In migratory birds, among- and within-species heterogeneity in response to climate change may be attributed to differences in migration distance and environmental cues that affect timing of arrival at breeding grounds. We used eBird observations and a within-species comparative approach to examine whether migration distance (with latitude as a proxy) and weather predictors can explain spring arrival dates at the breeding site in a raptor species with a widespread distribution and diverse migration strategies, the American Kestrel Falco sparverius. We found an interactive effect between latitude and spring minimum temperatures on arrival dates, whereby at lower latitudes (short-distance migrants) American Kestrels arrived earlier in warmer springs and later in colder springs, but American Kestrels at higher latitudes (long-distance migrants) showed no association between arrival time and spring temperatures. Increased snow cover delayed arrival at all latitudes. Our results support the hypothesis that short-distance migrants are better able to respond to conditions on the breeding ground than are long-distance migrants, suggesting that long-distance migrants may be more vulnerable to shifts in spring conditions that could lead to phenological mismatch between peak resources and nesting.
This is the peer reviewed version of the following article, published by Wiley on behalf of the British Ornithologists' Union:
Powers, Breanna F.; Winiarski, Jason M.; Requena-Mullor, Juan M.; & Heath, Julie A. (2021). Intra-Specific Variation in Migration Phenology of American Kestrels (Falco sparverius) in Response to Spring Temperatures. IBIS, 163(4), 1448-1456.,
which has been published in final form at https://doi.org/10.1111/ibi.12953. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. This article may not be enhanced, enriched or otherwise transformed into a derivative work, without express permission from Wiley or by statutory rights under applicable legislation. Copyright notices must not be removed, obscured or modified. The article must be linked to Wiley’s version of record on Wiley Online Library and any embedding, framing or otherwise making available the article or pages thereof by third parties from platforms, services and websites other than Wiley Online Library must be prohibited.
Powers, Breanna F.; Winiarski, Jason M.; Requena-Mullor, Juan M.; and Heath, Julie A.. (2021). "Intra-Specific Variation in Migration Phenology of American Kestrels (Falco sparverius) in Response to Spring Temperatures". IBIS, 163(4), 1448-1456. https://doi.org/10.1111/ibi.12953
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