Predicting the spatial distribution of wintering golden eagles to inform full annual cycle conservation in western North America.
Zachary P Wallace, Bryan E Bedrosian, Jeffrey R Dunk, David W LaPlante, Brian Woodbridge, Brian W Smith, Jessi L Brown, Todd M Lickfett, Katherine Gura, Dave Bittner, Ross H Crandall, Rob Domenech, Todd E Katzner, Kevin J Kritz, Stephen B Lewis, Michael J Lockhart, Tricia A Miller, Katie Quint, Adam Shreading, Steve J Slater, Dale W Stahlecker
Author Information
Zachary P Wallace: Wyoming Natural Diversity Database, University of Wyoming, Laramie, Wyoming, United States of America. ORCID
Bryan E Bedrosian: Teton Raptor Center, Wilson, Wyoming, United States of America.
Jeffrey R Dunk: Department of Environmental Science and Management, California State Polytechnic University, Humboldt, Arcata, California, United States of America.
David W LaPlante: Natural Resource Geospatial, Yreka, California, United States of America.
Brian Woodbridge: California State Polytechnic University, Humboldt, Arcata, California, United States of America.
Brian W Smith: U.S. Fish and Wildlife Service, Denver, Colorado, United States of America.
Jessi L Brown: Sparrowhawk Data Science, Reno, Nevada, United States of America.
Todd M Lickfett: U.S. Fish and Wildlife Service, Denver, Colorado, United States of America.
Katherine Gura: Teton Raptor Center, Wilson, Wyoming, United States of America.
Dave Bittner: Wildlife Research Institute, Inc., Julian, California, United States of America.
Ross H Crandall: Wyoming Game and Fish Department, Habitat Protection Program, Pinedale, Wyoming, United States of America.
Rob Domenech: Raptor View Research Institute, Missoula, Montana, United States of America.
Todd E Katzner: U.S. Geological Survey, Boise, Idaho, United States of America.
Kevin J Kritz: U.S. Fish and Wildlife Service, Denver, Colorado, United States of America.
Stephen B Lewis: U.S. Fish and Wildlife Service, Juneau, Alaska, United States of America.
Michael J Lockhart: Wildlands Bio-Consulting, Laramie, Wyoming, United States of America.
Tricia A Miller: Conservation Science Global, Cape May, New Jersey, United States of America.
Katie Quint: Wildlife Research Institute, Inc., Julian, California, United States of America.
Adam Shreading: Raptor View Research Institute, Missoula, Montana, United States of America.
Steve J Slater: HawkWatch, International, Salt Lake City, Utah, United States of America.
Dale W Stahlecker: Eagle Environmental, Inc., Santa Fe, New Mexico, United States of America.
Wildlife conservation strategies focused on one season or population segment may fail to adequately protect populations, especially when a species' habitat preferences vary among seasons, age-classes, geographic regions, or other factors. Conservation of golden eagles (Aquila chrysaetos) is an example of such a complex scenario, in which the distribution, habitat use, and migratory strategies of this species of conservation concern vary by age-class, reproductive status, region, and season. Nonetheless, research aimed at mapping priority use areas to inform management of golden eagles in western North America has typically focused on territory-holding adults during the breeding period, largely to the exclusion of other seasons and life-history groups. To support population-wide conservation planning across the full annual cycle for golden eagles, we developed a distribution model for individuals in a season not typically evaluated-winter-and in an area of the interior western U.S. that is a high priority for conservation of the species. We used a large GPS-telemetry dataset and library of environmental variables to develop a machine-learning model to predict spatial variation in the relative intensity of use by golden eagles during winter in Wyoming, USA, and surrounding ecoregions. Based on a rigorous series of evaluations including cross-validation, withheld and independent data, our winter-season model accurately predicted spatial variation in intensity of use by multiple age- and life-history groups of eagles not associated with nesting territories (i.e., all age classes of long-distance migrants, and resident non-adults and adult "floaters", and movements of adult territory holders and their offspring outside their breeding territories). Important predictors in the model were wind and uplift (40.2% contribution), vegetation and landcover (27.9%), topography (14%), climate and weather (9.4%), and ecoregion (8.7%). Predicted areas of high-use winter habitat had relatively low spatial overlap with nesting habitat, suggesting a conservation strategy targeting high-use areas for one season would capture as much as half and as little as one quarter of high-use areas for the other season. The majority of predicted high-use habitat (top 10% quantile) occurred on private lands (55%); lands managed by states and the Bureau of Land Management (BLM) had a lower amount (33%), but higher concentration of high-use habitat than expected for their area (1.5-1.6x). These results will enable those involved in conservation and management of golden eagles in our study region to incorporate spatial prioritization of wintering habitat into their existing regulatory processes, land-use planning tasks, and conservation actions.
References
PLoS One. 2018 Nov 21;13(11):e0205204
[PMID: 30462652]
PLoS One. 2019 Jan 14;14(1):e0210643
[PMID: 30640947]
