Embryonic growth rate affects telomere attrition: an experiment in a wild bird

High growth rate is associated with a short lifespan, but the physiological basis for this trade-off is not well known. Telomere(definition) length predicts individual lifespan and in this study we investigated whether embryonic growth rate, manipulated using incubation temperature, affects erythrocyte telomere length in a wild bird species, the common tern (Sterna hirundo). A 1oC lower incubation temperature decreased growth rate by 5%, without affecting size at hatching. The slower growth was associated with 147 base pairs longer telomere length at hatching. If carried through to adulthood, this effect would correspond with an approximately 3 year longer lifespan. Our results thus suggest that an effect of growth rate on lifespan may be mediated by telomere dynamics, or a physiological process reflected by telomere length.