MAMMALS: BATS

Big Brown Bat, Eptesicus fuscus

Family Vespertilionidae (Vespertilionid Bats)

Size: 5" with tail

Range: Throughout Colorado

Habitat: A wide variety, including woodlands, buildings, and caves

As a group, bats are the only mammals that truly fly, using wings made of a thin membrane stretched across elongated forearms and fingers. The big brown bat is widely distributed. It is fairly large, with fur that is brown above and lighter below, with blackish wing membranes. There is a fleshy projection at the base of the ear (the tragus), which is short and rounded. Big brown bats are nocturnal, roosting by day in dark, secluded areas such as caves or old buildings. They emerge at night to forage for beetles and other insects, locating them primarily by echolocation, emitting high-pitched chirps and receiving reflected sound with their complex, large ears.