Wyoming and Uinta Basins Golden Eagle Conservation Strategy Prepared for U.S. Fish and Wildlife Service Western Golden Eagle Team by the Wyoming Natural Diversity Database and Eagle Environmental, Inc. Wyoming and Uinta Basins Golden Eagle Conservation Strategy Version September 20, 2019 Disclaimer The findings and conclusions in this article are those of the authors and do not necessarily represent the views of the U.S. Fish and Wildlife Service. Suggested Citation Wallace, Z., G. Bedrosian, B. Woodbridge, G. Williams, B.E. Bedrosian, and J. Dunk. 2019. Wyoming and Uinta Basins Golden Eagle Conservation Strategy. Unpublished report prepared for the U.S. Fish and Wildlife Service Western Golden Eagle Team by the Wyoming Natural Diversity Database and Eagle Environmental, Inc. i Acknowledgments This synthesis was authored by Zach Wallace with contributions from Geoffrey Bedrosian, Brian Woodbridge, Gary Williams, Bryan Bedrosian, and Jeffery Dunk. Reviews were provided by Michael Collopy, Pat Deibert, Destin Harrell, Bob Oakleaf, Andrea Orabona, Katie Powell, Charles Preston, and Patricia Sweanor. Guidance was provided by the Western Golden Eagle Team (WGET): Brian Woodbridge, Todd Lickfett, Gary Williams, Geoffrey Bedrosian, David Leal, Katie Powell, Hillary White. Data products and expertise were provided by the WGET Modeling Team: Jeffery Dunk, David LaPlante, Brian Woodbridge, Todd Lickfett, Geoffrey Bedrosian, Jessi Brown, Barry Noon, and Jason Tack. Special thanks to the numerous researchers and agency personnel who took time to share expertise and data from the region: Becky Abel (Idaho Fish and Game), Bryan Bedrosian (Teton Raptor Center), Allison Begley (Montana Fish, Wildlife & Parks), Frank Blomquist (Wyoming BLM), Ross Crandall (Craighead Beringia South), Terry Creekmore (Wyoming Game and Fish), Natasha Hadden (Utah BLM), Pat Hnilicka (USFWS), Dylan Hopkins (Utah State), Brad Jost (Wyoming BLM), Lorraine Keith (Wyoming BLM), Heath Cline (Wyoming BLM), Mike Kochert (USGS), Art Lawson (Eastern Shoshone and Northern Arapaho Tribal Fish and Game Department), Brian Maxfield (Utah Division of Wildlife Resources), Gwyn McKee (Great Plains Wildlife Consulting, Inc.), Bob Oakleaf (Wyoming Game and Fish), Charles Preston (Draper Natural History Museum), Liza Rossi (Colorado Parks and Wildlife), Shawn Stewart (Montana Fish, Wildlife & Parks), Patricia Sweanor (USFWS), Zack Walker (Wyoming Game and Fish), and Leah Yandow (Wyoming BLM). ii Contents Ecoregional Conservation Strategies for Golden Eagles .......................................... 1 I. Conservation Assessment ........................................................................................ 3 1. Introduction to Conservation Strategy Area .................................................................. 3 1.1. Geographic boundaries .............................................................................................. 4 1.2. Dominant geographic features ................................................................................... 5 1.2.1. Topography .......................................................................................................... 5 1.2.2. Climate ................................................................................................................ 5 1.2.3. Vegetation ........................................................................................................... 6 1.2.4. Level-IV ecoregions ............................................................................................. 9 1.3. Surface management and development ...................................................................11 1.3.1. Surface management .........................................................................................11 1.3.2. Human development ..........................................................................................13 2. Golden Eagle Populations ..............................................................................................15 2.1. Breeding populations ................................................................................................15 2.1.1. Abundance and density ......................................................................................16 2.1.2. Spacing, home range, and core areas ................................................................19 2.1.3. Breeding habitat ................................................................................................19 2.1.4. Relative nesting territory density model ...........................................................26 2.1.5. Fecundity ............................................................................................................32 2.1.6. Breeding season diet ..........................................................................................36 2.1.7. Prey community .................................................................................................39 2.2. Movements and migration ........................................................................................40 2.2.1. Movements of locally produced young ...............................................................41 2.2.2. Movements of territorial adults .........................................................................41 2.2.3. Movement into the region from elsewhere ........................................................42 2.2.4. Migration models ...............................................................................................42 2.3. Winter ecology and distribution ...............................................................................46 2.3.1. Abundance and density ......................................................................................46 2.3.2. Habitat use .........................................................................................................48 2.3.3. Winter-season habitat use model ......................................................................48 2.3.4. Winter diet and prey communities ....................................................................52 3. Population Ecology .........................................................................................................53 3.1. Status and trend .......................................................................................................53 3.2. Population limiting factors – Direct effects on survival...........................................54 3.2.1. Energy Infrastructure ........................................................................................56 3.2.2. Collisions with vehicles ......................................................................................61 3.2.3. Contaminants .....................................................................................................64 3.2.4. Disease and parasites ........................................................................................67 3.2.5. Persecution and poaching ..................................................................................70 3.2.6. Drowning ............................................................................................................70 3.3. Population limiting factors – Fecundity ...................................................................71 3.3.1. Prey resource limitation .....................................................................................71 3.3.2. Disturbance ........................................................................................................72 iii 4. Conservation and Risk Assessments ............................................................................76 4.1. Conservation status ..................................................................................................76 4.2. Conservation prioritization .......................................................................................76 4.2.1. Breeding priority areas ......................................................................................77 4.2.2. Winter priority areas .........................................................................................82 4.2.3. Migration priority areas .....................................................................................83 4.3. Spatial risk assessments ...........................................................................................83 4.3.1. Electrocution ......................................................................................................85 4.3.2. Wind resource development ...............................................................................91 4.3.3. Oil and gas development ....................................................................................97 4.3.4. Lead exposure ..................................................................................................102 II. Conservation Strategy .......................................................................................... 107 1. Electrocution prevention ..............................................................................................108 2. Wind resource development ........................................................................................111 3. Oil and gas development, mining, and power generation ..........................................114 4. Collisions with vehicles ................................................................................................117 5. Collisions with transmission structures ......................................................................118