Finding dark routes A migrating nocturnal bird avoids artificial light during both travel and stopovers


SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 – Febuary 28, 2021

Meeting Abstract


1-9  Sat Jan 2  Finding dark routes: A migrating nocturnal bird avoids artificial light during both travel and stopovers Korpach, AM*; Garroway, CJ; Mills, AM; von Zuben, V; Davy, CM; Fraser, KC; University of Manitoba, Winnipeg, MB; University of Manitoba, Winnipeg, MB; York University, Toronto, ON; Ontario Ministry of Natural Resources and Forestry, Peterborough, ON; Ontario Ministry of Natural Resources and Forestry, Peterborough, ON; University of Manitoba, Winnipeg, MB alicia_korpach@hotmail.com

Flying animals use aerial habitats to forage, communicate, and travel, and anything that fragments that habitat may limit their ability to use airspace efficiently. As artificial light at night continues to grow, nocturnally migrating birds increasingly encounter airscapes fragmented by light. Attraction to bright lights by groups of nocturnal migrants is well documented, but there is also evidence of light avoidance, particularly during stopovers. We do not have a clear understanding of how birds that do not travel in groups, and nocturnal species specifically, perceive and navigate artificial light along their full migratory paths. We investigated potential selection or avoidance of artificial light during migration in a highly nocturnal species, the Eastern Whip-poor-will (Antrostomus vociferous). We GPS-tracked birds on their southbound migrations through eastern North America, and compared their routes with artificial light, dark-sky connectivity, and terrestrial connectivity surfaces in a resource selection framework. The degree of connectivity of dark skies was the best predictor of Whip-poor-will routes, and stopovers occurred almost exclusively in dark, rural areas. These dark-sky preferences were detected in analyses at various spatial scales, providing evidence for avoidance of, rather than attraction to, artificial light. The presence and connectivity of an aerial resource, dark skies, influenced movements of this nocturnal species, and our findings may apply to other aerial migrants that use dark skies.

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