Habitat selection and site fidelity on winter home ranges of Eastern Whip-poor-wills (Antrostomus vociferus)

Abstract

The Eastern Whip-poor-will (<em>Antrostomus vociferus</em>), an aerial insectivore experiencing population declines, was recently upgraded from Least Concern to Near Threatened status by the International Union for Conservation of Nature (IUCN), highlighting research needs to better understand threats to the species. Because little information is known concerning wintering ground ecology for the species, we used archival global positioning system (GPS) tags to examine wintering ground movement patterns and habitat selection for birds that breed throughout Massachusetts. Key findings document highly variable locations of overwintering home ranges (where birds overwinter from coastal South Carolina to mountains of El Salvador), 100% site fidelity to wintering grounds between years, and 20% of males occupying two home ranges in a season. Furthermore, birds avoided crop cover at the 5-km scale and preferred open and closed forest covers at the home range scale. Although some landscapes used by Whip-poor-wills had high crop cover, crop cover averaged 3.7 times greater in available plots than used plots at the 5-km spatial scale. Additionally, mean closed forest cover was 1.8x greater in the second home range for mobile birds than their first home range. The information gained from this study provides an improved understanding of the ecological needs for the Eastern Whip-poor-will on the wintering grounds and is critical for applying full life-cycle conservation strategies.