Fisheries and Wildlife Research 1982 Activities in the Divisions of Research for the Fiscal Year 1982 Edited by Paul H. Eschmeyer, Fisheries Thomas G. Scott, Wildlife Published by the U.S. Fish and Wildlife Service Printed by the U.S. Government Printing Office Denver, Colorado • 1983 •• , :e. ' • Noel Snyder, field biologist for the U.S. Fish and Wildlife Service, Condor Research Center, carries a travel case containing a California condor chick from the chick's nesting site northeast of Los Angeles. The bird was captured in August, after biologists determined that the parents were not feeding the chick regularly. The chick was taken to the San Diego Wild Animal Park to begin a captive breeding program for this critically endangered species. Dr. Phil Ensley, veterinarian for the Zoological Society of San Diego, accompanied Dr. Snyder on the capture operation. Photo by H. K. Snyder. 11 Contents Foreword ...................................................... iv Tunison Laboratory of Fish Nutrition ........ 86 Fisheries and Wildlife Research .............. 1 National Reservoir Research Program . 88 Animal Damage Control ............................ 2 East Central Reservoir Investigations . 89 Denver Wildlife Research Center ............ 2 Multi-Outlet Reservoir Studies .................. 91 Southeast Reservoir Investigations .......... 93 Environmental Contaminant Evaluation 25 White River Reservoir Studies .................... 95 Columbia National Fisheries Research Seattle National Fishery Research Laboratory ............................................... 25 Center ........................................................ 95 Patuxent Wildlife Research Center ........ 38 Migratory Birds .......................................... 100 Endangered Species .................................. 49 Migratory Bird and Habitat Research Patuxent Wildlife Research Center ......... 49 Laboratory .............................................. 100 Great Lake Fisheries ................................. 55 National Wildlife Health Laboratory ...... 105 Great Lakes Fishery Laboratory .............. 55 Northern Prairie Wildlife Research Inland Fisheries and Reservoir Center ...................................................... 110 Management ............................................ 63 Mammals and Nonmigratory Birds .......... 117 Gainesville National Fishery Research Denver Wildlife Research Center ............ 117 Laboratory ............................................... 63 Cooperative Research Unit Program .. 127 La Crosse National Fishery Research Cooperative Fishery Research Units .. 128 Laboratory ............................................... 64 Cooperative Wildlife Research Units .. 145 Leetown National Fisheries Center ........ 73 Cooperative Fishery and Wildlife Fish Farming Experimental Station ........ 75 Research Units ...................................... 170 National Fish Health Research Laboratory ............................................... 77 Publications ................................................ 175 National Fishery Research and Directory ...................................................... 200 Development Laboratory ....................... 81 Southeastern Fish Cultural Laboratory ... 82 Species Index .............................................. 202 Reference to trade names does not imply Government endorsement of commercial products. 111 Foreword A primary goal of the U.S. Fish and Wildlife Service is the conserva- tion and sound management of sport fishery and wildlife resources for the benefit of present and future generations of Americans. Attainment of this goal requires the continual collection, analysis, and synthesis of new information on which wise and timely manage- ment decisions can be based. The Divisions of Research address the principal informational needs of the various management programs of the Service and provide many of the findings that contribute to the accomplishment of the Service's mission. This summary of the activities of the Research Divisions during the fiscal year 1982 (October 1, 1981-September 30, 1982) provides an overview of the nature and scope of research completed and directs attention to the results that should be of significance in the management of fish and wildlife. A substantial portion of the research recounted here concerns cooperative studies between Service scientists and those of other Federal agencies, universities, State agencies, and other countries. We thank the many collaborators for their most valued assistance in advancing the Service's diverse research program. iv Fisheries and Wildlife Research Research responsibilities within the Fish and by talks and lectures, workshops, processed reports, Wildlife Service were carried out by the Division and articles in popular and technical publications. of Wildlife Ecology-Research, the Division of A list of publications is provided in this report. Fishery Ecology-Research, and the Office of Co- During the fiscal year, research was carried out operative Units. During fiscal year 1982, these or- at 12 major facilities, approximately 80 satellite field ganizational entities and their field components con- stations, and 50 Cooperative Research Units under tinued to serve as the fact-finding arm of the Serv- the following programs: Environmental Contami- ice. Information about species of fish and wildlife, nant Evaluation, Biological Services, Migratory the environments required for their existence, and Birds, Mammals and Non-migratory Birds, Animal the effects of management practices on them help Damage Control, Interpretation and Recreation, the U.S. Fish and Wildlife Service and other gov- Fishery Resources, Endangered Species, and ernmental agencies to meet their responsibilities for Cooperative Units. The planning, coordination, and conserving and managing the Nation's fish and administration of the research programs are cen- wildlife for social, economic, aesthetic, and scien- tralized under the Office of the Associate Director- tific benefits. In fulfilling the Service's responsibili- Research in Washington, D.C. Fiscal, personnel, ties, Research cooperates with agencies of the De- property management, and other supporting ser- partments of the Interior, Agriculture, Defense, and vices are provided to the field research facilities by Health, Education, and Welfare; the Atomic Energy the seven Regional Offices of the Service. By the Commission; the Agency for International Develop- end of fiscal year 1982, Research had 751 full-time ment; the Environmental Protection Agency; and permanent employees. The budget included approx- various State agencies, institutions, and private or- imately $36 million of appropriated funds and ganizations. Completed research is communicated $7 million of other funds. 1 Animal Damage Control DENVER WILDLIFE RESEARCH CENTER second-year and older birds; males consumed more corn and sunflower seeds than females, but females consumed more weed seeds, especially foxtail. From Sunflower Fields Protected from Blackbirds by 9 September to 6 October foxtail seeds made up 4-Aminopyridine Baits. In 1981, 4-aminopyridine 37% of the male and 75% of the female diets. Use baits, applied by hand in 20-foot swaths from bait- of sunflower seeds by redwings was highest between ing lanes, were evaluated for protecting ripening 26 August and 6 October (the major sunflower sunflowers from blackbird damage in six test fields damage season), when 71% of the male and 57% in Ramsey and Benson counties, North Dakota. A of the female diets were sunflowers. split-field design (two experimental units separated Redwings collected for food studies were also by a buffer unit) and a 12-day test period (6 days examined for phenology of molt (N = 3,795). pretreatment and 6 days treatment) were used. Second-year males were found molting in the sec- In test fields with paired experimental units, un- ond week of July, 1 week earlier than older males. treated units lost 10,806 pounds of sunflower seed After-hatching-year (AHY) females began molting to birds during the 6-day treatment period, whereas the third week of July; by the last week of Septem- baited units lost 5,143 pounds of seed, or 52% less. ber some of these had completed molt. Hatching- However, untreated units also had more damage year birds likewise began to molt in the third week during pretreatment periods and the adjusted losses of July, but some of these birds had not completed on baited units were 43.6% less than expected dur- molt until the first week of October. ing the baiting period. Start of molt among AHY birds may be related Peak numbers of blackbirds damaging test fields to nesting activities. Second-year males, generally ranged from 5,000 to 31,000 on individual fields nonbreeding, began to molt first, whereas breed- during the test period. The species composition of ing males tended to leave their territories before the feeding flocks was estimated to be 73% red-winged females completed nesting. Breeding males also blackbirds, 20% yellow-headed blackbirds, and 7% molted earlier than females. Molt progress indicates common grackles. The estimated kill of 169 black- that by late September most of the local redwings birds was similar in composition. However, 30 of have migrated and birds remaining in southwest- 34 birds seen giving distress displays were yel- ern Cass County during October are transients. low-headed blackbirds. We found evidence that The food habits findings point to some useful many redwings broke the chopped corn baits