Golden eagle population surveys in the vicinity of the Altamont Pass Wind Resource Area, California, 2014–21

Abstract

..........................................................................................................................................................1 Background and Research Objectives ......................................................................................................1 Methods...........................................................................................................................................................2 Study Area..............................................................................................................................................2 Golden Eagle Monitoring Design and Survey Protocol ..................................................................2 Results .............................................................................................................................................................3 Site Occupancy and Reproduction ....................................................................................................3 Northern Diablo Range and Altamont Wind Resource Area ................................................3 Altamont Pass Wind Resource Area ........................................................................................4 Observations of Territorial and Non-territorial Subadults .............................................................5 Communal Roosting Behavior ............................................................................................................8 Summary..........................................................................................................................................................8 Megafire—An Emergent Threat to Golden Eagles? .......................................................................9 Acknowledgments .......................................................................................................................................10 References Cited..........................................................................................................................................11 Appendix 1. Map of Survey Sites and Activity Centers Used by Territorial Pairs of Golden Eagles in the Altamont Pass Wind Resource Area, 2019–21 ....................................13 Appendix 2. Territory-Specific Observations of Territorial Pairs of Golden Eagles Located near the Altamont Pass Wind Resource Area, 2019–21 ...........................................14