Common Name

Big Brown Bat

Scientific Name

Eptesicus fuscus

A common, widespread, medium-sized bat with long, chestnut brown fur and hairless black ears, face, wings, and tail. It forages at night over wooded areas, rivers, farmlands, and cities and rests during the day under loose tree bark, in tree hollows, rock crevices, buildings, or caves. The Big Brown Bat feeds on insects and will bite if handled.

  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Mammalia
  • Order: Chiroptera
  • Family: Vespertilionidae
  • Genus: Eptesicus
  • Species: Eptesicus fuscus
Habitat

Forest, Urban

Distribution

Distributed widely throughout North America, the Caribbean, and the northern portion of South America.

Seasonality

Spring, Summer, Fall

Abundance

Common

Activity Time

Nocturnal

Diet

Insects

Behavior

The big brown bat is nocturnal, roosting in sheltered places during the day. It will utilize a wide variety of structures for roosts, including mines, caves, tunnels, buildings, bat boxes, tree cavities, storm drains, wood piles, and rock crevices. They generally roost in cavities, though they can sometimes be found under exfoliating bark. Female big brown bats form maternity colonies to rear young. The size of these colonies can vary from 5 to 700 animals. Males of the species roost alone or in small groups during this time. Both sexes will roost together again in the late summer. Big brown bats enter into hibernation around November, often in a location less than 80 km (50 mi) away from their summer roosts.

Ecological Role

Conservation Status

Least Concern

Threats & Impacts

Notes