Avian migration is an energy-intensive behavior undertaken in both spring and fall by millions of songbirds in order to reach distant breeding and wintering grounds. When faced with ecological barriers (e.g., bodies of water), migrants in poor energetic condition alter their migratory trajectory in order to replenish energy reserves in suitable stopover habitats prior to crossing the barrier. This study is a longitudinal (i.e., repeated measures) experiment to determine if changes in energetic condition directly affect the orientation of individual Zonotrichia albicollis arriving on the south shore of Lake Ontario. Surprisingly, the birds in this study show a similar (bimodal) orientation regardless of season or energetic condition. Although these results are inconclusive, the bimodal distribution of these sparrows makes reverse orientation undetectable. Therefore, this species is a poor model for testing the hypothesis of this study, and other species with unimodal orientation preferences should be tested using similar research methods.
|Presenter:||Jennalee Holzschuh (Graduate Student)|
|Time:||9:15 am Session I|