Effects of nest exposure and spring temperatures on golden eagle brood survival: An opportunity for mitigation

Journal of Raptor Research
By: , and 

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Abstract

We examined Golden Eagle (Aquila chrysaetos) brood survival in relation to spring temperatures and exposure of nests to afternoon sun in southwestern Idaho from 1970 through 2012. Most (77%) nests classified as shaded in a subset of 96 nests had northwest to east aspects, and most (71%) nests classified as exposed had south to west aspects. We analyzed survival of 1154 Golden Eagle broods in 64 territories. Golden Eagle brood survival at shaded and exposed nests did not differ when the daily maximum temperature was <32.2°C. Survival in exposed nests declined as the number of days with maximum temperature ≥32.2°C increased, but survival in shaded nests did not change. All broods survived from hatching to fledging age in eight exposed nests with artificial shade structures installed over a 6-yr period. During the same period, 7 of 42 broods in nests without shade structures failed to reach fledging age, with two failures (29%) attributed to thermal stress. Use of artificial shade structures in exposed nests may reduce or prevent mortality caused by heat stress, and thus might be a potential tool for mitigation of “take” from anthropogenic structures and activities. Additional experimentation under an adaptive management framework could provide more information about the effectiveness of using shade structures to offset nestling mortality associated with increasing temperatures predicted by climate change models.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Effects of nest exposure and spring temperatures on golden eagle brood survival: An opportunity for mitigation
Series title Journal of Raptor Research
DOI 10.3356/JRR-17-100
Volume 53
Issue 1
Year Published 2019
Language English
Publisher The Raptor Research Foundation
Contributing office(s) Forest and Rangeland Ecosystem Science Center
Description 7 p.
First page 91
Last page 97
Country United States
State Idaho
Other Geospatial Morley Nelson Snake River Birds of Prey National Conservation Area