Meeting Abstract
Across the year, energetic demands fluctuate as birds reproduce, molt, and migrate. A growing body of evidence suggests that challenges experienced within any of these behavioral stages affect the energetics and/ or phenology of subsequent stages. Such consequences or “carry-over effects” may affect the timing and success of future life within or across years. While there is growing evidence for carry-over effects of spring migration on reproduction, few studies have examined the influence of breeding time on autumnal migratory departure. Due to the harsh weather conditions of spring and fall, arctic-breeding songbirds experience a narrow window of time in which to breed, molt, and depart for migration. We used arctic breeding Gambel’s white-crowned sparrow (Zonotrichia leucophrys gambelii) as a study system in which to investigate carry-over effects of breeding on the post-reproductive period. Data were collected during 2014 and 2015 at Toolik Field Station on the North Slope of Alaska. Birds were monitored using hand-held and automated radio-telemetry through the post-fledging period. Meteorological data were also collected to test for a relationship between weather and migratory departure. We use these data to evaluate whether longer term carry-over effects from breeding or short term fluctuations in weather conditions are more important in determining timing of fall migration. Results suggest that there is tremendous variation in migratory departure timing across individuals and that renesting pairs could delay migration. Additionally, local weather conditions like early snowfall may affect migratory departure. We evaluate these findings in light of current and projected climate change in the Arctic.
