A bat with tall ears held by a gloved hand
Physical adaptations to their environments have given bats their looks. The large ears of this Townsend’s big-eared bat, held by a researcher, help it locate its prey.



Bats are the only mammals capable of sustained, flapping flight, which has given rise to a great diversity of species throughout the world. The bat species that have been documented in Yellowstone National Park are all insectivores (insect-eaters). To support the energy demands for flight, insectivorous bats must eat a large number of insects. Nursing females may consume their own body weight in food each night during the summer. In temperate environments, bats mate in late summer or autumn, just before entering into hibernation for the winter. During spring and summer, bats tend to be highly localized near sources of food, water, and roosting structures. They roost in natural habitats, including thermally heated caves, as well as in bridges, buildings, and other human structures, which can lead to conflicts with human use and historical preservation plans. Continue: Population, Habitat, and Physical Adaptations


Quick Facts

Species in Yellowstone


Where to See

Dawn and dusk in areas with insects.


  • Develop and reproduce slowly, which is unusual given their small body size.
  • Typically mate in the fall. In bats that hibernate, fertilization is delayed until the female emerges from hibernation. For most Greater Yellowstone bats, hibernation ends around mid-April and the females give birth in mid-June.
  • Most give birth to one pup a year, although four species in the greater Yellowstone area have two or more pups at a time. These species typically begin flying in 2–6 weeks, are weaned around 5–10 weeks, and become mature in 1–2 years.
  • Few predators specialize on bats. Predators are generally opportunistic and include owls, falcons, hawks, snakes, and raccoons.
  • Of bats that survive their first year, 40–80% survive 7–8 years; many bats live 10–30 years.

Contact the Park

Mailing Address:

P.O. Box 168
Yellowstone National Park, WY 82190-0168


(307) 344-7381

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