The mellow tortoise outlives the nervous rabbit by decades, even without help from predators. Opossums on Sapelo Island off Georgia have lived without much threat from predators for generations. They have become a laid-back lot, napping in the open in broad daylight, and can live a year longer than their more pressed mainland cousins. Studies with houseflies carry that idea further. With 100 flies in the same cage, they are less agitated by their cagemates, fly about less and live 20 days.
Temperature also can affect longevity.
Take that housefly and chill its vial down to 55 degrees Fahrenheit, and the fly will live more than six months. Cold bees also slow down, living months instead of weeks. Many aquatic creatures seem to live longer in cold water. Atlantic shad have spawning migrations like salmon, but the fish living south of Georgia spawn once and die while northern ones return again. In southern Canada, the shad may visit their chilly spawning streams seven times.