Hillar Klandorf Avian longevity is a mystery that has intrigued the scientific community for as long as it has been aware of the paradox.
Birds live considerably longer than mammals of comparable body size.
Given certain inherently avian characteristics, prevailing theories suggest that birds should be more susceptible than mammals to the degenerative process of aging. The higher metabolic rates, coupled with the relatively extreme longevity of many avian species, result in a much greater lifetime energy expenditure per unit mass by birds than mammals. It is assumed that lifetime energy expenditure correlates with an organism's cumulative exposure to potentially damaging free radicals. Free radicals are oxygen-derived molecules that contain one or more unpaired electrons and that react with other molecules, acquiring or giving up an electron to achieve stability. An animal's body produces these destructive molecules as normal byproducts of metabolism.