Birds as animal models for the comparative biology of aging: a prospectus.

Bird species are dramatically longer-lived than similar-sized mammals, in spite of two traits--high metabolic rate and elevated blood glucose--which some modern theories of aging suggest should be associated with accelerated senescence. As a consequence of their longevity, birds may possess specialized protective mechanisms against free radical and Maillard reaction damage, and may offer insight into medical interventions for retarding aging. In this review we have highlighted a number of bird species which are commercially available, easily maintained, and more thoroughly characterized with respect to basic physiology than many biogerontologists realize. There seem to us to be few intrinsic barriers to the development of several avian "mice"--extensively characterized species exhibiting exceptionally long life and retarded aging--and for these to become readily accessible as a laboratory resource for the gerontological research community.