Aging inevitably occurs both in humans and in other animals. However, life-span varies widely across species. Researchers have now found a possible general mechanism explaining differences in longevity. They investigated life history data of nearly 1400 bird species and found that avian life span varies considerably across the entire Earth, and that much of this variation can be explained by the species' body mass and clutch size and by the local diversity of predator species. The researchers were able to confirm a key prediction of the classical evolutionary theory of aging that had been proposed more than 50 years ago.

Source: Predators predict longevity of birds, study concludes