Telomere length and environmental conditions predict stress levels but not parental investment in a long-lived seabird

Telomeres are increasingly regarded as viable biomarkers of individual quality, and thus may be associated with other proximate markers of quality. We compared telomere length to such quality markers in a long-lived seabird, the thick-billed murre Uria lomvia, breeding under varying environmental conditions on 3 colonies in the Bering Sea. Individual quality was assessed using behaviors associated with parental investment (trip rate and nest attendance, determined by bird-borne data loggers), body condition, and physiological stress (baseline corticosterone). Telomere length was related to physiological stress and body condition, while parental investment in reproduction was not. This implies that maintenance of consistent levels of parental care was prioritized and that individual quality changes were expressed physiologically (changes in telomere length) rather than behaviorally. Under poor environmental conditions, short telomeres were associated with lower levels of physiological stress. However, under good environmental conditions, they were associated with higher levels of stress. These findings confirm that telomere length variation is related to patterns in stress hormones and support previous findings that environmental conditions are an important mediator of telomere dynamics.