Effects of Drought on Golden Eagles: Spatial Patterns in Occupancy and Reproduction

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USGS scientists and collaborators investigated spatial patterns in occupancy and breeding success of golden eagles in the Altamont Pass Wind Resource Area, California and surrounding landscapes from 2014 – 2016, an exceptional drought period.

Site occupancy and reproduction by territorial pairs of eagles increased if a pair had successfully bred the prior year, but overall population productivity was relatively low and declined each year during the drought period. The greatest potential for site occupancy was characterized by rugged terrain with intermediate amounts of grassland containing oaks and conifers, and successful reproduction was most strongly influenced by the amount of precipitation received during the nesting period. This approach to mapping and quantifying site quality may offset the impacts of increasing human land-use and development by helping managers spatially prioritize compensation measures for golden eagles.

Wiens, J.D., Kolar, P.S., Hunt, G., Hunt, T., Fuller, M.R., Bell, D.A., 2018, Spatial patterns in occupancy and reproduction of Golden Eagles during drought: Prospects for conservation in changing environments: The Condor, v. 120, p. 106-124, https://doi.org/10.1650/CONDOR-17-96.1.