Scientific Name
Eptesicus fuscus
Global Conservation Status (IUCN)
Least Concern

Data Sheet

The big brown bat is found in virtually every American habitat ranging from timberline meadows to lowland deserts, though this species is most abundant in deciduous forest areas. It also is often abundant in suburban areas of mixed agricultural use. This species ranges from extreme northern Canada, throughout the United States and south to the extreme southern tip of Mexico. Traditionally, these bats form maternity colonies beneath loose bark and in small cavities of pine, oak, beech, bald cypress, and other trees. Common maternity roosts can also be found in buildings, barns, bridges, and bat houses.

Big brown bats are generalists in their foraging behavior and habitat selections, seemingly showing little preference for feeding over water vs. land, or in forests vs. clearings.Small beetles are their most frequent prey, yet big brown bats will consume prodigious quantities of a wide variety of night-flying insects.

Like all insect-eating bats, big brown bats contribute mightily to a healthy environment and are vital players in pest control. Numerous feeding studies of big brown bats substantiate that they consume significant crop and forest pests including cucumber beetles, ground beetles, scarab beetles, snout beetles and stink bugs, in addition to numerous species of leafhoppers and moths. Like many bat species, reproductive females often can consume their body weight in insects each night. In fact, a colony of 150 big brown bats can consume enough adult cucumber beetles in one summer to prevent egg-laying that could produce 33 million of their root-worm larvae, a major pest of corn crops.

Big brown bats rank among America’s most beneficial animals. As they are forced out of traditional forest habitats due to encroaching human populations, logging, and habitat modification, the bats increasingly move into close human contact and take up residence in buildings and other man-made structures. Bats and humans can coexist peacefully. Sometimes, designing and installing bat-specific artificial roosts is the best option to keep bats out of our homes, yet near enough so that we can continue to benefit from their insect-eating capabilities. Though many species like the big brown bat rank among our most abundant and widespread bats, they nevertheless deserve attention from conservation and education initiatives to assure healthy environments.