Telomere length is a strong predictor of foraging behavior in a long-lived seabird

Telomeres are an increasingly studied component of physiological ecology. However, in long-lived birds a large telomere loss with chronological age is not the norm. Telomeres are now regarded less as a chronological aging tool and more as an indicator of individual quality, residual lifespan, or biological age. If telomeres indicate biological aging processes, then they should also be associated with other variables that change with age, especially foraging and reproductive behaviors. This study compared telomere length to a suite of foraging parameters in Thick-billed Murres breeding on three colonies in the Bering Sea. Telomere length, environmental conditions at colonies, and sex played pivotal roles in determining foraging habitat selection. Spatial habitat use, foraging efficiency, and prey selection variables all changed with telomere length. The behavioral evidence indicates that despite losing telomeres, birds with short telomere length retain their ability to use the environment efficiently. This indicates that aging birds remain behaviorally flexible, despite paying physiological costs. Changes in spatial use were largely sex-dependent: females and males differed in their use of the environment as telomere lengths declined. Prey selection was related to telomere length and colony; changes in murre trophic level depended on telomere length, but their direction also depended on habitat quality. We found much support for the continued able functioning of birds with shorter telomeres, indicating that physiological aging does not carry only costs. Murres appear to modify their behavior depending on environmental conditions as their physiological reserves decline