mercury and selenium in marine mammals and fowl censuses as a basis for wetland evaluation birds. Sci. Total Environ. 3:279-287. and hunting rationalization. Pages 87-110 in Mardal, W. 1974. Ternegruppen. Feltornithologen Proc. Int. Conf. Conserv. Wetlands Waterfowl, 16:4-7. Iran 1971. Mueller, W. J., and R. M. Leach, Jr. 1974. Effects of Bartonek, J. C, J. G. King, and H. K. Nelson. 1971. chemicals on egg shell formation. Annu. Rev. Problems confronting migratory birds in Alaska. Pharmacol. 14:289-303. Trans. N. Am. Wildl. Nat. Resour. Conf. 36:345- Nowak, E. 1973. Hunting kill statistics investiga- 361. tion. Int. Waterfowl Res. Bur. Bull. 35:26-30. Bloch, D. 1970. The mute swan {Cygnus olor) breed- Parslow, J. L. F., and D. J. Jefferies. 1973. Relation- ing in colony in Denmark. [Danish with English ship between organochlorine residues in livers summary.] Dansk Ornith. Foren. Tidsskr. 64:152- and whole bodies of guillemots. Environ. PoUut. 162. 5:87-101. CONSERVATION OF MARINE BIRDS IN THE DANISH MONARCHY 287

Peakall, D. B. 1970. Pesticides and the reproduction vation in northern circumpolar lands. Interna- of birds. Sci. Am. 222(4):72-78. tional Union for Conservation of Nature and Salomonsen, F. 1935. Aves. In R. Sparck, ed. Zool- Natural Resources, Morges, Switzerland. ogy of the Faroes 3(pt.2) (lxiv):269 + 6 suppl. A. F. Salomonsen, F. 1974. Forslag til vedtaegt om jagt H^st, Copenhagen. pa fuglene i Gr

i Danmark og deres Fugleliv. Fauna och Flora ring af Det gr^nlandske Landsrad. Tidsskr. 40:250-261. Gr<6nland 1974(5):155-172. Salomonsen, F. 1954. The Danish game-statistics. Somer, E., and H. Appelquist. 1974. Changes and [Danish with English summary.] Dansk Ornith. differences in mercury level in the Baltic and Foren. Tidsskr. 48:123-126. Kattegat compared to the North Atlantic using Salomonsen, F. 1955. The food production in the Uria sp. (guillemot sp.) and Cepphus grylle (black sea and the annual cycle of Faeroese marine guillemot) as indicators. 9th Conf. of the Baltic birds. Oikos6(l):92-100. Oceanographers, Kiel. 12 pp. Danish Isotope Salomonsen, F. 1963. Oversigt over Danmarks Centre, Copenhagen. fugle. [With explanatory notes in EngUsh.] Sowl, L. W., and J. C. Bartonek. 1974. Seabirds— Munksgaard, Copenhagen. 156 pp. Alaska's most neglected resource. Trans. N. Am. Wildl. Nat. Resour. Conf. 39:117-126. Salomonsen, F. 1965. The geographical variation of Strandgaard, H. 1964. The Danish bag record. I. the fulmar (Fulmarus glacialis) and the zones of Studies in game geography based on the Danish marine environment in the North Atlantic. Auk bag record for the years 1956-57 and 1957-58. 82:327-355. Dan. Rev. Game Biol. 4(2):1-116. Salomonsen, F. 1968. The moult migration. Wild- TuU, C. E., P. Germain, and A. W. May. 1972. Mor- fowl 19:5-24. tality of thick-billed murres in the West Green- Salomonsen, F. 1970. Birds useful to man in Green- land salmon fishery. Nature (Lond.) 237(5349):42- land. Pages 169-175 in Productivity and conser- 44.

~~Present Status and Trends in Population of Seabirds in Norway~~

Einar Bnin*

~~University of Troms0 Troms<), Norway~~

~~Abstract~~

The most numerous seabird in Norway is the puffin {Fratercula arctica), but its current breeding population of 1.25 million pairs is slowly declining. The kittiwake ijiissa tridactyla), however, is increasing and establishing new colonies; its population now stands at 510,000 pairs. The population of the common murre (Una aalge), the seabird species most vulnerable to human activity, was about 160,000 breeding pairs in 1964 but is now decreasing at a rate of nearly 5% per year. Of the other alcids, the razorbill (Alca tarda) and thick-billed murre {Uria lomvia) show similar declines, and the black guillemot (Cepphus grylle) is maintaining a stable population. The fulmar {Fulmarus glacialis) and the gannet (Sula bassana) have both spread from the British Isles and have established a number of breeding colonies in Norway during this century. Evidently immigration of gannets is still occurring, since the observed rate of increase far exceeds the population's intrinsic rate of increase. The impact of human activity on bird mor- taUty varies from species to species. The two most serious factors are coastal oil pollution and the use of fishing gear; direct hunting pressure accelerates the decline of murres and razorbills. Persistent toxic chemicals are not yet a serious problem in Norway.

Norway, with a coastline of more than ance were very limited, and the work was con- 20,000 km, an abundance of islands, and areas centrated on cliff-breeding seabirds, particu- of offshore upwelUng, provides good condi- larly the gannet (Sula bassana), fulmar (Ful- tions for a rich seabird fauna. A regional marus glacialis), kittiwake (Rissa tridactyla), study of this seabird fauna has been under- razorbill (Alca tarda), common murre (Uria taken as a sideUne of basic marine research. aalge), thick-billed murre (U. lomvia), and Although the ultimate aim has been to evalu- puffin (Fratercula arctica). Until 1970, the ate the importance of seabirds in the energy study involved making annual censuses in the flow of a marine ecosystem, a more realistic approximately 20 major colonies of cliff- problem (given priority so far) has been to breeding seabirds and mapping the distribu- study yearly production and the dynamics be- tion of the quantitatively less important hind changes in the breeding populations. colonies. Good population estimates are of funda- Since 1970, the Norwegian seabird program mental importance to studies of population has also involved more detailed studies in of dynamics. Because the available censuses some selected colonies. In these colonies, em- seabirds in Norway were few and largely in- phasis has been on investigation of yearly pro- adequate, a long-term program was started in duction and of the factors limiting this pro- 1961. In the beginning, resources and assist- duction, and evaluation of the effects of the population growth. 'Deceased. human activity on

~~289 290 E. BRUN~~

~~Material and Methods~~

The logistics of census operations have COMMON PUFFIN gradually improved from the use of slow, local Fratercula arctica transportation to the use of fast pneumatic boats and, in more recent years, seaplanes. Various census methods have been used, depending on species and circumstances. For puffins, a method based on measurement of feeding frequency and on the number of puffins per time unit that pass a particular observation post when they return from the feeding ground was used (Brun 1971a). Kitti- wakes and gannets were readily censused by a combination of photographic methods and de- 19716). tailed counts in sample areas (Brun • 1-10 pairs breeding Direct counting is by far the most accurate • 11-100 method for razorbills, murres, and fulmars; 9 101-1000 murre, but in the larger colonies of common ^ 1001-10.000 lack of time permitted accurate counts for A 10.001-100.000 only a limited proportion of the cliff. Direct counts of individuals, the egg/chick ratio, and ^^ 100.001-1.000.000 estimates of the relative size of the censused population were used to estimate the total population of the colony. V.V In a colony of kittiwakes near Troms0, environmental factors that limit breeding success, Fig. 1. Distribution of the puffin {Fratercula arctica) in Norway. Numbers refer to localities listed in such as temperature and wind exposure, were Table 2. monitored throughout the breeding season on a data recorder, and detailed measurements of temperatures on and inside the eggs have way is the puffin (Fig. 1), which is the only been recorded. For further information about species with a breeding population of more the influence of environmental parameters on than 1 million breeding pairs (Tables 1, 2). In incubation rhythm and nest attendance, the a 1964 census (Brun 1966) the total breeding presence of the male and female at a par- population was put at 1.5 million pairs. The ticular nest was recorded by using radioactive current figure of 1.25 million pairs includes bands and a Geiger-Muller tube connected to several newly discovered colonies and some a pen recorder. not censused in 1964; it is more accurate than In a study of the effects of human activity, the previous census for most of the 15 largest egg samples of selected species were analyzed colonies which make up 99.9% of the total for mercury, PCB, and DDT derivates. An ef- population. The puffin population is concen- fort was also made to obtain figures for the trated in Troms and Nordland (94%), with mortality caused by oil pollution and fishing only about 3% in Finnmark. gear as well as by direct hunting pressure. Kittiwake (Rissa tridactyla) Results The second most numerous seabird species in Norway is the kittiwake, which dominates Status and Trends of in a number of the larger cliff colonies. Its dis- Cliff-breeding Species tribution pattern differs from that of the puffin—the main occurrence of the kittiwake Puffin (Fratercula arctica) population (about 63%) is in Finnmark

~~By far the most numerous seabird in Nor- (Table 3). PRESENT STATUS AND TRENDS OF SEABIRDS IN NORWAY 291~~

~~Table 1. Estimate of the numbers of seabirds breeding on the coast of Norway 1970-1974. Species are listed in descending order of breeding population size.~~

~~Increase ( + ) or Species Th mds of pairs^ decline (-)~~

Fratercula arctica 1250 _ Rissa tridactyla 510 + Larus argentatus (260)b + L. canus (150)b + Uria aalge 100 - L. marinus (40)b + Phalacrocorax aristotelis 33 + Alca torda 30 - Cepphus grylle 22 Sterna paradisaea (21)b - S. hirundo (13)b - Phalacrocorax carbo 12 + L. fuscus 9b +

~~Stercorarius parasiticus (8) L. ridibundus 4b + Fulmarus glacialis 1.1 + U. lorn via 1.0 - Hydrobates pelagicus 9 ? Sula bassana 0.76 + Oceanodroma leucorrhoa ? 9~~

~~^Numbers in parentheses are not based on a complete census of the coast, t'ln addition, an unknown number of pairs breeding inland.~~

The annual production of kittiwakes shows has increased much more rapidly (Brun enormous variation, both throughout the 1971c). coastline and in different years; however, at Common murre (Uria aalge) our sample stations in north Norway, the The common murre (Fig. 2) has shown a mean production in 1974 (Table 4) was more considerable decrease. The most spectacular stable and was near the minimum value neces- is S0r-Fugl0y, where a colony of sary to maintain zero population growth. decrease at pairs in 1940 was reduced to 4,000 This minimum production, mx (number of 10,000 pairs in 1961, to 1,100 pairs in 1966, and to females produced per breeding female), can be only about 10 breeding pairs in 1974 (Table 5). computed from survival rates Most of the census work was done in 1964 and 1974. The general trend in population change, mx = (l-P)/lx = 0.13/0.57 = 0.23 as expressed by the yearly decrease or increase, has been extrapolated forward to 1974 where P is annual adult survival and Ix is sur- or back to 1964 for those colonies where cen- vival of fledged chicks up to first breeding. missing for either of these years, to Data on survival are taken from Coulson and suses were enable a better comparison (Table 6). The White (1959) and from Norwegian banding overall in Norwegian colonies of the recoveries. decrease is, thus, near per year; the The kittiwake has, however, established a common murre 5% cases with a positive trend are based number of new colonies, and although the few either on very small figures or on extrapola- local increase in some of these is spectacular, tion from old, inadequate censuses. the long-term change during the last 15 years is only about 1 % increase per year in northern Thick-billed Murre (Uria lomvia) Norwegian colonies (E. Brun, unpublished data). In southern Norway, the population The thick-billed murre (Fig. 3) was first 292 E. BRUN

~~Table 2. Status of the puffin (Fratercula arctica) in Norway (cf Fig. 1).~~

~~Year of Number of Percent of Locality census pairs population~~

~~1. Kj0r 1975 80 <0.1~~

~~2. Heglane 1970 4 <0.1~~

~~3. Ferkingstad0yene 1970 5 <0.1 4. Utsira 1970 2 <0.1~~

~~5. Utvaer 1970 200 <0.1 6. Ryggsteinen 1970 2 <0.1~~

~~7. Veststeinen 1970 1,500 0.1 8. Einevarden 1970 1,500 0.1 9. Svin0y 1970 100 <0.1 10. Runde 1974 30,000 2.4 ll.Sal0y 1970 2 0.1 12. Sklinna 1974 2,000 0.2 13. Lovunden 1968 60,000 4.8~~

14. Fugl0y i Gildeskal 1968 800 0.1 15. R0st 1964 700,000 55.7 16. Vaer0y 1974 70,000 5.6 17. Nykvag 1967 40,000 3.2 18. Frugga 1975 5,000 0.4 19. Anda 1970 10,000 0.8 20. Bleik 1968 40,000 3.2 21.S0r-Fugl0y 1968 40,000 3.2 22. Nord-Fugl0y 1967 218,000 17.3 23. Loppa 1968 180 <0.1 24. Hjelms0y 1964 20,000 1.6 25. Gjesvaerstappen 1973 18,000 1.4 26. Kongs0y 1966 30 <0.1 27. Syltefjord 1966 100 <0.1 28. Horn0y 1967 160 <0.1 29. Rein0y 1967 40 <0.1 Total 1,257,705 100.0

proved to breed in Norwegian colonies in tion was estimated at 36,000 pairs in 1966-69 1964; it was then found at three localities and (Brun 19696); some more recent censuses has since been found breeding at eight locali- show a definite decline, but data are not suffi-

ties (Table 7). It is now fairly certain that the cient to estimate the overall decline in the thick-billed murre is not a newcomer but has Norwegian population. At most, the current remained unnoticed among the common breeding population is 30,000 pairs. murre for generations, possibly since the original immigration of the Una species after the last glacial period. Data are not sufficient Fulmar (Fulmarus glacialis) to show whether this small population of The fulmar is one of two species of seabirds thick-billed murres is decreasing at the same that have spread from colonies in the British rate as the common murre. Isles and established themselves as breeding birds in Norway during this century (the nazorbill (Alca torda) other is the gannet). Another colonial cliff-breeding alcid, the The fulmar began nesting in the early razorbill (Fig. 4), has a distribution pattern 1920's on Runde, the only sizeable seabird very similar to that of the common murre, but colony in south Norway, off Alesund. Further the individual colonies (Table 8) are, with one immigration of birds from the British Isles exception, smaller. The total breeding popula- probably occurred in the first 25 years, when PRESENT STATUS AND TRENDS OF SEABIRDS IN NORWAY 293

~~Table 3. Status of the kittiwake (Rissa tridactyla) in Norway, and a comparison of distribution with that of the puffin (Fratercula arctica).~~

~~Breeding pairs~~

~~Rissa Fratercula Number Number County (thousands) Percent (thousands) Percent~~

Finnmark 321 62.9 38 3.0 Troms 9 1.8 258 20.5 Nordland 72 14.1 928 73.7 Tr0ndelag (S, N) 1 0.2 2 0.2 M0re and Romsdal 105 20.6 30 2.4 Sogn and Fjordane 1.9 0.4 3 0.2 Rogaland 0.1 — <0.1 — Total 510 100.0 1,259 100.0

the population increased about 10% annually Runde in 1971 was about 700 pairs (Table 9). to about 350 pairs in 1947 (Valeur 1947). Since From Runde, fulmars have spread not only to then the population increase has slowed down a number of islands in the same region, but to about 3% annually, and the population on also much farther afield— south to Utsira

~~COMMON MURRE THICK-BILLED MURRE~~

~~Uria aalge Uria lomvia~~

~~• 1-10 pairs breeding • 11-100~~

~~101-1000 % • 1-10 pairs breeding 1001-10.000 • 11-100 • 101-1000 A 10.001-100.000~~

Fig. 2. Distribution of the common murre (Uria Fig. 3. Distribution of the thick-billed murre (Uria aalge) in Norway. Numbers refer to localities lomvia) in Norway. Numbers refer to localities listed in Tables 5 and 6. listed in Table 7. 294 E. BRUN

~~RAZOR BILL AIca tarda~~

~~1-10 pairs breeding 11-100 101-1000~~

~~1001-10.000 ^ • 11 - 100 pairs breedii # 101-1000~~

~~Ni^V''~~

Fig. 4. Distribution of the razorbill iAlca torda) in Fig. 5. Distribution of the gannet (Sula bassana) in Norway. Numbers refer to localities listed in Norway. Numbers refer to localities listed in Table 8. Table 10.

(59°18'N, 4°55'E) and north to Bleik (69°3'N, change. Like the fulmar, it was established in 15°42'E). The total Norwegian population of 1946 on Runde, and the first individuals were fulmars in 1971 was estimated at 1,100 pairs. undoubtedly of British origin. During its entire breeding history on Runde, and also in Gannet (Sula bassana) two of the three new colonies in northern Nor-

The gannet (Fig. 5), the most recently estab- way established in the 1960's, the yearly in- lished and least numerous of the cliff-breeding crease has far exceeded the intrinsic rate of in- seabirds, has the best-known population crease (Table 10); for gannets with a 50% breeding success, adult mortality of 6%, and 35% survival up to first breeding, the intrin- Table 4. Annual production, nix, of the kitti- sic rate of increase is about 2% per year. The wake (Rissa tridactyla) at some North Runde and Syltefjord colonies are naturally Norwegian coastal localities (nix — num- protected by their inaccessibility, but the ber of females produced per female). colonies at Mosken and Nordmjele, which are on small islets, are both easily accessible. The Sample size Nordmjele colony, however, has been effec- Locality Year (number) mx tively protected from its start, whereas the Ved0y, R0st 1972 852 0.21 Mosken colony has been open to visitors; this Hekkingen, Troms 1974 264 0.46 difference is probably reflected in their dif- Hjelms0y 1974 357 0.18 ferent breeding success and annual growth Jarfjord 1974 146 0.31 rate (Table 11). The breeding success neces- Total 1,619 0.25 sary to maintain a stable population with the PRESENT STATUS AND TRENDS OF SEABIRDS IN NORWAY 295

~~Table 5. Status of the common murre (Uria aalge) in Norway (cf. Fig. 2).~~

~~Last census Previous census~~

~~No. of No. of breeding breeding Locality Year pairs Year pairs Reference~~

1. Utsira 1970 1 1950 10 Holgersen 1951 2. Utvaer 1970 17 1948 55 Willgohs 1952 3. Veststeinen 1970 29 1950 40 Willgohs 1952 4. Klovningen 1970 35 1950 20 Willgohs 1952 5. Einevarden 1970 30 1952 25 Willgohs 1955 6. Runde 1974 6,000 1963 7,600 Brun 1969a 7. Storholmen 1970 8 — — 8. R0st 1974 6,800 1964 9,700 Brun 1969a 9. Vaer0y 1974 1,750 1964 2,400 Brun 1969a 10. Nykvag 1974 350 1966 430 Brun 1969a ll.Bleik 1974 60 1952 90 Regnell 1957 1964 75 Brun 1969a 12. S0r-Fugl0y 1974 10 1940 10,000 Soot-Ryen 1941 1961 4,000 Brun 1963 1966 1,100 Brun 1969a 13. Nord-Fugl0y 1967 9,000 1963 15,000 Liitken 1965 14. Loppa 1974 500 1966 800 Brun 1969a 15. Hjelms0y 1974 70,000 1964 110,000 Brun 1965 1967 95,000 Brun 1969a 16. Gjesvaerstappene 1973 580 1967 750 Brun 1969a 17. Svaerholtklubben 1973 20 1966 25 Brun 1969a 18. Omgangsstauran 1973 70 1967 85 Brun 1969a 19. Syltefjorden 1974 9,000 1966 12,300 Brun 1969a 20. Horn0y 1974 500 1964 730 Brun 1969a 21. Rein0y 1974 110 1964 160 Brun 1969a 22. Kj0fjord 1970 21 — — 23. Skoger0y 1970 8 1967 6 Brun 1969a 24. Sagfjord 1970 9 1967 12 Brun 1969a 25. Kobbholmfjorden 1970 2 1967 1 Brun 1969a

mortality figures given above is 34%: the cliff-breeding species dealt with so far, notes have been made on all seabirds observed nix = (l-P)/lx = 0.66/0.35 = 0.17 during numerous flights along the Norwegian coast. Although a first attempt at putting a For equal sex ratio, breeding success is 2 figure to all seabird species in Norway may be times mx = 0.34. somewhat premature, it is believed that even A British ringed gannet from Ailsa Craig an extrapolation combined with an educated (55°12'N, 5°07'W) was found nesting when 4 guess is of some value until more accurate years old in the Nordmjele colony in 1970 censuses covering the whole coast can be (Brun 1972), giving direct evidence that immi- made. Although the data (Table 1) are gration from colonies in Great Britain (Scot- arranged in the same way as the results from land) still takes place. "Operation Seafarer" in the British Isles (Cramp et al. 1974), it must be stressed that the accuracy of the Norwegian figures, at Estimates of Total Seabird least for the noncliff-breeding birds, is far in- Population in Norway ferior to the very fine British data. The table includes data for two petrels (Hydrobates In addition to the more detailed censuses of pelagicus, Oceanodroma leucorrhoa), which in .

~~296 E. BRUN~~

Table 6. Population trends in colonies of the common murre (Uria aalge) in Norway. Num- bers for 1964 and 1974 are, when not censused those years, extrapolated from present trends, using estimated yearly decrease or increase from all available census figures.

~~Percentage yearly Number of breeding pairs^ decrease (-) or~~

~~increase ( Locality 1964 1974 + )~~

~~1 Utsira 2 1 -12.2~~

~~2. Utvaer 23 14 -5.5~~

~~3. Veststeinen 32 27 -1.6~~

~~4. Klovningen 30 39 +2.8~~

~~5. Einevarden 28 31 + 1.0 6. Runde 7,438 6,000 -2.2~~

~~7. Storholmen 9 7 (-2.2)b.c~~

8. R0st 9,700 6,800 -3.6 9. VaBr0y 2,400 1,750 -3.2 10. Nykvag 453 350 -2.6 ll.Bleik 75 60 -2.3 12. S0r-Fugl0y 1,844 10 -68.5 13. Nord-Fugl0y 13,201 3,681 -13.6 14. Loppa 900 500 -6.1 15. Hjelms0y 110,000 70,000 -4.6 16. Gjesvaerstappen 853 556 -4.4 17. Svaerholtklubben 27 19 -3.2 18. Omgangsstauran 94 68 -3.3 19. Syltefjorden 13,299 9,000 -4.0 20. Horn0y 730 500 -3.9 21. Rein0y 160 110 -3.8 22. Kj0fjord 21 20 (-0.4)b.c 23. Skoger0y 5 12 + 10.1 24. Sagfjord 16 6 -10.1 25. Kobbholmfjord 1 5 + 26.0 Total 161,341 99,566 -4.9

~~^Numbers in italics were censused from 1964 and 1974. ^Estimated values from trends in neighboring colonies. •^Numbers in parentheses are not based on a complete census of the whole coast.~~

~~Table 7. Status of the thick-billed murre (Uria lomvia) in Norway (cf. Fig. 3).~~

~~No. of Percentage of breeding total Uria Locality Year pairs population~~

~~l.Ved0y, R0st 1974 15 0.3 2. Vaer0y 1966 20 0.9 3. Hjelms0y 1974 850 1.2 4. Gjesvaerstappene 1973 25 4.3 5. Syltefjord 1970 90 0.9 6. Horn0y 1966 55 8.1~~

~~7. Rein0y 1964 1 0.6 8. Kj0fjord 1970 1 4.8 Estimated number, Norway, 1974 > 1,000 ca. 1.0 .~~

~~PRESENT STATUS AND TRENDS OF SEABIRDS IN NORWAY 297~~

~~Table 8. Status of the razorbill (Alca torda) in Norway (cf. Fig. 4).~~

~~No. of Locality Year breeding pairs Percent~~

1. Kj0r 1970 1 <0.1 2. Utsira 1970 25 0.1 3. Utvaer 1970 16 0.1 4. Veststeinen 1970 22 0.1 5. Klovningen 1970 12 <0.1 6. Einevarden 1970 45 0.2 7. Runde 1974 2,800 9.5 8. Sklinna 1974 15 0.1 9. Lovunden 1968 8 <0.1 10. R0st 1974 3,900 13.2 1 1 Vaer0y 1974 800 2.7 12. Nykvag 1966 250 0.8 13. Bleik 1968 28 0.1 14. S0r-Fugl0y 1974 15 0.1 15. Nord-Fugl0y 1967 10,000 33.8 16. Loppa 1969 750 2.5 17. Hjelms0y 1974 7,000 23.7 18. Gjesvaer 1973 2,500 8.5 19. Svaerholtklubben 1973 18 0.1 20. Omgangsstauran 1973 6 <0.1 21. Kongs0y 1966 8 <0.1 22. Syltefjorden 1966 1,200 4.1 23. Horn0y 1967 65 0.2 24. Rein0y 1967 55 0.2 25. Kj0fjord 1970 9 <0.1 26. Skoger0y 1970 4 <0.1 27. Jarfjordnes 1970 3 <0.1 Total ca. 30,000

Norway breed on R0st (well north of the Arc- totelis), and great cormorants (P. carbo) are tic Circle), where they have adapted to a de- present in similar numbers. The most striking layed breeding season with egg laying in difference is the very small number of procelli- August because of the confUct of their noc- forms and gannets in Norway compared to turnal habits with the continuous daylight Britain and Ireland, where they are almost as due to the midnight sun. Of the present popu- numerous as the gulls and the auks. lation trends that are given for each species in

Table 1, all auks except the black guillemot {Cepphus grylle) are decreasing, whereas the gulls, the gannets, the fulmars are in- and Table 9. Status of the fulmar (Fulmarus creasing. glaciaUs) in Norway. Since the coastUne of Norway is about the same length as the coastline of Great Britain Number of of breeding and Ireland, it is interesting to compare the Number County localities pairs population figures (Table 12), although the accuracy is very different. Populations of Nordland 6 140 auks and gulls are similar in both areas, but M0re and Romsdal 7 945 the species composition is different. There are Sogn and Fjordane 2 11 more terns in the British Isles, but skuas Rogaland 2 2 Total 17 1,098 (Catharacta skua), shags {Phalacrocorax aris- 298 E. BRUN

~~Table 10. Population increase of the gannet (Sula bassana) in Norway (cf. Fig. 5).~~

~~Mean yearly No. of breeding pairs Year growth rate Colony established 1969-1974 (%) 1969 1970 1971 1972 1973 1974~~

~~1. Runde 1946 8.4 330 331 383 422 450 494~~

~~2. Mosken ca. 1960 5.4 50 83 77 60 62 65~~

~~3. Nordmjele 1967 83.3 7 36 65 103 127 145~~

~~4. Syltefjord 1961 14.5 28 29 44 48 51 55 Total 12.8 415 479 569 633 690 759 Yearly growth rate(%) 15.4 18.8 11.2 9.0 10.0~~

~~Discussion Table 11. Comparison of annual growth rate and breeding success in two colonies Impact ofHuman Activity ofgannets (Sula bassana).~~

Mosken Nordmjele Direct Exploitation Annual Breeding Annual Breeding According to Norwegian laws, all seabirds, growth success growth success with the exception (for some odd reason) of rate (%) rate (%) the gannet and fulmar, can be hunted from 21 1969 62 — August to 1 March. However, only the two 1.66 5.14 1970 51 61 species of murre and the razorbill are still 0.93 1.81 1971 36 46 regularly hunted and, although no statistics 0.78 1.58 1972 33 62 support it, an estimate based on interviews 1.03 1.23 1973 50 35 1.05 1.14 with some of the hunters reveals that murres 1974 12 39 and razorbills are shot in the ratio of about 1969- 50:1. One man can shoot as many as 380 1974 1.05 40 1.83 46 murres and razorbills during a winter season as a sidehne to fishing. Although not many hunt on this scale, an absolute minimum of 5,000 murres and razorbills are killed this way auks' nests, egg collecting is now both less at- each season. tractive and less important. Human dis- A new law based on modern principles of turbance of the breeding colonies, however, is conservation has been under consideration for gradually becoming a more serious factor. several years, and this will mean an improve- Fishing ment. However, the speed of the decline of the Gear auks, particularly the murres, makes it im- Although on a scale different from that in perative to stop this hunting immediately, western Greenland, drift-net and longline fish- and it is of very little economic importance to ing for Atlantic salmon {Salmo salar) outside the few who take part. Some illegal "fishing" the 19-km (12-mile) limit off the northern Nor- for auks still takes place at R0st and Vaer0y, wegian coast present a serious mortality where fishnets are anchored over wooden hazard to some seabirds. ReUable data exist frames outside the auk colonies at the begin- only for the longline fisheries. In the 1969 sea- ning of the nesting season. At Ved0y on R0st son (with 75 effective days from mid-March to in 1972, up to 80 murres were taken daily. mid-June), one boat using 1,040 hooks per day Thus an estimated total of 500-700 murres caught 294 birds: 52 fulmars, 3 gannets, 43 were taken that year—about 5% of the breed- kittiwakes, 107 murres, and 89 puffins. No ing population on this island. razorbills were identified, but they may have Egg collecting was important during World been included in the murre figure. If this War n, but in these more affluent times and sample is representative, the 100 or so Nor- because of the relative inaccessibility of the wegian boats using longUnes plus about 20 PRESENT STATUS AND TRENDS OF SEABIRDS IN NORWAY 299

~~Table 12. Comparison of the number of seabirds breeding on the coasts of Great Britain and Ire- land (Cramp et al. 1974) and on the coast of Norway.~~

~~Number of breeding pairs"~~

~~Species Great Britain and Ireland Norway~~

Fulmarus glacialis 306,000 1,100 Puffinus puffinus > 175.000 — Hydrobates pelagicus 10^orlO« 10' or 10^ Oceanodroma leucorrhoa 10^ 10^ Sula bassana 138,000 760 Phalacrocorax carbo 8,100 12.000 P. aristotelis 31,000 33.000 Stercorarius skua 3,100 lb

S. parasiticus 1,100 8,000 Larus ridibundus 74,000 4,000"^ L. canus 12,000 (150,000)c L. fuscus 47,000 9,000c L. argentatus 333,000 (260,000)c L. marinus 22,000 (40,000)<: Rissa tridactyla 470,000 510,000 Sterna sandvicensis 12,000 —

S. dougalli 2,300 — S. hirundo 14,000 (13.000)'= S. paradisaea (31.000) (21.000)^= S. albifrons 1,800 — A lea tarda (144,000) 30.000 Uria aalge (577,000) 100.000 U. lomvia — 1.000 Cepphus grylle 8,300 22,000 Fratercula arctica (490,000) 1,250,000 Total ca. 3,000,000 ca. 2,500,000

~~"Numbers in parentheses are not based on a complete census of the whole coast. ^New in 1975 (Wim Vader, personal communication). cJn addition, an unknown number of pairs breeding inland.~~

Danish boats (which used 4,000-6,000 hooks is an exceptionally high figure. The total loss per day and consequently caught more birds) of diving seabirds in pound nets per year in would have caught roughly 10,000 fulmars, Norway (about 6,000 nets fishing for 40 days) 600 gannets, 9,000 kittiwakes, 21,000 murres, was estimated to be at least 40,000 birds in and 18,000 puffins in the 1969 season. The 1969. The data are too unreliable to give drift-nets in Norwegian waters are reported to species composition, however, since fishermen be less damaging to seabirds than are the rarely make note of this. longlines, but even without adding the figures Amounts of fish offal from offshore from the drift-nets, the numbers are substan- trawlers, drift-netters, and longline fishing tial in view of the size of the Norwegian breed- boats have increased in recent years, and ing populations. some seabirds, particularly kittiwakes, ful- Use of fishing gear close inshore, especially mars, and gannets make use of this new and pound nets set near colonies of diving sea- readily available food source. Thus, although birds, can take a heavy toll under special the use of fishing gear is a serious threat to weather conditions. In 1969 at Runde, 85 seabird survival, fish waste from the same birds, mainly auks, shags, and some diving boats provides an abundant food supply for ducks, were caught in one net in 24 hours; this the more pelagic species. 300 E. BRUN

Pollution Natural Factors Influencing No quantitative investigation similar to Breeding Success those made in Great Britain, Netherlands, The factors discussed so far are all and Belgium (Tanis and Bruyns 1968) has results of human activities which directly or indi- been carried out on the impact of oil pollution rectly influence seabird mortality. Yearly pro- on seabirds in Norway. The northern Nor- duction or breeding success is, wegian population of the most threatened however, also influenced by a number of natural factors species, murres and razorbills, winter in such as food supply, availability of suitable North Sea coastal areas where oil pollution nest sites, predation, climate (weather), and oiled birds have most frequently been and population-dependent factors (age, breeding found. It is possible that whole populations experience, population density). For the winter every year in the same area, and if they gannet, whose breeding happen to be in a heavily polluted area, a par- success has been studied in some detail (Brun it ticular population may be seriously affected. 1974), was concluded that the differences in exposure (to Such an occurrence is believed to have caused severe weather) in breeding the dramatic decline in the S0r Fugl0y popula- and experience were the most important factors responsible tion (cf. Table 5). for annual fluctuation in breeding Although not yet serious, pollution by per- success. For such species murres, razorbills, sistent toxic chemicals such as organo- as and puffins, food supply is an important limiting chlorines and mercury is a problem even in northern Norway, because the northbound factor. If the spawning of the fish species that coastal current brings water masses, plank- constitute their main food items fails 1 year for some reason, it difficult ton, and nekton from areas with industrial may be very for the seabirds to find an adequate alternative wastes. Analysis of the eggs of herring gull food supply and most of the chicks starve to (Larus argentatus), murre, razorbill, and kitti- death. To a lesser degree, food supply is limit- wake in 1972 showed relatively low levels of ing for the kittiwake, to mercury; the only species with a relatively which seems be more influenced by bad weather (Norderhaug et al. high level of mercury (mean 0.58 ppm) was the 1977). gannet (Fimreite et al. 1974). This elevated toxic burden may have caused a reduced breeding success for the gannet. Analysis of Conclusion concentrations of PCB's and DDT/DDE showed that the levels of these organo- Two opposite population trends have been chlorines were generally also lower in Nor- observed— the decline of the coastal-bound wegian seabirds in those than of Britain (Fim- murres and razorbills and the increase and reite etal. 1977). spread of the more pelagic gannets, fulmars, and kittiwakes. These changes are attributed Protection and Necessary to a number of factors, which include the Conservation Measures following:

Total protection of some of the important • The diving murres and razorbills spend a seabird colonies (including the surrounding major part of their time swimming on the sur- nearshore waters) has proven very effective, face and are thus more susceptible to surface especially when the protection is so strict that oil pollution than are the pelagic species. landing is prohibited for a specified period • The coastal-bound murres and razorbills during incubation and fledging. However, to are quite heavily hunted, whereas there is no reduce the rapid decrease of some species, a regular hunting of the pelagic species. total hunting prohibition of those species • The pelagic species are mainly surface must be instigated, oil pollution must be re- feeders and do not swim under water, and are duced, and the fisheries must be regulated to thus less affected by the drift-nets than are reduce the mortality caused by fishing gear. diving birds. PRESENT STATUS AND TRENDS OF SEABIRDS IN NORWAY 301

• The pelagic species are the principal bene- Brun, E. 1971c. Population changes of some sea- ficiaries of recently increased supply of fish birds in south Norway. (In Norwegian, English summary.) Sterna 10:35-56. offal from trawlers. Brun, E. 1972. Establishment and population increase of the gannet Sula bassana in Norway. Ornis Scand. 3:27-38. Acknowledgments Brun, E. 1974. Breeding success of gannets Sula bassana at Nordmjele, And0ya, north Norway. The program was originally sponsored by Astarte 7:77-89. Troms0 Museum, later University of Troms0, Coulson, J. C, and E. White. 1959. The post-fledging mortality of the kittiwake. Bird Study 6:97- and has been financially supported by the 102. Norwegian Research Council for Science and Cramp, S.. W. R. P. Bourne, and D. Saunders. 1974. Humanities and the Norwegian Game Fund. The seabirds of Britain and Ireland. Collins, The research grants are gratefully acknowl- London. 287 pp. Fimreite, N., J. E. Bjerk, N. Kveseth, and E. Brun. edged. I also thank my field assistants and 1977. DDE and PCBs in eggs of Norwegian sea- the many local people at the breeding sites birds. Astarte 10:15-20. who have been most helpful. Fimreite, N., E. Brun, A. Fr0slie, P. Frederichsen, and N. Gundersen. 1974. Mercury in eggs of Nor- wegian seabirds. Astarte 7:71-75. Holgersen, H. 1951. Investigations of seabirds in Rogaland 1949-1950. (In Norwegian, English summary.) Stavanger Mus. Arb. 1950:61-76. Lutken, E. 1965. The breeding birds on Nord- References Fugl0y, north Norway, their distribution and numbers. (In Danish, English summary.) Dansk Brun, E. 1963. Ornithological features of Nord- Orn. For. Tidsskr. 58:166-193. Fugl0y and S0r-Fugl0y. Astarte 1(22):1-13. Norderhaug, M., E. Brun, and G. U. M0llen. 1977.

Brun, E. 1965. Brunnich's Guillemot, Uria lomvia Barentshavets sj0fuglressurser. Forhold i tilk- (L.), as a breeding bird in Norway. (In Norwegian, nytning til status, milj0problemer of forshning- English summary.) Sterna 6:229-250. soppgave. Medd. Norsk Polar Inst. 104:1-119. Brun, E. 1966. The breeding population of puffins Regnell, S. 1957. Fran det nordnorska fagelberget (Fratercula arctica) in Norway. (In Norwegian, Bleiks0ya. Fauna Flora, Upps. 52:199-202. English summary.) Sterna 7:1-17. Soot-Ryen, T. 1941. The seabird rookeries of Troms Brun, E. 1969a. The breeding distribution and county. (In Norwegian, English summary.) population of guillemots {Una aalge) in Norway. Troms0Mus. Aarsh. 62(1):1-112. (In Norwegian, English summary.) Sterna 8:209- Tanis, J. J. C, and M. F. M. Bruyns. 1968. The im- 224. pact of oil pollution on seabirds in Europe. Proc. Brun, E. 19696. The breeding distribution and Int. Conf. Oil Pollution of the Sea 1968:67-74. population of razorbills (Alca tarda) in Norway. Valeur, P. 1947. Havhesten og havsula pa Rund0y. (In Norwegian, English summary.) Sterna 8:345- Naturen 70:370-379. 359. Willgohs, J. F. 1952. On the distribution of some Brun, E. 1971a. Census of Puffins {Fratercula arc- seabirds in western Norway. Univ. Bergen Arb. tica) on Nord-Fugl0y, Troms. Astarte 4:41-45. 1951 Naturvit. Rekke(9):l-20. Brun, E. 19716. Breeding distribution and popula- Willgohs, J. F. 1955. Om forekomsten av endel tion of cliff-breeding seabirds in S0r-Varanger, kyst- og sj0fugl pa Vestlandet. Fauna, Oslo 8:16- north Norway. Astarte 4:53-60. 27.

~~SYMPOSIUM SUMMARY~~

~~Conservation of Marine Birds of Northern North America—A Summary~~

~~Ian C. T. Nisbet Massachusetts Audubon Society Lincoln, Massachusetts 01773~~

This is not going to be a straightforward of 10 points that I will first list and then summary of the conference because it is my elaborate on. view that a number of important topics have • We know that we are discussing a very im- not been addressed. In particular, what was portant biological resource which has been supposed to be the main theme of the confer- neglected for a long time. ence—the need for conservation of marine • We know roughly what this resource con- birds of northern North America— has been sists of and which aspects of it are biologically taken for granted by many speakers and has important. been treated by others in what may be a mis- • We know why this resource is in its leadingly brief way. So instead of simply sum- present condition, and we know something marizing the information that has been pre- about the ways in which it is related to other sented in the papers, I want to give my own resources. views about how we should use this informa- • We know a certain number of things that tion to make a case for the conservation of the birds do which make them vulnerable to marine birds. I feel strongly that we can make changes in the environment. a good case for conserving them, and that we • We know that the resource has already know enough to start doing so. The task of been disturbed in the past, both by human-in- making a case for conservation and of propos- duced and by natural changes, and we know ing priorities for action has been left to me as that it has already been damaged. the conference summarizer. • We can identify at least some of the major Particularly in the first half of this confer- threats that the resource will face in the next ence, we heard a long series of accounts of the few years. birds of the area which stressed our ignor- • We know that the resource can be con- ance—large amounts of information that was served, at least to a modest and partial ex- not known and large amounts of research that tent. needed to be done. Now, I have an unexpected • We have a fairly good idea of what we advantage over most of these speakers in that ought to do now to start conserving the

I have very little direct experience in the area. resource. What I learned from their papers, not having . We have some ideas— so far rather rough any very clear picture of the islands, the birds, and ill-formulated—about why we should con- their habits, or the food that they eat, is that serve the resource. we already know quite a lot about the marine . We know— or so I beUeve—that it is prac- birds of northern North America. We cer- ticable and economically feasible to conserve tainly know enough to decide what we ought the resource. to do next and how to take the basic steps in I am sure that there will be some disagree- conserving them. ments with some of these assertions, espe- After Ustening to the presentations, read- cially with the last two, so I will give reasons ing the abstracts, and studying the maps why I beUeve that we should conserve these posted in the conference hall, I drew up a Ust birds and that we can afford to do so. 305 I

~~306 I. C. T. NISBET~~

Magnitude and Importance spectacular island colonies, particularly in the Bering Sea and the of the Resource Aleutian Islands, some of which have a remarkable variety of species. Several different definitions of "seabird" The papers in the first half of the conference have been used at this conference, but cer- which reviewed the abundance and distribu- tainly there are dozens, and probably scores, tion of the birds in the northern North Pacific of genuine marine species that either breed in Ocean, the Bering Sea, and adjacent seas sug- the area or use it as a major nonbreeding area. gested that we are dealing with numbers of The collection of birds in the area of the North birds of the order of 100 million. That is 100 Pacific and the Bering seas seems more im- million birds at sea plus some unknown num- pressive in terms of both abundance and di- ber of millions of birds along the shore. We do versity than anything in the north Atlantic not have to take these numbers Uterally— Ocean, which has been so more fully am sure that the persons who produced them much studied. did not mean them to be taken literally— but certainly we are talking about something on As to the uniqueness, there has been almost the order of tens of millions and not much no mention of the endemic species at the con- more than some hundreds of millions. At ference. It is therefore important to empha- least, it is on the order of a hundred million size in this summary that a significant group rather than ten million or a biUion. I do not of marine or coastal birds is endemic to this think it an exaggeration to say that this is one area. These birds include the red-legged kitti- of the great neglected biological resources of wake {Rissa spp.), the Aleutian tern (Sterna the world. aleutica), the spectacled eider {Somateria fischeri), the emperor goose {Philacte canagica), and the red-faced cormorant {Phalacro- Characteristics of the corax urile); a number of alcids, including the Resource whiskered {Aethia pygmaea), parakeet (Cyc- lorrhynchus psittacula), crested {A. cristatella), and least auklets {A. pusilla); the Three important aspects of this resource horned puffin {Fratercula corniculata); and have not been identified clearly in the papers Kittlitz's murrelet {Brachyramphus breviros- delivered at the conference, in part because tris). In addition, we should not forget some the papers summarizing the biological sur- migrants that make exclusive use of this area veys did not include much of the detail that in their nonbreeding season. These include the was available in the maps posted in the con- short-tailed albatross {Diomedea albatrus), ference hall. [Maps in this volume do not show the scaled petrel {Pterodroma inexpectata), the detail of those posted.] These are the and I believe also Cook's petrel {P. cookii), numerical abundance of the birds, their diver- which has not previously been mentioned. sity, and their unique characteristics. From the little we know about its off-season As to abundance, figures have been men- distribution, the short-tailed albatross ap- tioned on the order of 50 million for shear- pears to use these waters exclusively; hence it waters (Puffinus spp.) and 25 million for has as much claim to be regarded as an endan- murres (Uria spp.). For other species the gered species of the United States as the quoted numbers have been less specific, but I whooping crane {Grus americana). would estimate from what I have read and heard that the total population must run into Perusal of the hsts of species presented at miUions for eiders (Somateria spp.), kitti- the conference brings out one important wakes (Rissa brevirostris), and fulmars (Ful- point. Although we are meeting in the United marus glacialis), and doubtless for other States and have been looking at the birds species. The numbers of the smaller alcids, in from a United States-Canadian viewpoint, particular, must be very great. this is truly an international resource in al- As to diversity, there is an impressive num- most every respect that I have mentioned. ber of species and a wide variety of habitats. The most abundant species, in terms of both We have been shown in the photographs some numbers and biomass, is probably the short- SYMPOSIUM SUMMARY 307

tailed shearwater, a migrant from the south- detail, preferably with a photographic record, ern hemisphere. The rarest species, and the so that they can be resurveyed in later years most endangered, is the short-tailed alba- to determine whether substantial population tross, which breeds only on one island in changes have taken place. Criteria for selec- Japan. There are migrants in large numbers tion of sample colonies for inclusion in this from Chile, AustraUa, New Zealand, and espe- base-Une survey should include not only cially the Soviet Union. All of these use the numerical size and species diversity but also area of ocean and shallow sea that we have ease of access, ease of observation, and the been considering as a major area for a sub- practicability of obtaining good photographic stantial part of their annual cycle. records. What more do we need to know about the extent of this resource? In my opinion we should not place high priority on determining Ecology and Functioning the exact numbers of the birds— whether of the Resource there are 25 milUon or 26 milUon murres, for example. It would be difficult, if not impos- In the opening session of this conference, sible, to determine such numbers in the kind several speakers reviewed our general knowl- of geographical and cUmatic area we are con- edge of the ecology of seabirds; others sum- sidering. Moreover, even if we were to meas- marized our specific knowledge of the birds of ure the populations with great accuracy and the North Pacific, Bering, and adjacent seas, to determine in a few years that they had and their relation to physical and biological changed by 10%, we would not be able to factors in the environment. There is no need draw any conclusions about the reasons for to summarize these reviews again here except the change or what should be done about it. to point out that information on the relation To set priorities for further exploration, I between the birds and the marine environ- think it is more important to survey in greater ment is being generated very rapidly. We are detail the general distribution of the breeding beginning to understand the factors that con- colonies. So far, we know the location of only trol the breeding distribution of the individual the largest colonies; we know almost nothing species, their foraging strategies, and their about the colonies of a mere 10,000 pairs or dispersion at sea, at least in summer. How- less. So I think future surveys should concen- ever, it is clear from what has been said at this trate on locating the medium-sized colonies conference that we know much less about and getting some impression of roughly how their ecology and distribution in winter. This many smaller colonies there are. It is impor- lack of information is important because con- tant to locate and be sure that we know of all flicting opinions have been expressed as to the major colonies that have a considerable whether factors operating in the winter range number of species; these large, diverse colo- or at the breeding colonies are more critical in nies should be given priority for conservation. Umiting population size. Most important of all, we need to locate and It is evident from what was said in the open- survey the endemic species with some preci- ing session that the distribution of the birds is sion. This need is especially great for the very closely related to the distribution of species that we suspect are Umited to small marine resources. It is clearly no accident that areas or that may otherwise be particularly the distribution of large numbers of many vulnerable. species of birds coincides with that of the If we are to measure population changes major fisheries. Similarly, it is no accident over the next few decades, it is of course es- that there is a relation between the distribu- sential to have a good base-line survey. How- tion of birds and the extent of the continental ever, I do not think it is either practicable or shelf. These coincidences, which reflect the desirable to try to inventory the entire popu- fundamental dependence of both birds and lation of breeding seabirds with great accu- fish upon marine productivity, set the stage racy. A more realistic and worthwhile pro- for existing and further conflicts between con- gram would be to select some sample colonies servation of the birds and human exploitation and to catalogue these sample areas in some of other resources of the area. 308 I. C. T. NISBET

Perhaps the most significant gap in our term changes in the environment. Short-term knowledge of North Pacific seabirds is in the perturbations in the environment are usually area of productivity and demography. As far not reflected quickly by changes in total popu- as I can judge, we know almost nothing about lation—certainly not by changes that we can the breeding success of these birds, their post- measure with the accuracy of our present-day fledging survival, their longevity, their age at census techniques. Many of the man-made first breeding, the age structure of their popu- changes we are concerned about are short- lations, the fluctuations in their breeding per- term. To identify their effects we should look formance, or their survival from year to year. not for changes in total population but rather For most species, we lack even the most basic for changes in biological parameters, such as life history and life table information. the first-year survival rate or the number of If we can argue by analogy from studies young raised. I therefore suggest that some of made in other parts of the world, including the the most critical parameters to be measured North Atlantic, we can make some basic are changes in age structure of populations. generalizations that we would expect to apply We should therefore select as biological moni- to the birds of our area. We know that as a tors species that can readily be aged— for class seabirds have some peculiar characteris- example, gulls, which have a sequence of dis- tics which make them difficult to manage and tinguishable inmiature plumages. cause some of the problems we have in con- In specifying gaps in our knowledge of the serving them. In general, they are long-lived ecology of birds, we should set clear priorities and breed slowly, most lay small clutches, and rather than compile a long "shopping list" of the historical experience is that they take a research projects. On the basis of the fore- very long time to recover from depletion of going survey, I would suggest the following population. Many have an irregular breeding as priority items for further study. First, we performance; some have long series of bad need to know a lot more about winter distribu- years interspersed with occasional years of tion, not only of the marine birds, but also of good breeding success. Many seabird popula- inshore and coastal species. Second, we need tions have traditionally fluctuated, as exem- to study in greater detail the relation between plified by those of the North Atlantic, whose the day-to-day distribution of birds and the fluctuations were described by W. H. Drury local patchiness of the resources on which and W. R. P. Bourne. they depend. Evidence that seabirds are able Some species of seabirds are conservative, to locate and use fluctuating and shifting food staying in the same colonies for many years or sources has been given by several speakers at generations. Others are volatile, dispersing the conference. We need to understand how freely from one site to another and forming birds locate these resources and what relation new colonies in an unpredictable way. Sea- this has to their survival and vulnerability to birds exhibit a wide range of ecological adap- human activities. There is a special need to tations; some are highly specialized, others study the ecology of endemic species because are highly generalized and adaptable. These their conservation is of special importance. differences can be very important when their We need to learn more about the relation of environment changes, as D. N. Nettleship's the birds to the conimercial fisheries, both to film "Puffins, predators, and pirates" graphi- resolve existing or alleged conflicts and to cally illustrated. avert future problems. As M. T. Myres pointed out on the 1st day However, I believe that the highest re- of the conference, seabird populations exhibit search priority should be given to obtaining both short- and long-term fluctuations. Long- basic information on reproductive success and term fluctuations are those that take place life table data for some representative species. over times comparable to the generation time Clearly, we cannot study many species in de- of the species, which may be many years or tail, but in selecting key species for such even decades for some seabirds. By surveying studies we should pick a variety of ecological populations and measuring changes in them, types—for example, at least one generalist we usually obtain information only about species and one specialist, one sedentary long-term population trends, reflecting long- species and one migrant, one species at a high SYMPOSIUM SUMMARY 309 trophic level and one at a low trophic level. Past Damage to For the purpose for which we convened this the Resource symposium—conservation— I do not think need detailed knowledge of the factors that we In the speech opening the symposium. As- which regulate populations. Such knowledge sistant Secretary Reed referred to this bio- is, of course, of immense biological interest logical resource as still relatively unspoiled. will ultimately be needed for effective and While "relatively" may be an appropriate long-term management. However, it does not word, we do have spectacular evidence of have immediate or even medium-term rele- changes and damage to these bird popula- vance to the urgent problems of conservation tions. The use of the Aleutian Islands for fox that now face. What we do need to do is to we farming seems to me a quite horrifying situa- set up some long-term studies of a few care- tion. We know also that the early whalers and selected preferably long-lived fully species— sealers exploited seabird populations. Al- species— so that we can trace the effect of en- though I know of little specific information fluctuations on their perfor- vironmental about the effects of such exploitation on birds for long period. mance a in the northern North Pacific, D. G. Ainley in his survey of historical records from the Vulnerability of the Farallon Islands has shown very clearly the Resource massive effects of human exploitation of birds, starting early in the 19th century. In already understand a number of factors We our area of discussion alone, one species (the that make some of these bird populations par- spectacled cormorant) is extinct and another ticularly vulnerable to the kind of human ac- (the short-tailed albatross) became virtually tivities which we can envisage in the next extinct and is still very rare. I believe that one or two. Most of the breeding birds con- decade or two southern hemisphere species, which on islands where they are vulnerable centrate must have been substantial elements in the predators to disturbance. Many to and human northern summer bird population, have also of them concentrate in flocks on human fish- been seriously depleted as a result of human ing grounds and over other areas of the conti- activity on their breeding grounds. shelf are likely to be the focus of nental which Several speakers emphasized the impor- activity in the near future. In particu- human tance of long-term fluctuations in bird popula- lar, of the birds are known to concen- some tions resulting from natural causes, including in the passes through the Aleutian Is- trate some examples from the North Pacific. Other lands, where they will be particularly vulner- types of human activity must also have had able to future oil spills. In all these ways the some indirect effects on the birds. For concentrated in areas where they are birds are example, whaling and sealing in the 19th cen- disproportionate impacts likely to receive tury must have provided large amounts of activity exploitation. from human and food for scavenging birds and eliminated im- mentioned in One point that has been barely portant competitors for the larger fish-eating this symposium is the effect of molting on the birds. A similar experiment is now in progress of these populations. vulnerability of some as the predatory fish are being overfished. The eiders, for example, concentrate on molting grounds in the Arctic. The exact location the of these molting grounds may not be fully Major Threats to known, but we certainly know that the birds Bird Populations molt somewhere in an area where they will be vulnerable to oil spills (and also to human We now know enough about the distribu-

hunting if the people who move to the Arctic tion and ecology of the seabirds to identify choose to hunt them). Nor are eiders the only the major threats to them that are likely to be species that are flightless when they molt. posed by the projected increase in human ac- Some alcids and loons are also flightless for tivity in the coming decades. The relative im- short periods and, hence, particularly vulner- portance of these threats clearly varies from able to oil spills during molt. species to species and from area to area. How- 310 I. C. T. NISBET

ever, I think that few of us would disagree chemicals, at least in the northern hemi- that the largest single threat in the area as a sphere, and their impact will probably not be whole is posed by oil, not only by the prospect allowed to get worse. of large-scale drilling for oil on the Alaskan Human disturbance is obviously going to continental shelf but also by prospective get very much worse, both from the influx of spills during transportation and deliberate new human populations who will be involved dumping from ships. in more industrialized activities in Alaska and My guess is that the second most important from the likely increase in tourism. A matter threat to the seabirds of the northern North of particular concern is the prospective influx Pacific is the presence of introduced preda- of natural history tours, which can have tors, especially foxes and rats, at the breeding major adverse effects if not carefully colonies. Much of the damage inflicted by regulated. these predators may already have been done, Finally, we should not forget the impact of but I think their continuing presence is likely natural phenomena, including climatic to have as great a negative effect on the bird changes and vulcanism. Bearing in mind the populations as anything else discussed at the experience of Katmai, we might expect a natu- conference. ral disaster to strike a major bird colony at The relative importance of the other identi- any moment. fiable threats to the birds is even more conjec- tural. Drowning of diving birds in fishnets is Practicability of Conservation obviously of great potential impact, but its importance depends greatly on the rapidly Experience from other countries, as related changing practices of fishermen. This problem in various papers at this conference, has must be kept under close surveillance, and the shown that conservation of seabirds is pos- establishment and enforcement of interna- sible and practicable, even in remote and inac- tional agreements will be critical. cessible areas. We have heard today particu- Mineral development has not been men- larly about conservation programs and tioned much. It is my understanding that achievements in Europe and New Zealand. there are prospects for substantial onshore, W. H. Drury spoke briefly about experience in and perhaps offshore, developments of heavy eastern North America and F. Salomonsen metal minerals. These are likely to lead to told us how the bird populations of the local disturbance in the coastal zone, and the Faeroes Islands have been managed for sus- tailings in particular may well pose a threat to tained yield. coastal and inshore birds. At least in the North Atlantic, where the Ocean dumping has not been mentioned. I history of the bird populations is much better do not expect that there will be much dump- known, the conservation situation has been, ing of toxic chemicals from Alaskan indus- and probably still is, very much worse than tries, but we must remember that this area is that now prevailing in the North Pacific. downstream from Japan and the Soviet Looking back on 200 years in the North At-

Union. I do not know the current practices of lantic, we find that two major marine species these countries, but the unregulated dumping have been extinguished, at least one and prob- of toxic substances from some European ably two or three others became endangered, countries apparently has led to large-scale and almost all the seabirds were drastically pollution problems in the North Atlantic. reduced in numbers (at least in temperate lati- On present evidence, persistent pesticides tudes). Starting in the late 19th century when and polychlorinated biphenyls (PCB's) do not many species first received effective protec- seem to pose a significant threat to north tion, most showed impressive recoveries, but Pacific seabirds, although high levels of some have declined again in the last 30 years. PCB's have been reported in shearwaters off We can learn several lessons from that ex- the California coast. In my judgment, we have perience. One is that we can do great damage probably turned the corner in regulating these to seabird populations in a very short time if SYMPOSIUM SUMMARY 311 we do things that cause substantial adult Conservation Needs for mortality. A second is that seabird popula- North Pacific Seabirds tions can recover well with protection and modest management—although most of We now know enough about the seabirds of them, being slow breeders, recover slowly. A the northern North Pacific to specify in prin- third lesson is that in the last 30 years we ciple what should be done immediately to con- have caused substantial damage through oil serve them. I will not address the institu- spills, human disturbance at the breeding tional arrangements needed for conservation; colonies, chemical pollution, and indirectly by R. E. LeResche's paper presented a very clear promoting the spread of gulls. Much has been picture of the institutional problems involved said at the conference about these present- in protecting and managing seabirds on an in- day human impacts. However, with the sole terregional and international basis. I will exception of the oil spills which have affected simply endorse his principal recommendation: alcids and sea ducks in parts of northwest that we should try to bring the various re- it seems to me that the damage Europe, sponsible agencies together to formulate com- human activity in the past 30 years caused by prehensive management plans. considerably less than that in the last 30 is On the level at which we as individuals and years of the 19th century. as a group of biologists can work, we can al- lesson can learn from the recent Another we ready make some positive recommendations. experience in other areas is that it is possible The most important is that since prevention to ameliorate some of these adverse human of damage is a lot better than cure, measures impacts with local, small-scale, and even to avert damage should have the highest rather amateurish management activities— priority. We have heard a great deal from the for example, protecting seabird colonies from oil industry about the "inevitability" of acci- gulls, regulating human visits, and control- dents. One speaker mentioned the "inherent the use of the most toxic chemicals. Our Ung faUibiUty of man." Well, we are all fallible, but conspicuous failure is in controlling oil most the experience of the last 50 years is that Although safety precautions im- pollution. some people are more falUble than others. No posed on offshore drilling rigs and at shipping oil company has a perfect record, but some have proved reasonably effective in terminals have 10 times as many accidents as the best, averting major damage to seabirds, attempts and some, I believe, have considerably more oil pollution during transportation to control than 10 times as many. This means, very have been essentially fruitless. Tanker acci- simply, that it is possible to eUminate most— dents and deliberate discharges from vessels not all, but most— of the major threats to the the major threat to seabird remain seabirds, merely by upgrading the safety per- populations. formance of the entire industry to that al- Another lesson from other areas is that pub- ready achieved by its best segments. I sug- lic has been very effective in put- education gest that our major challenge in the coming ting pressure behind conservation measures, years is to work for effective regulation of the is so increasingly. At the same and doing industry: to achieve regulations which will de- resulting in an increase of time, however, it is cisively penalize bad performance and as deci- the disturbances that the birds suffer at their sively reward care. from casual visitors, breeding grounds Perhaps the second priority in conservation photographers, and sometimes, well-meaning is to protect and manage the existing breed- naturalists. ing colonies. In most cases protection is of the Finally, in very recent years, there have legally feasible if we have the will. Most been encouraging developments in rehabili- major colonies are in remote areas or in public dis- tating oiled birds, captive breeding, and rein- ownership where development and troduction into areas from which they have turbance can be controlled. Management of been depleted. Restoration of seabird popula- the breeding populations is less straightfor- know tions no longer seems an impossible goal. ward, however, because we do not 312 I. C. T. NISBET

enough about the functioning of this complex grams that a few hundred birds, or even a few biological resource. Seabird populations fluc- dozen if properly managed, can be of immense tuate and they have a very long response educational importance. If human access is time, the environment is not constant, we do carefully managed so that people can see the not understand the dynamics of multispecies birds without disturbing them, these pro- communities, and we do not know how they grams can generate support for conservation respond either to external changes or to our of larger bird populations that may be thou- attempts to manage them. Management will sands of miles away where people may never have to be improvisatory for a very long time. see them. We must recognize that effective conservation of a bird population with a 20-year generation time will take at least 20 years to A Rationale for show results. Conservation Another priority task is to control predators. I have been impressed by the evidence As I have tried to show, we know something we have for major effects of predators on the about the importance of this biological re- seabird populations here. I would regard con- source, and we know in outhne what we trol of predators and management of habitats should do to conserve it. But why should we? on some of the major seabird islands as an ex- Almost no one knows the birds are there. We tremely urgent task. ourselves do not know whether there are 50 A longer-term but no less important pro- million or 250 milHon birds in the north gram is public education. This program has Pacific Ocean. Who cares if 10 milhon disap- several important aspects: one is to increase pear? If we cannot give a good answer to this public support for political actions and effec- question, we might as well go home and study tive regulations to protect seabirds; another chickadees instead. is to educate the public about the vulner- To justify spending money on conserving abihty of seabirds and to prevent disturbance marine birds— or any other natural re- or deliberate human destruction. sources—we must establish their value. Some Another aspect of public education is to de- of the arguments made in this conference for velop public interest by making some of the assigning economic values to seabirds have birds more visible. The great problem with been dangerously weak. The annual value of this biological resource we have been talking "muttonbirds" (Puffinus tenuirostris) in the about is that no one knows it is there. Prob- New Zealand markets is about $70,000. Some ably half of us did not know how substantial speakers have tried to argue that seabirds and important a resource it is even 5 years might play some subtle role that we do not yet ago. In setting up a large-scale conservation understand in regulating marine communi- program, we should not make the mistake of ties—perhaps they weed out the sick fish. The basing it only on the most remote and inacces- direct economic values that we have specified sible colonies, even if these are the most im- for seabirds are really not very impressive, portant numerically. Many of the smaller even in terms of the costs involved in conserv- colonies are locally very important, both bio- ing and studying them. The biggest number logically and for human interest and educa- we have heard for the value of these seabirds tion. One example given at this conference is the amount of money we are spending on was the State of Washington's program for surveys. conserving what are, by northern Pacific However, this is not the real issue. In judg- standards, quite small colonies. This program ing the costs and benefits of a conservation is important and impressive because it is con- program, we should not look just at the value serving bird populations near people who of the birds as meat, or oil, or indicators of want to see the birds. We have the same sort pollution. The real issue here, as in all eco- of situation in Massachusetts and Maine, nomic problems, is the rational allocation of where effective protection programs have resources. H. Boyd posed the rhetorical ques- been established for extremely small seabird tion: "Why should we waste public money on colonies. We have learned from these pro- conserving birds when there are so many SYMPOSIUM SUMMARY 313

other things to spend it on?" The question is modify critical habitat. more properly posed in reverse: "Why should These references are not only to Federal the government waste so much public money laws passed by remote politicians who can on unproductive projects when only a small vote with only a modest responsibility to their amount of money can achieve conservation of constituents. As we have heard, there are these birds which some people think are many State laws and local ordinances which important?" specify the same kind of thing. All these laws The fact is that we already know why we are on the books for a powerful reason: public should allocate resources to conservation. I opinion was behind them. The fact that they believe that we have just been evading the have not been enforced and implemented fully answer. We ought to conserve these birds be- means that we have not been doing our job. cause many people want them to be con- In fact, there is no philosophical problem in served. justifying conservation. What we face is an in- This is not, as one speaker said, an elite institutional problem. There is both a public de- terest. The public, as we well know, is already termination that natural resources should be willing to spend money to conserve natural re- conserved and a public apathy and bureau- sources and is increasingly demonstrating cratic resistance toward doing it. As con- that willingness. The public, in fact, is ahead cerned biologists, we should be combating of the administrators and bureaucrats. To ap- this apathy by pointing out that conservation preciate this, we need only look at some of the represents a rational allocation of public laws already on the books. The Congress of resources. the United States, in the National Environ- Those who do not learn the lessons of his- mental Policy Act of 1969, declared that it tory are destined to repeat it. If we study the was the national policy to "create and main- history of conservation, we find that it de- tain conditions under which man and nature veloped most rapidly in those countries which can exist in productive harmony, and fulfill mismanaged their natural resources earliest. the social, economic, and other requirements Within the developed countries there has been of present and future generations of Ameri- a progressive historical trend toward rational cans." The Marine Mammal Protection Act of use and conservation of natural resources. 1972 found that "marine mammals have Conservation of natural resources, in fact, proven themselves to be resources of great in- represents the future and, as biologists, it is ternational significance, esthetic and recrea- our duty to promote it. tional as well as economic, and it is the sense of Congress that they should be protected and Economic Feasibility of encouraged to the greatest extent feasible Conservation commensurate with sound policies of resource management and that the primary object of Conservation is cheap. Most of us are accus- their management should be to maintain the tomed to working on what are essentially health and stability of the marine ecosys- shoestring budgets—on the order of $100,000, tem." As these laws have been enacted, their $10,000, or even $1,000 per year. When we language has become progressively stronger. hear of a million dollars as the cost of doing The Endangered Species Act of 1973 declares something, we tend to think of it as a lot of as the policy of Congress "that all federal de- money. H. Boyd mentioned a situation on partments and agencies shall seek to conserve Baffin Island, where it would cost about a mil- endangered species and threatened species lion dollars to dispose of mine tailings on and shall use their authorities in furtherance shore instead of dumping them into the ocean of the purposes of this Act" (P.L. 93-205). It under a fulmar colony. I do not think a million further directs all Federal departments and dollars is very much—certainly not in com- agencies to carry out conservation programs parison with the cost of restoring a colony of for the conservation of endangered or half a million fulmars. threatened species and to insure that their ac- We heard this morning about the acquisi- tions do not jeopardize the continued tion of Protection Island at a cost of several existence of these species or destroy or hundred thousand dollars. It was pointed out 314 I.C.T.NISBET

that it could have been acquired much more Conclusions cheaply only a few years ago. Acquisition of habitat is cheap if we do it now compared with Practical conservation is an adaptive pro- what it will cost in a few years or a few cess. It is not at present a process that is decades. Management is cheap. None of us firmly based in ecological theory. It is one in gets paid very much, but each of us could which we have to start by doing something, manage several colonies with a couple of stu- see whether it works, and then change our dents to help us. Wardens are cheap. Surveys program in accordance with our early experi- are cheap. The cost of conserving seabirds is ence. I do not beUeve that we can wait for de- minuscule in comparison with the amount tailed knowledge of population sizes, or ecol- spent on the exploitation of resources that ogy, or demography, or trophic importance, threatens them, and it is minuscule in relation or any other biological attribute of these birds to the cost of restoring a seabird population before we start conservation and manage- after it has been depleted. ment. As scientists we do, of course, find it in- It is far cheaper to avoid oiling birds than it teresting and important to study these is to rehabihtate them and to reestablish them things. We should do so; we need to do so; but in breeding colonies in the wild. It costs noth- we should not use our ignorance of detail as an ing at all to award leases to companies that excuse for delaying action. If this seabird re- have a good safety record and to refuse leases source is worth conserving, we should start to companies with bad records. It costs a Uttle now. more to maintain good safety practices in drilling and transportation. It does cost more to transport oil in small, double-bottomed Summary tankers with well-trained crews than to trans-

port it in big ships flying flags of convenience, The marine birds of the northern North but the cost differential is very small com- Pacific Ocean, Bering Sea, and adjacent seas pared to the value of the shipment. constitute one of the great neglected biologi- In considering the economics of conserva- cal resources of the world. tion, we have to weigh the costs of conserva- This resource is impressive in terms of both tion against the value of the resource being total numbers (probably of the order of 100 exploited. Full-scale development of oil re- milUon birds) and species diversity. A number serves on the Alaskan continental shelf would of species are endemic to the area and hence of generate economic values on the order of ten special interest. billion dollars per year. Of this total, 0.1% The resource is international in that it in- would support a reasonably sized manage- cludes major populations of migrants from ment program for the threatened resources. Chile, New Zealand, Australia, Japan, the About 1% of the total, or 12

~~pubUc demand for it. productivity. Hence they are especially vul- SYMPOSIUM SUMMARY 315~~

nerable to human exploitation. lected breeding colonies, including precise Seabirds of the northern Pacific Ocean have photographic surveys that can be used to ab-eady been damaged by human activities in measure future population changes. the past and present. Experience in other • Surveys of the distribution of seabirds of areas shows that seabirds are extremely vul- the North Pacific and Bering Sea in winter, nerable to human activities and their popula- with special emphasis on areas close to shore tions are often very slow to recover. where birds may be vulnerable to oil pollution.

The most important threats to the seabird • Special studies of endemic species. resource are oil drilling and transportation • Studies of the way in which seabirds locate and introduced predators, especially foxes. and use patchily distributed food resources. Other identifiable threats include mineral ex- The following conservation measures are ploitation, fishing, ocean dumping of toxic suggested: chemicals, and human disturbance, including both hunting and tourism. • Adoption of regulations governing exploi- Experience in other parts of the world, espe- tation and transportation of oil which would cially in the North Atlantic, has shown that provide strong incentives for safe per- seabird populations can be protected and re- formance and severe penalties for safety stored through modest programs of manage- violations. ment and public education. The principal ex- • A conservation tax of a few cents per ception has been the failure to regulate dis- barrel of oil to cover the costs of managing the charges of oil at sea, which continue to cause major seabird colonies and to establish a trust major damage to seabird populations in many fund for restoring depleted populations. areas. • Equivalent measures for mining and other In the North Pacific and Bering Sea areas, exploitative industries in the coastal zone the most urgent conservation needs are effec- with a prospective impact on marine tive regulation of prospective oil exploitation, resources. control of introduced predators, and public • Prohibition of dumping of toxic chemicals education. Regional management plans in biologically productive waters. should be developed. PubUc access to bird • A program to eUminate introduced preda- colonies should be managed carefully to com- tors from the Aleutian Islands and from im- bine protection with public education. portant bird colonies elsewhere. Conservation programs for seabirds can be • Promulgation of effective regulations to justified as a response to increasing public de- protect birds under the Migratory Bird mand for rational management of natural re- Treaty with Japan. sources. Conservation programs are inexpen- • Negotiation of migratory bird treaties sive in relation to the economic values gener- with other affected countries, including the ated by oil and mineral development. They Soviet Union, Australia, New Zealand, and represent a rational allocation of economic Chile. resources. • Acquisition of major unprotected seabird The following priorities for further study colonies into the national wildlife refuge or are suggested: other federal landholding systems.

• Study of productivity and demography in • Formulation of regional and international a few carefully selected species to provide management plans for localized species, espe- basic life table data that will permit rapid cially endemic species of the Bering Sea. identification of future changes. • Regulation of public access to major sea- • A base-line census of some carefully se- bird colonies.

~~APPENDIX~~

~~APPENDIX 319~~

~~Papers and Oral Summaries Presented at the Symposium but Which Do Not Appear in this Publication~~

Conservation of marine birds of northern Summary of the session "The Biology and North America— the symposium theme, by Ecology of Marine Birds in the North," by Nathaniel P. Reed Hugh Boyd The marine environment of birds: an over- Summary of the session "Conflicts Between view, by N. PhiUp Ashmole the Conservation of Marine Birds and Uses Environmental hazards to birds from petro- of Other Resources," by Joseph P. Lin- leum development in the Beaufort Sea, by duska Kees Vermeer [in lieu of a paper on the Programs and authorities of the United status of birds in the Beaufort Sea] States Government related to marine bird Birds of the marine habitat off northwestern conservation, by Omar Halvorson North America, by Gerald A. Sanger and Programs and authorities related to marine James G. King bird conservation: Canadian Government, The pelagic and nearshore birds of the Beau- by Hugh Boyd fort and Chukchi Seas, by George J. Divoky Programs and authorities of the State of and George E. Watson Alaska related to marine bird conservation, Dispersal and migratory movements, by by Robert E. LeResche George E. Watson, George M. Jonkel, and Seabird programs of private organizations, by F. Graham Cooch C. Eugene Knoder Summary of the session "Status of Marine Summary of the session "Programs and Bird Populations," by David N. Nettleship Authorities Related to Marine Bird Conser- Breeding habitat of marine birds, by Gerald vation," by William H. Drury A. Bertrand Conservation of marine birds in Antarctica, Exposure of marine birds to environmental by WilUam J. L. Sladen pollutants, by Harry M. Ohlendorf, Robert Seabirds and their conservation in Western W. Risebrough, and Kees Vermeer' Europe, by W. R. P. Bourne Summary of the session, "Conservation of

~~'This paper, because of its length, was published Marine Birds in Other Lands," by Joseph J. separately as Wildlife Research Report 9. Hickey~~

~~,"rU.S GOVERNMENT PRINTING OFFICE: 1979—681-016/29~~

~~"Ty ^49.47/41.11 Gov t. Docs. I~~

~~birds roncrprvation of marine r^'Sfnorthern North America W^f Govt. Docs. I 49.47/4: 1~~

~~Conservation of marine birds of northern North America~~

LUCY SCRIBNER LIBRARY SKIDMORE COLLEGE SARATOGA SPRINGS, N. Y As the Nation's principal conservation agency, the Department of the Interior has responsibility for most of our nationally owned public lands and natural resources. This includes fostering the wisest use of our land and water resources, protecting our fish and wildlife, preserving the environmental and cultural values of our national parks and historical places, and providing for the enjoyment of life through outdoor recreation. The Department as.sesses our energy and mineral resources and works to assure that their development is in the best interests of all our people. The Department also has a major resi)onsi- bility for American Indian reservation communities and for people who live in island territories under U.S. administration.

~~UNITED STATES DEPARTMENT OF THE INTERIOR FISH AND WiLDLIFE SERVICE POSTAGE AND FEES PAID U.S. DEPARTMENT OF THE INTERIOR EDITORIAL OFFICE AYLESWORTH HALL, CSU INT 423 FORT COLLINS, COLORADO 80823~~

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