Meeting Abstract
By migrating, birds may increase their reproductive success via exploitation of seasonally abundant food resources while increasing annual survival by avoiding resource-poor habitats during winter. Long-distance migration comes at an energetic cost, however, and may elevate oxidative stress. Telomeres, repetitive DNA regions that protect chromosomes from degradation, shorten during exposure to oxidative stress. We therefore hypothesized that a long-term cost of a migratory life history strategy may be greater telomere attrition. We predicted that within a population and among individuals of the same age, migrants would have shorter telomeres as compared to residents. We compared first-year individuals in an overwintering population of Dark-eyed Juncos (Junco hyemalis) that included both a migratory (J.h. hyemalis) and a resident (J.h. carolinensis) subspecies in western Virginia. As predicted, first-year migrants had shorter telomeres than first-year residents. These results suggest that accelerated telomere shortening may be one potential consequence of a migratory life history strategy.
