U.S. Geological Survey Migratory Bird Science, 2020–21 Circular 1480 U.S. Department of the Interior U.S. Geological Survey Long-billed curlew. Photograph by Kari Cieszkiewicz, U.S. Fish and Wildlife Service. Front cover. Northern pintails during spring migration. Photograph by Brandon Jones, U.S. Fish and Wildlife Service. Inside front cover. Long-billed curlew. Photograph by Kari Cieszkiewicz, U.S. Fish and Wildlife Service. Facing page. Trumpeter swans at LaCreek National Wildlife Refuge. Photograph by Tom Koerner, U.S. Fish and Wildlife Service. U.S. Geological Survey Migratory Bird Science, 2020–21 Edited by Aaron T. Pearse, Mark H. Sherfy, Mark Wimer, Mona Khalil, and Mark T. Wiltermuth Trumpeter swans at LaCreek National Wildlife Refuge. Photograph by Tom Koerner, U.S. Fish and Wildlife Service. Circular 1480 U.S. Department of the Interior U.S. Geological Survey U.S. Geological Survey, Reston, Virginia: 2021 For more information on the USGS—the Federal source for science about the Earth, its natural and living resources, natural hazards, and the environment—visit https://www.usgs.gov or call 1–888–ASK–USGS. For an overview of USGS information products, including maps, imagery, and publications, visit https://store.usgs.gov/. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Although this information product, for the most part, is in the public domain, it also may contain copyrighted materials as noted in the text. Permission to reproduce copyrighted items must be secured from the copyright owner. Suggested citation: Pearse, A.T., Sherfy, M.H., Wimer, M., Khalil, M., and Wiltermuth, M.T., 2021, U.S. Geological Survey migratory bird science, 2020–21: U.S. Geological Survey Circular 1480, 131 p., https://doi.org/ 10.3133/ cir1480. ISSN 2330-5703 (online) iii Contents Migratory Bird Science at U.S. Geological Survey ..................................................................................1 List of Projects ................................................................................................................................................2 Project Narratives..........................................................................................................................................8 Migration and Nonbreeding Ecology ................................................................................................8 Breeding Ecology ��������������������������������������������������������������������������������������������������������������������������������24 Health, Disease, and Contaminants .................................................................................................36 Population Dynamics and Distributions ..........................................................................................50 Effects of Energy Development ........................................................................................................66 Support of Restoration and Species Recovery ..............................................................................76 Conservation Genetics .......................................................................................................................88 Response to Habitat Change and Management ............................................................................92 Monitoring and Population Estimation Techniques ....................................................................106 Acknowledgments .....................................................................................................................................118 References Cited........................................................................................................................................118 Appendix 1 List of Species ....................................................................................................................121 Appendix 2 Geographic Index ..............................................................................................................125 Appendix 3 Subject Index .....................................................................................................................128 iv Conversion Factors International System of Units to U.S. customary units Multiply By To obtain Length centimeter (cm) 0.3937 inch (in.) meter (m) 3.281 foot (ft) kilometer (km) 0.6214 mile (mi) kilometer (km) 0.5400 mile, nautical (nmi) meter (m) 1.094 yard (yd) Area hectare (ha) 2.471 acre square kilometer (km2) 247.1 acre hectare (ha) 0.003861 square mile (mi2) square kilometer (km2) 0.3861 square mile (mi2) Abbreviations BLM Bureau of Land Management BOEM Bureau of Ocean Energy Management DoD Department of Defense DOI Department of the Interior EPA U.S. Environmental Protection Agency GPS Global Positioning System GSM Global System for Mobile Communications NASA National Aeronautics and Space Administration NOAA National Oceanic and Atmospheric Administration NPS National Park Service NRCS National Resource Conservation Service NWR National Wildlife Refuge USACE U.S Army Corps of Engineers USDA U.S. Department of Agriculture USFS U.S. Forest Service USFWS U.S. Fish and Wildlife Service USGS U.S. Geological Survey Meadowlark at Reed Ranch, Douglas Wyoming. Photograph by Jennifer Strickland, U.S. Fish and Wildlife Service. A bald eagle at the National Elk Refuge. Photograph by Kari Cieszkiewicz, U.S. Fish and Wildlife Service. U.S. Geological Survey Migratory Bird Science, 2020–21 Edited by Aaron T. Pearse, Mark H. Sherfy, Mark Wimer, Mona Khalil, and Mark T. Wiltermuth American Breeding Bird Survey, which are in partnership Migratory Bird Science at with Canada and Mexico. USGS scientists lead research, U.S. Geological Survey research support, and monitoring from the continental scale to the local scale; organized in this report based on nine Bird conservation as an endeavor engages a broad research themes. The breadth of research activity includes range of partners and a coordinated effort across State and many new approaches for measuring the health of bird popu- Federal agencies, nongovernment organizations, universi- lations, for assessing threats to birds, and for addressing to ties and, at times, international partnerships. To understand those threats. information needs and respond to the many challenges in For each activity described, contact information is bird conservation, U.S. Geological Survey (USGS) scien- provided for project leads; therefore, please contact the cor- tists participate in Flyway committees, on Joint Venture responding project leader for more information. All activities boards and working groups, in professional organizations, represent collaborations, and partners also are listed. Finally, and in other conservation partnerships. These activities con- less visible in the activities are the students who are contrib- nect USGS scientists to conservation partners with whom uting to many of these studies, trained as part of a broader they work to address substantial challenges. More than one mission and an explicit mission for the Cooperative Fish hundred USGS scientists are dedicated to the scientific study and Wildlife Research Units, to become future scientists and of migratory birds. conservationists. This report presents the current (2021) representative USGS science is focused on a changing world. A 2019 breadth of activities of USGS scientists supporting the con- article published in Science, which included USGS data and servation and management of migratory birds. Ninety USGS analysis, pointed to an estimated loss of 3 billion birds in the scientists contributed to the project descriptions and other last 50 years (Rosenberg and others, 2019). Individuals and information detailing the work of the USGS. The science organizations across the bird conservation community are herein is organized and presented thematically by research forming larger partnerships to help understand the causes of strengths and by management topics. The report emphasizes these declines and how to prevent them. USGS scientists will the geographic framework of the North American Flyway continue to add to the understanding of changes in bird popu- councils through which USGS engages regularly with lations and, I invite you to work with the USGS in helping Federal and State government agencies and others who are meet existing and new challenges. responsible for managing migratory bird populations. USGS scientists lead activities that are central to bird conservation today—such as the activities spearheaded by the North American Bird Banding Laboratory and the North Mark Wimer, USGS–Wildlife Program Coordinator 2 U.S. Geological Survey Migratory Bird Science, 2020–21 List of Projects Migration and Nonbreeding Ecology A01. Migration and Wintering Ecology in the San Francisco Bay-Delta and Pacific Flyway A02. Spring and Fall Stopover Food Resources and Land-Use Patterns for Rocky Mountain Population Sandhill Cranes in the San Luis Valley, Colorado A03. Body Condition Index of Overwintering Mallards in Arkansas A04. Conserving the Flow of Ecosystem Services for Migratory Species A05. Linking Nonbreeding Areas and Reproductive Success of Golden Eagles in Denali National Park and Preserve, Alaska A06. Evaluating Dynamics of Habitat Resource Availability for Diving Ducks at Pools 13 and 19 of the Mississippi River A07. Avian Food Webs, Prey Resources, and Foraging Ecology A08. Spatial Ecology of Brown Pelicans in the South Atlantic