Nyctinomops macrotis (2).jpeg

Photo Credit: Richard Hoyer

Big Free-tailed Bat

Nyctinomops macrotis

Order: Chiroptera

Suborder: Yangochiroptera

Family: Mollosidae

Call characteristics:

Low frequency caller (17-30 kHz range)


4 3/4 - 6 1/3 in

(12 – 16 cm)


  3/4 - 1 oz

(22 - 30 g)

The big free-tailed bat has brown to black fur, ears that meet in the middle of its forehead, and a long tail that extends beyond the tail membrane. Its habitat is in rocky canyons where this bat roosts in rock crevices and has been occasionally documented roosting in buildings and tree cavities. It is a strong flyer and migrates between winter and summer homes. Breeding colonies of the big free-tailed bat have been found as far north as Colorado. This species mostly feeds on moths but will sometimes eat other insects including grasshoppers, ants, and beetles. Mothers give birth to one pup a year.

Conservation Status

Canada Species at Risk
Nyctinomops macrotis (1).jpeg

Photo Credit: Richard Hoyer




NABat utilizes monitoring data provided by a broad network of partners to support regional and range-wide inferences about changes in the distributions and abundances of bat populations facing current and emerging threats.

Information used to populate this page was obtained from the following sources:


NatureServe Explorer

United States Fish and Wildlife Service Environmental Conservation Online System 

Bat Conservation International Bat Profiles

National Atlas of the United States. (2011). North American Bat Ranges, 1830-2008. National Atlas of the United States. Available at:

Taylor, M. 2019. Bats: an illustrated guide to all species. Washington, DC: Smithsonian Books.