Birds and longevity: Does flight driven aerobicity provide an oxidative sink?

► Birds live remarkably long for the body size and have blood glucose levels on par with human diabetics. ► Mitochondrial free radical production is thought to impact lifespan, yet birds are athletic with mitochondrial rich tissues, which should shorten their lives. ► Reanalysis of the literature suggests that mitochondria are not sources, but most likely sinks for free radicals. ► Elevated blood glucose is explained by diminished insulin and elevated glucagon signaling, and this has been driven by the aerobic requirements of flight. ► Avian longevity has potentially piggybacked on aerobicity and an evolution of depressed insulin signaling pathways.