What is the lifespan of a bat?

The lifespan of a bat varies greatly depending on species, size, environment, and whether it lives in the wild or in captivity, but bats are surprisingly long-lived for small mammals, much longer than mice of similar size. In the wild, small insect-eating bats like little brown bats typically live 6 to 10 years on average, but many individuals live much longer, with banded little brown bats recorded living over 30 years in the wild. Big brown bats often live 10 to 20 years. Larger fruit bats like flying foxes can live 15 to 30 years in the wild. In captivity, where they are protected from predators, disease, harsh weather, and have regular food and veterinary care, bats live even longer, with some little brown bats living over 30 years and some flying foxes living over 30 to 40 years in zoos. Factors that influence lifespan include hibernation, bats that hibernate tend to live longer than non-hibernating bats because hibernation slows metabolism, body size, larger bats tend to live longer, and threats like white-nose syndrome, a fungal disease that has killed millions of bats in North America, which dramatically shortens lifespan. Compared to other small mammals like mice which live 1 to 3 years, bats are exceptionally long-lived, and their longevity is thought to be related to their ability to fly and their low reproductive rate of usually one pup per year.