A migratory lifestyle is associated with shorter telomeres in a songbird (Junco hyemalis)

Abstract

ABSTRACT For birds, a migratory lifestyle confers several benefits including avoidance of harsh winters and increased access to food resources during the breeding season. However, migration is energetically costly and elevates oxidative stress, which may contribute to increased mortality during migration. Oxidative stress is known to shorten telomeres, which are protective DNA regions on the ends of chromosomes. Thus, one consequence of migration may be accelerated telomere attrition. A migratory lifestyle may also increase telomere shortening via reduced investment into self-maintenance, as high mortality during migration may cause migrants to invest more in reproduction than residents. We therefore hypothesized that greater telomere attrition may reflect a long-term cost of a migratory life history strategy. We predicted that, 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 Slate-color...