The big brown bat is a relatively large bat with a wingspan of 13 to 14 inches. Its dark color and slow flight help with identification. They are more likely to be active in cold weather than other bats and prefer human structures for roosting.

The big brown bat occurs throughout the state. In eastern Oregon it forages over the forest canopy, along roads through the trees, along the forest edge, over forest clearings, and along cliffs and canyon streams. In western Oregon, the species is usually associated with coniferous and deciduous forests.

Photo by ©Michael Durham