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Species Description

Little Brown Myotis

Myotis lucifugus


Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Chiroptera
Family: Vespertilionidae


Dark yellowish or grayish brown to gray, depending on species. These small to medium-sized bats ranges from 8 - 9.5 cm (3.1 - 3.7 in) in total length. The tragus, a projection which extends from the base of the inside of the external ear, is long and pointed rather than blunt and rounded. All of the Mouse-eared Bats have simple unmodified snouts, and a tail that reaches the end of the membrane from the hind legs. This membrane is never thickly furred. Many of the Mouse-eared Bat species are difficult to tell apart from one another, even in a museum.

Life Cycle

Breeding generally takes place in late autumn, and 1 - 2 young (depending on the species) are born in May or June of the following spring. In some species, females gather together to form a "maternity colony" of up to several hundred individuals, and remain together until August or September when the young are able to fend for themselves. The young are able to fly within 3 - 5 weeks after birth. Sexual maturity is reached in 1 - 2 years, depending on species.

Natural History

The Mouse-eared Bats use many different sites for summer roosts, including caves, old mine shafts, buildings, hollow trees, the area beneath sheets of loose tree bark, rock crevices, and cliff faces. Some species are very particular about their roosting site and use only one or two kinds of summer roosts. To hibernate they may travel as far as 482.8 km (300 mi) to their winter roost, which is usually a cave or abandoned mine shaft. In the southern portions of its range, a Mouse-eared Bat may remain active all year, depending on species. Members of the genus usually feed over water or forests adjacent to water. Some species may travel as far as 24.1 km (15 mi) on foraging flights. Their diet is composed mostly of mayflies, midges, flies, moths, beetles, and mosquitos. The Little Brown Myotis can live for 30 years. This is the longest life span known for a bat. As in all bats, members of this genus use echolocation to find food and to avoid collisions with obstacles.


The Myotis bats are the commonest and most widespread of all the groups of bats in North America. The Little Brown Myotis ranges across the entire state of Georgia; it is widespread across the United States and Canada.

Conservation Status

This species is not considered to be threatened at this time.

Similar Species

The Big Brown Bat is noticably larger and the Evening Bat has a blunt, forward-curved tragus.