DOCSLIB.ORG

The Kleotoparasitic Interactions Between Great Frigatebirds And

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

The Condor 96:331-340 0 The CooperOmithological Society 1994 THE KLEPTOPARASITIC INTERACTIONS BETWEEN GREAT FRIGATEBIRDS AND MASKED BOOBIES ON HENDERSON ISLAND, SOUTH PACIFIC ’ J. A. VICKERY2 Universityof East Anglia, Schoolof Biological Sciences,Norwich, NR4 7TJ, U.K. M. DE L. BROOKE Department of Zoology, Cambridge University,Downing Street, Cambridge,CB2 3EJ, U.K. Abstract. Kleptoparasitic activities by Great Frigatebirds (Fregata minor) on Masked Boobies (Sula dactylatru) were quantified on Henderson Island in the South Pacific. The frequency of kleptoparasitic attacks increased towards dusk, the time when most Masked Boobiesreturned to the roost site. Masked Boobiesreturning to the roost low (i 30 m) over the water were significantlymore likely to be chasedthan thosereturning at a higher altitude. Single boobies were also significantly more likely to be attacked than boobies returning as one of a group of birds. However, group size and height were positively correlated. There was no effect of group size on the likelihood of attack. Sixteen percent of chases were successfuland the successrate was not influenced by either the height or the distance of the target from the roost. The duration of the chase was, however, influenced by the position of the target: chases on distant or high targets lasted significantly longer than chaseson targetsthat were low or close to the roost. In addition successfulchases were significantly longer than unsuccessfulones. We discussthese results in relation to the chase tactics of frigatebirds, the avoidance tactics of boobies and the energetic costs and benefits of klep- toparasitism. Approximately 40% of daily energy expenditure of some individual Great Frigatebirds may be securedthrough kleptoparasitism. However, on average, frigatebirds may be meeting under five percent of their daily energy demands by this feeding method. Key words: Boobies;chase duration; energeticxfrigatebirds; kleptoparasitism; Pa& Ocean. INTRODUCTION and has been well studied in the latter three (e.g., Kleptoparasitism, the stealing by one animal of Dunn 1973, Anderson 1976, Verbeek 1977, Bur- food which has already been caught by another, ger 198 1, Fumess and Hislop 1981, Birt and occurswidely throughout the animal kingdom in Cairns 1987). However, despite the fact that frig- a range of taxonomic groups including insects, atebirds are considered among the most spe- fish, reptiles, birds and mammals (Thompson cialized kleptoparasites (Fumess 1987), few de- 1986). Although kleptoparasitismmay reducethe tailed studies of the interactions between costs of foraging, by using the time and energy frigatebirds and their hosts exist (Fumess 1987, investment of others, it involves a high degree Osomo et al. 1992). of specialization and is likely to be profitable only The aims of this study were to carry out a under certain ecologicalconditions, for example, detailed study of the kleptoparasitic behavior of where numerous potential hosts carry large the Great Frigatebird (Fregata minor) on one of quantities of food and behave in a predictable its main target species,the Masked Booby (Sula way (Brockmann and Barnard 1979). dactylatru) and to evaluate the importance of this Kleptoparasitism is an important feeding feeding method in satisfying the energy needs of method in four seabird families; Fregatidae (frig- the frigatebirds. Data are presented on the daily atebirds), Chionididae (sheathbills), Ster- activity pattern of Great Frigatebirds and Masked corariidae (skuas) and Laridae (gulls and terns) Boobies over inshore waters around Henderson Island, South Pacific;the nature of the flight paths adopted by Masked Boobies as they return to I Received1 September 1993. Accepted 10 January their roost site; the location, duration and out- 1994. come of kleptoparasitic attacks;and the number, * Present address: Division of Biological Sciences, size, and species of fish that may be obtained University of Edinburgh, Ashworth Laboratories, Ring’s Buildings, West Mains Road, Edinburgh EH9 from a successfulattack. This information is then 3JT. used, in conjunction with published figures for [3311 332 J. A. VICKERY AND M. DE L. BROOKE metabolic costsof flight and energy values of fish, came into view. Any time during which no in- to assessthe proportion of the daily energy re- dividuals were present was recorded. quirements of Great Frigatebirds that may be obtained from kleptoparasitism. FLIGHT PATHS OF MASKED BOOBIES RETURNING TO THE ROOST SITE STUDY AREA AND METHODS Detailed observations were made of the flight The study was carried from April to June 199 1, paths of Masked Boobies returning to the roost on Henderson Island (24”22’S, 128”2O’W), one site during ten 2-hr watches at dusk (16:00 to of the Pitcairn Islands in the South Pacific. Hen- 18:00 hr). Individual Masked Boobies were derson is a raised coral atoll with limestone cliffs sighted up to 600 m offshore and followed until reaching 34 m above sealevel, a fringing reef 50- they had either landed at the roost site or were 100 m wide and three beaches;one on each of lost from view out to sea. For each individual the north, west and east coasts(Fig. 1). The East bird the following information was recorded: (i) Beach was approximately 2 km long with a 20- whether the booby was single or one of a group 30 m wide strip of vegetation, primarily Pan- and the size of the group, (ii) the height at which danus tectorius and Argusia argentea, between the booby crossedthe reef (estimated to the near- the beach and the base of the cliffs. During the est 5 m in relation to the height of the cliff) and study period, 70 to 80 Masked Boobies roosted (iii) whether it was chasedand, if so, whether the at the base of the cliffs on East Beach. The roost chasewas successful(a chasewas consideredsuc- site was located in a natural clearing on the sea- cessfulif the booby was forced to regurgitateand ward edge of the beach vegetation. All obser- the frigatebird obtained the food). The same in- vations of frigatebirds and boobies were made formation was recorded for the small number of from a position on the edgeof the vegetation 150 Red-footed Boobies (Sula sula) that were also m south of the roost. seen crossingEast Beach to roost further inland. A maximum of 126 Great Frigatebirds was recordedover East Beachduring the study period KLEPTOPARASITIC BEHAVIOR OF GREAT FRIGATEBIRDS (pers. observ.). Frigatebirds on Henderson nest- ed and roosted in the forest of the interior pla- Individual frigatebirds were followed during ten teau. Following laying in June, the number of 2-hr watches at dusk (16:00 to 18:00 hr). For frigatebirds continued low, probably under 100 each kleptoparasitic attack the following infor- pairs. mation was recorded: (i) the time at the start of the chase (taken as the moment the frigatebird DAILY ACTIVITY PATTERN OF GREAT switched from gliding to direct flapping flight FRIGATEBIRDS AND MASKED BOOBIES towards the booby, (ii) the distance or initial lo- The numbers of Masked Boobies returning to cation of the target booby from the roost site roost and the activity of frigatebirds were re- (identified as being in one of three zones: over corded during five watches from 06:OOto 18:OO the beach, between the reef and the beach or hr and five additional 2-hr watches from 16:00- beyond the reel), (iii) the height of the target 18:00 hr (local time = GMT less 8.5 hr). Indi- above the sea or beach, (iv) whether the target vidual frigatebirds were followed using 10 x 40 was single or one of a group, (v) the duration of binoculars and the total time spent perching, the chase, (vi) the outcome of the chase and, if gliding (slow, often circling flight with few or no successful,(vii) the number of fish the frigatebird wing beats) and chasing (rapid, flapping flight) obtained. was recorded during each 2-hr observation pe- Information on sneciesand mass of fish that riod. Individual birds were selected at random were carried by boobies to the roost was obtained and followed constantly until they were lost from from regurgitateswhich usually comprised easily view as they flew either out to sea, around the separated,barely digested fish. Masked Boobies cliffs to the north or south of the beach, or over- will readily regurgitate food if disturbed by peo- head and into the interior of the island. The time ple. Fish were obtained from this sourceand also at which a bird was lost from view was recorded as a result of chaseswhere the frigatebird either and observations were switched to another ran- missedor dropped the regurgitatedfood. The fish domly selectedindividual. This switch was made were identified to family and weighedto the near- immediately or as soon as another individual est 0.5 g using a O-100 g Pesola spring balance. KLEPTOPARASITIC BEHAVIOR OF GREAT FRIGATEBIRDS 333 Pacific Ocean Christmas Island Equator . _____------___-------__--_--_________--------__________ Tahiti a ~_-------__-_--~--~~~--------------------- Oenos+Henderson__________-__________________ Pitcairns Duois . Easter Island 1 New Zealand Henderson Island I- 1Km *Masked Soobv Roost Site FIGURE 1. The study site. RESULTS inshore waters for approximately half of the time (mean = 51.0%, 95% Confidence Intervals [CI] DAILY ACTIVITY PATTERN OF MASKED = 39.1-62.8%, 30 2-hr periods; arcsinetrans- BOOBIES AND GREAT FRIGATEBIRDS n = formations). When visible over theseinshore wa- Throughout the day (06:OO to 18:00 hr) one or ters frigatebirds spent 16.9% (95% CI = 1 l.O- more frigatebirds were visible in the air over 23.9%) of their time perched, 82.0% (95% CI = 334 J. A. VICKERY AND M. DE L. BROOKE u .9 time spent chasing by frigatebirds ki a q time spent perching by frigatebirds 5 c] time spent gliding by frigatebirds _? (a) 0 number of returning boobies 6-8 8-10 10-12 12-14 14-16 16-18 Time of day loo- 80 - 60 - 40 - 1600 1630 1700 1730 1800 Time of day FIGURE 2.
Recommended publications
  • Kendall Birds

    Kendall Birds

    Kendall-Frost Reserve Breeding Common Name Scientific Name Regulatory Status Status Waterfowl - Family Anatidae Brant Branta bernicla W Special Concern Gadwall Ana strepera W American Wigeon Anas americana W Mallard Anas platyrhynchos Y Cinnamon Teal Anas cyanoptera W Northern Shoveler Anas clypeata W Northern Pintail Anas acuta W Green-winged Teal Anas crecca W Redhead Aythya americana W Lesser Scaup Aythya affinis W Bufflehead Bucephala albeola W Red-breasted Merganser Mergus serrator W Ruddy Duck Oxyura jamaicensis W Loons - Family Gaviidae Common Loon Gavia immer W Special Concern Grebes - Family Podicipedidae Pied-billed Grebe Podilymbus podiceps W Horned Grebe Podiceps auritus W Eared Grebe Podiceps nigricollis W Western Grebe Aechmophorus occidentalis W Clark's Grebe Aechmophorus clarkii W Pelicans - Family Pelecanidae Brown Pelican Pelecanus occidentalis Y Endangered Frigatebirds - Family Fregatidae Magnificent Frigatebird Fregata magnificens X Cormorants - Family Phalacrocoracide Double-crested Cormorant Phalacrocorax auritus Y Herons and Bitterns - Family Ardeidae Great Blue Heron Ardea herodias Y Great Egret Ardea alba Y Snowy Egret Egretta thula Y Little Blue Heron Egretta caerulea Y Green Heron Butorides virescens Y Black-crowned Night Heron Nycticorax nycticorax Y Hawks, Kites and Eagles - Family Accipitridae Osprey Pandion haliaetus Y White-tailed Kite Elanus leucurus W Northern Harrier Circus cyaneus W Special Concern Cooper's Hawk Accipiter cooperii Y Red-shouldered Hawk Buteo lineatus Y Red-tailed Hawk Buteo jamaicensis
  • A Guide to the Birds of Barrow Island

    A Guide to the Birds of Barrow Island

    A Guide to the Birds of Barrow Island Operated by Chevron Australia This document has been printed by a Sustainable Green Printer on stock that is certified carbon in joint venture with neutral and is Forestry Stewardship Council (FSC) mix certified, ensuring fibres are sourced from certified and well managed forests. The stock 55% recycled (30% pre consumer, 25% post- Cert no. L2/0011.2010 consumer) and has an ISO 14001 Environmental Certification. ISBN 978-0-9871120-1-9 Gorgon Project Osaka Gas | Tokyo Gas | Chubu Electric Power Chevron’s Policy on Working in Sensitive Areas Protecting the safety and health of people and the environment is a Chevron core value. About the Authors Therefore, we: • Strive to design our facilities and conduct our operations to avoid adverse impacts to human health and to operate in an environmentally sound, reliable and Dr Dorian Moro efficient manner. • Conduct our operations responsibly in all areas, including environments with sensitive Dorian Moro works for Chevron Australia as the Terrestrial Ecologist biological characteristics. in the Australasia Strategic Business Unit. His Bachelor of Science Chevron strives to avoid or reduce significant risks and impacts our projects and (Hons) studies at La Trobe University (Victoria), focused on small operations may pose to sensitive species, habitats and ecosystems. This means that we: mammal communities in coastal areas of Victoria. His PhD (University • Integrate biodiversity into our business decision-making and management through our of Western Australia)
  • Updating the Seabird Fauna of Jakarta Bay, Indonesia

    Updating the Seabird Fauna of Jakarta Bay, Indonesia

    Tirtaningtyas & Yordan: Seabirds of Jakarta Bay, Indonesia, update 11 UPDATING THE SEABIRD FAUNA OF JAKARTA BAY, INDONESIA FRANSISCA N. TIRTANINGTYAS¹ & KHALEB YORDAN² ¹ Burung Laut Indonesia, Depok, East Java 16421, Indonesia ([email protected]) ² Jakarta Birder, Jl. Betung 1/161, Pondok Bambu, East Jakarta 13430, Indonesia Received 17 August 2016, accepted 20 October 2016 ABSTRACT TIRTANINGTYAS, F.N. & YORDAN, K. 2017. Updating the seabird fauna of Jakarta Bay, Indonesia. Marine Ornithology 45: 11–16. Jakarta Bay, with an area of about 490 km2, is located at the edge of the Sunda Straits between Java and Sumatra, positioned on the Java coast between the capes of Tanjung Pasir in the west and Tanjung Karawang in the east. Its marine avifauna has been little studied. The ecology of the area is under threat owing to 1) Jakarta’s Governor Regulation No. 121/2012 zoning the northern coastal area of Jakarta for development through the creation of new islands or reclamation; 2) the condition of Jakarta’s rivers, which are becoming more heavily polluted from increasing domestic and industrial waste flowing into the bay; and 3) other factors such as incidental take. Because of these factors, it is useful to update knowledge of the seabird fauna of Jakarta Bay, part of the East Asian–Australasian Flyway. In 2011–2014 we conducted surveys to quantify seabird occurrence in the area. We identified 18 seabird species, 13 of which were new records for Jakarta Bay; more detailed information is presented for Christmas Island Frigatebird Fregata andrewsi. To better protect Jakarta Bay and its wildlife, regular monitoring is strongly recommended, and such monitoring is best conducted in cooperation with the staff of local government, local people, local non-governmental organization personnel and birdwatchers.
  • MAGNIFICENT FRIGATEBIRD Fregata Magnificens

    MAGNIFICENT FRIGATEBIRD Fregata Magnificens

    PALM BEACH DOLPHIN PROJECT FACT SHEET The Taras Oceanographic Foundation 5905 Stonewood Court - Jupiter, FL 33458 - (561-762-6473) [email protected] MAGNIFICENT FRIGATEBIRD Fregata magnificens CLASS: Aves ORDER: Suliformes FAMILY: Fregatidae GENUS: Fregata SPECIES: magnificens A long-winged, fork-tailed bird of tropical oceans, the Magnificent Frigatebird is an agile flier that snatches food off the surface of the ocean and steals food from other birds. It breeds mostly south of the United States, but wanders northward along the coasts during nonbreeding season. Physical Appearance: Frigate birds are the only seabirds where the male and female look strikingly different. All have pre- dominantly black plumage, long, deeply forked tails and long hooked bills. Females have white underbellies and males have a distinctive red throat pouch, which they inflate during the breeding season to attract females Their wings are long and pointed and can span up to 2.3 meters (7.5 ft), the largest wing area to body weight ratio of any bird. These birds are about 35-45 inches ((89 to 114 cm) in length, and weight between 35 and 67 oz (1000-1900 g). The bones of frigate birds are markedly pneumatic (filled with air), making them very light and contribute only 5% to total body weight. The pectoral girdle (shoulder joint) is strong as its bones are fused. Habitat: Frigate birds are found across all tropical oceans. Breeding habitats include mangrove cays on coral reefs, and decidu- ous trees and bushes on dry islands. Feeding range while breeding includes shallow water within lagoons, coral reefs, and deep ocean out of sight of land.
  • Threats to the Critically Endangered Christmas

    Threats to the Critically Endangered Christmas

    Tirtaningtyas & Hennicke: Threats to the criticallyContributed endangered Papers Christmas Island Frigatebird Fregata andrewsi 137 THREATS TO THE CRITICALLY ENDANGERED CHRISTMAS ISLAND FRIGATEBIRD FREGATA ANDREWSI IN JAKARTA BAY, INDONESIA, AND IMPLICATIONS FOR RECONSIDERING CONSERVATION PRIORITIES FRANSISCA N. TIRTANINGTYAS1 & JANOS C. HENNICKE2,3 1Burung Laut Indonesia, Depok, East Java, 16421, Indonesia ([email protected]) 2Dept. of Ecology and Conservation, University of Hamburg, 20146 Hamburg, Germany 3CEBC-CNRS, 79360 Villiers-en-Bois, France Received 4 November 2014, accepted 26 February 2015 SUMMARY Tirtaningtyas, F.N. & HENNICKE, J.C. 2015. Threats to the critically endangered Christmas Island Frigatebird Fregata andrewsi in Jakarta Bay, Indonesia, and implications for reconsidering conservation priorities. Marine Ornithology 43: 137–140. The Christmas Island Frigatebird Fregata andrewsi is one of the most endangered seabirds in the world. The reasons for its population decline are unknown, but recommended protection measures and management actions focus on the species’ breeding site. Threats to the species away from Christmas Island have received little consideration. Here, we report on several previously undescribed anthropogenic threats to Christmas Island Frigatebirds based on observations in Jakarta Bay, Indonesia: accidental entanglement in fishing gear, as well as capture, poisoning and shooting. Based on these findings, we suggest that it is imperative to reconsider the present management strategies and conservation priorities for the species and to urgently include protection measures away from Christmas Island. Keywords: Christmas Island Frigatebird, Fregata andrewsi, conservation, mortality, anthropogenic threats, Jakarta Bay, Southeast Asia INTRODUCTION Christmas Island Frigatebirds are exposed to threats in Southeast Asian waters, namely in Jakarta Bay, Indonesia, that might contribute The Christmas Island Frigatebird Fregata andrewsi is one of the to the unexplained population decline of the species.
  • Phylogenetic Patterns of Size and Shape of the Nasal Gland Depression in Phalacrocoracidae

    Phylogenetic Patterns of Size and Shape of the Nasal Gland Depression in Phalacrocoracidae

    PHYLOGENETIC PATTERNS OF SIZE AND SHAPE OF THE NASAL GLAND DEPRESSION IN PHALACROCORACIDAE DOUGLAS SIEGEL-CAUSEY Museumof NaturalHistory and Department of Systematicsand Ecology, University of Kansas, Lawrence, Kansas 66045-2454 USA ABSTRACT.--Nasalglands in Pelecaniformesare situatedwithin the orbit in closelyfitting depressions.Generally, the depressionsare bilobedand small,but in Phalacrocoracidaethey are more diversein shapeand size. Cormorants(Phalacrocoracinae) have small depressions typical of the order; shags(Leucocarboninae) have large, single-lobeddepressions that extend almost the entire length of the frontal. In all PhalacrocoracidaeI examined, shape of the nasalgland depressiondid not vary betweenfreshwater and marine populations.A general linear model detectedstrongly significant effectsof speciesidentity and gender on size of the gland depression.The effectof habitat on size was complexand was detectedonly as a higher-ordereffect. Age had no effecton size or shapeof the nasalgland depression.I believe that habitat and diet are proximateeffects. The ultimate factorthat determinessize and shape of the nasalgland within Phalacrocoracidaeis phylogenetichistory. Received 28 February1989, accepted1 August1989. THE FIRSTinvestigations of the nasal glands mon (e.g.Technau 1936, Zaks and Sokolova1961, of water birds indicated that theseglands were Thomson and Morley 1966), and only a few more developed in species living in marine studies have focused on the cranial structure habitats than in species living in freshwater associatedwith the nasal gland (Marpies 1932; habitats (Heinroth and Heinroth 1927, Marpies Bock 1958, 1963; Staaland 1967; Watson and Di- 1932). Schildmacher (1932), Technau (1936), and voky 1971; Lavery 1972). othersshowed that the degree of development Unlike most other birds, Pelecaniformes have among specieswas associatedwith habitat. Lat- nasal glands situated in depressionsfound in er experimental studies (reviewed by Holmes the anteromedialroof of the orbit (Siegel-Cau- and Phillips 1985) established the role of the sey 1988).
  • P0529-P0540.Pdf

    P0529-P0540.Pdf

    RESPONSES TO HIGH TEMPERATURE IN NESTLING DOUBLE-CRESTED AND PELAGIC CORMORANTS ROBERT C. L^$IEWSKI AND GREGORY K. SNYDER ADULTand nestlingcormorants are often subjectto overheatingfrom insolationat the nest. Their generallydark plumage,exposed nest sites, and reradiation from surroundingrocks aggravate the thermal stress. Young nestlingsmust be shieldedfrom the sun by their parents. Older nestlingsand adults compensatefor heat gain throughbehavioral adjust- mentsand modulationof evaporativecooling by pantingand gular flutter- ing. This study was undertakento examinesome of the responsesto high temperaturein nestlingsof two speciesof cormorants,the Double-crested Cormorant,Phalacrocorax auritus, and the PelagicCormorant, P. pelagicus. The evaporative cooling responsesin birds have been studied in some detail in recent years (see Bartholomewet al., 1962; Lasiewski et al., 1966; Bartholomewet al., 1968; Calder and Schmidt-Nielsen,1968, for more detailed discussions),although much still remains to be learned. MATERIALS AND •VIETI-IODS The nestling cormorantsused in this study (four Phalacrocoraxpelagicus and four P. auritus) were captured from nests on rocky islands off the northwest coast of Washington. As their dates of hatchingwere not known it was impossibleto provide exact ages. From comparisonsof feather developmentwith descriptionsin the literature (Bent, 1922; Palmer, 1962), we judged that the pe'lagicuschicks were approximately 5, 5, 6, and 6 weeksold, while'the auritus chickswere 3.5, 3.5, 4.5, and 6 weeksof age upon capture. The nestlingswere taken to the laboratoriesat Friday Harbor, Washington on the day of capture and housed in three 4' X 4' X 4' chicken wire cages. The cageswere equippedwith plywood platforms for the birds to sit on and coveredon top and two sides to shield birds from wind and rain.
  • GREAT FRIGATEBIRD Fregata Minor

    GREAT FRIGATEBIRD Fregata Minor

    GREAT FRIGATEBIRD Fregata minor Other: ‘Iwa F.m. palmerstoni breeding visitor, indigenous Great Frigatebird is nearly a pantropical species, being absent only from the Atlantic Ocean north of the equator (King 1967, Harrison 1983, Marchant and Higgins 1990, Metz and Schreiber 2002). It is a common breeder at Johnston and Wake atolls (Amerson and Shelton 1976, Rauzon et al. 2008). In the Northwestern Islands it breeds in Mar-Oct, it roosts in large numbers on certain islets of the Southeastern Islands, and is a fairly common sight soaring over most islands (although less common over Hawai’i I) throughout the year. POBSP data indicate a slight depression in monthly counts during Nov-Feb, especially in the more northwestern of the islands; when not breeding, it appears to disperse widely throughout tropical and subtropical seas, with vagrants recorded N to California (CBRC 2007), and individuals banded at Kure recovered as far away as the Marshall and Philippine Is (Woodward 1972). Hadden (1941) records a large movement of birds from Midway toward Kure on 29 Dec 1938. A frigatebird, probably Great, is present in the fossil record of Ulupau Head, O'ahu, indicating presence in the islands for at least 200,000 years (James 1987). There was much confusion about the naming of frigatebirds in the 1800s. Early ornithologists in Hawaii (Isenbeck in Kittlitz 1834, Dole 1869, Stejneger 1888, Wilson and Evans 1899, Rothschild 1900) considered the Hawaiian population to be the same species as Ascension Island Frigatebird (F. aquila) of the c. Atlantic Ocean, although Cassin (1858) and Dole (1879) correctly assigned them to "palmerstoni" based on Gmelin's (1789) "Pelecanus palmerstoni" from Palmerston I in the Cook Is group.

  • The Genus Sula in the Carolinas: an Overview of the Phenology And

    h Gn Sl n th Crln: An Ovrv f th hnl nd trbtn f Gnnt nd b n th Sth Atlnt ht DAVID S. LEE and J. CHRISTOPHER HANEY Five of the eight recognized species of the genus Sula are known from the southeastern United States. Of these only the Northern Gannet (Sula bassana) occurs regularly in the Carolinas, but both the Masked Booby (S. dactylatra), formerly Blue- faced, and the Brown Booby (S. leucogaster) have been reported from North and South Carolina. Of the two remaining species, the Red-footed Booby (S. sula) is generally restricted to the Caribbean and disperses northward into the Florida Keys and Gulf of Mexico, whereas the Blue-footed Booby (S. nebouxii) is an eastern Pacific species with one accidental and astonishing record from south Padre Island, Texas (5 October 1976, photograph Amer. Birds 31:349-351). Generally the records for locally occurring Sula, excluding wintering Northern Gannets, are less than adequate as conclusive evidence of seasonal or geographical occurrence. Most problems result from confusing plumages of the various species and the general lack of experience of North American bird students with boobies. An additional problem is the fact that until very recently most ornithologists believed that boobies occurred off the south Atlantic states, outside Florida, only as rare accidentals, causing many records to be viewed with excessive caution and skepticism. Potter et al. (1980), for example, associated all records of boobies in the Carolinas with storms. In recent years few groups of birds have caused as many interpretive problems for the Carolina Bird Club's North Carolina Records Committee as have the Sula.
  • Plumage and Sexual Maturation in the Great Frigatebird Fregata Minor in the Galapagos Islands

    Plumage and Sexual Maturation in the Great Frigatebird Fregata Minor in the Galapagos Islands

    Valle et al.: The Great Frigatebird in the Galapagos Islands 51 PLUMAGE AND SEXUAL MATURATION IN THE GREAT FRIGATEBIRD FREGATA MINOR IN THE GALAPAGOS ISLANDS CARLOS A. VALLE1, TJITTE DE VRIES2 & CECILIA HERNÁNDEZ2 1Universidad San Francisco de Quito, Colegio de Ciencias Biológicas y Ambientales, Campus Cumbayá, Jardines del Este y Avenida Interoceánica (Círculo de Cumbayá), PO Box 17–12–841, Quito, Ecuador ([email protected]) 2Pontificia Universidad Católica del Ecuador, Departamento de Ciencias Biológicas, PO Box 17–01–2184, Quito, Ecuador Received 6 September 2005, accepted 12 August 2006 SUMMARY VALLE, C.A., DE VRIES, T. & HERNÁNDEZ, C. 2006. Plumage and sexual maturation in the Great Frigatebird Fregata minor in the Galapagos Islands. Marine Ornithology 34: 51–59. The adaptive significance of distinctive immature plumages and protracted sexual and plumage maturation in birds remains controversial. This study aimed to establish the pattern of plumage maturation and the age at first breeding in the Great Frigatebird Fregata minor in the Galapagos Islands. We found that Great Frigatebirds attain full adult plumage at eight to nine years for females and 10 to 11 years for males and that they rarely attempted to breed before acquiring full adult plumage. The younger males succeeded only at attracting a mate, and males and females both bred at the age of nine years when their plumage was nearly completely adult. Although sexual maturity was reached as early as nine years, strong competition for nest-sites may further delay first reproduction. We discuss our findings in light of the several hypotheses for explaining delayed plumage maturation in birds, concluding that slow sexual and plumage maturation in the Great Frigatebird, and perhaps among all frigatebirds, may result from moult energetic constraints during the subadult stage.
  • Eastern Australia: October-November 2016

    Eastern Australia: October-November 2016

    Tropical Birding Trip Report Eastern Australia: October-November 2016 A Tropical Birding SET DEPARTURE tour EASTERN AUSTRALIA: From Top to Bottom 23rd October – 11th November 2016 The bird of the trip, the very impressive POWERFUL OWL Tour Leader: Laurie Ross All photos in this report were taken by Laurie Ross/Tropical Birding. 1 www.tropicalbirding.com +1-409-515-9110 [email protected] Page Tropical Birding Trip Report Eastern Australia: October-November 2016 INTRODUCTION The Eastern Australia Set Departure Tour introduces a huge amount of new birds and families to the majority of the group. We started the tour in Cairns in Far North Queensland, where we found ourselves surrounded by multiple habitats from the tidal mudflats of the Cairns Esplanade, the Great Barrier Reef and its sandy cays, lush lowland and highland rainforests of the Atherton Tablelands, and we even made it to the edge of the Outback near Mount Carbine; the next leg of the tour took us south to Southeast Queensland where we spent time in temperate rainforests and wet sclerophyll forests within Lamington National Park. The third, and my favorite leg, of the tour took us down to New South Wales, where we birded a huge variety of new habitats from coastal heathland to rocky shorelines and temperate rainforests in Royal National Park, to the mallee and brigalow of Inland New South Wales. The fourth and final leg of the tour saw us on the beautiful island state of Tasmania, where we found all 13 “Tassie” endemics. We had a huge list of highlights, from finding a roosting Lesser Sooty Owl in Malanda; to finding two roosting Powerful Owls near Brisbane; to having an Albert’s Lyrebird walk out in front of us at O Reilly’s; to seeing the rare and endangered Regent Honeyeaters in the Capertee Valley, and finding the endangered Swift Parrot on Bruny Island, in Tasmania.
  • Checklist of the Birds of Micronesia Peter Pyle and John Engbring for Ornithologists Visiting Micronesia, R.P

    Checklist of the Birds of Micronesia Peter Pyle and John Engbring for Ornithologists Visiting Micronesia, R.P

    ./ /- 'Elepaio, VoL 46, No.6, December 1985. 57 Checklist of the Birds of Micronesia Peter Pyle and John Engbring For ornithologists visiting Micronesia, R.P. Owen's Checklist of the Birds of Micronesia (1977a) has proven a valuable reference for species occurrence among the widely scattered island groups. Since its publication, however, our knowledge of species distribution in Micronesia has been substantially augmented. Numerous species not recorded by Owen in Micronesia or within specific Micronesian island groups have since been reported, and the status of many other species has changed or become better known. This checklist is essentially an updated version of Owen (1977a), listing common and scientific names, and occurrence status and references for all species found in Micronesia as recorded from the island groups. Unlike Owen, who gives the status for each species only for Micronesia as a whole, we give it for -each island group. The checklist is stored on a data base program on file with the U.S. Fish and Wildlife Service (USFWS) in Honolulu, and we encourage comments and new or additional information concerning its contents. A total of 224 species are included, of which 85 currently breed in Micronesia, 3 have become extinct, and 12 have been introduced. Our criteria for-species inclusion is either specimen, photograph, or adequately documented sight record by one or more observer. An additional 13 species (listed in brackets) are included as hypothetical (see below under status symbols). These are potentially occurring species for which reports exist that, in our opinion, fail to meet the above mentioned criteria.