Ecosystem processes, land cover, climate, and human settlement shape dynamic distributions for golden eagle across the western US

Authors

J.D. Tack, Colorado State University, Fort Collins & US Geological Survey, Fort Collins Science CenterFollow
Barry R. Noon, Colorado State University, Fort CollinsFollow
Zachary Bowen, US Geological Survey, Fort Collins Science CenterFollow
Brad C. Fedy, University of Waterloo, WaterlooFollow

Document Type

Article

Date of this Version

2020

Citation

Animal Conservation 23 (2020) 72–82

doi:10.1111/acv.12511

Comments

U.S. government works are not subject to copyright.

Abstract

Species–environment relationships for highly mobile species outside of the breeding season are often highly dynamic in response to the collective effects of everchanging climatic conditions, food resources, and anthropogenic disturbance. Capturing dynamic space-use patterns in a model-based framework is critical as model inference often drives place-based conservation planning. We applied dynamic occupancy models to broad-scale golden eagle Aquila chrysaetos survey data collected annually from 2006 to 2012 during the late summer post-fledging period in the western US. We defined survey sites as 10 km transect segments with a 1 km buffer on either transect side (n = 3540). Derived estimates of occupancy were low (4.4–7.9%) and turnover rates – the probability that occupied sites were newly occupied – were high (88–94%), demonstrating that annual transiency in occupancy dominates late summer behavior for golden eagles. Despite low philopatry during late summer, variation in golden eagle occupancy could be explained by a suite of land cover and annual-varying covariates including gross primary productivity, drought severity, and human disturbance. Our summary of 13 years of predicted occupancy by golden eagles across the western United States identified areas that are consistently used and that may contribute significantly to golden eagle conservation. Restricting development and targeting mitigation efforts in these areas offers practitioners a framework for conservation prioritization.