Modeling spatial variation in density of golden eagle nest sites in the western United States

PLoS One. 2019 Sep 30;14(9):e0223143. doi: 10.1371/journal.pone.0223143. eCollection 2019.

Abstract

In order to contribute to conservation planning efforts for golden eagles (Aquila chrysaetos) in the western U.S., we developed nest site models using >6,500 nest site locations throughout a >3,483,000 km2 area of the western U.S. We developed models for twelve discrete modeling regions, and estimated relative density of nest sites for each region. Cross-validation showed that, in general, models accurately estimated relative nest site densities within regions and sub-regions. Areas estimated to have the highest densities of breeding golden eagles had from 132-2,660 times greater densities compared to the lowest density areas. Observed nest site densities were very similar to those reported from published studies. Large extents of each modeling region consisted of low predicted nest site density, while a small percentage of each modeling region contained disproportionately high nest site density. For example, we estimated that areas with relative nest density values <0.3 represented from 62.8-97.8% ([Formula: see text] = 82.5%) of each modeling area, and those areas contained from 14.7-30.0% ([Formula: see text] = 22.1%) of the nest sites. In contrast, areas with relative nest density values >0.5 represented from 1.0-12.8% ([Formula: see text] = 6.3%) of modeling areas, and those areas contained from 47.7-66.9% ([Formula: see text] = 57.3%) of the nest sites. Our findings have direct application to: 1) large-scale conservation planning efforts, 2) risk analyses for land-use proposals such as recreational trails or wind power development, and 3) identifying mitigation areas to offset the impacts of human disturbance.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Conservation of Natural Resources / methods
  • Eagles / physiology*
  • Female
  • Humans
  • Male
  • Midwestern United States
  • Models, Statistical*
  • Nesting Behavior / physiology*
  • Northwestern United States
  • Population Dynamics / statistics & numerical data
  • Reproduction / physiology*
  • Southwestern United States

Grants and funding

This work was funded through U.S. Department of the Interior, Fish and Wildlife Service Agreements F14AC00691 and F17AC00995 to JRD, F14AC00569 to BRN and JDT, F14AP00144 and F17AC01011 to DL, and F14AC00264 and F17AC00824 to JLB.