Bats in New Mexico

Allen's Big-eared Bat

ALLEN's BIG-EARED BAT - Idionycteris phyllotis

Weight: 8-16 grams

Wingspan: 31-35 centimeters

Distribution: Southwestern United States to central Mexico.

Ecology and Behavior: A rather large bat with enormous ears. When at rest, the huge ears lie along the back, often curled into the shape of a ram's horn. Allen's big-eared bat usually inhabits forested areas of the mountainous Southwest, and is relatively common in pine-oak forested canyons and coniferous forests, but it also may occur in non-forested, arid habitats. At most sites where this species occurs, cliffs, outcroppings, boulder piles, or lava flows are nearby. Day roosts may include rock shelters, caves, and mines. It leaves the roost only after complete darkness, and usually flies about 10 meters (33 feet) above ground. It emits loud calls at about 1-second intervals. Flight is slower than the free-tailed bats, but swifter than most other bats. In close quarters, this species flies slowly, is highly maneuverable, able to hover, and can fly vertically. In more open situations, it uses fast, direct flight. The sexes segregate geographically during summer months, with females gathering into maternity colonies and males possibly remaining solitary, roosting elsewhere. Seasonal movements and winter whereabouts and activities are unknown.

Food Habits: Primarily small moths, but soldier beetles, dung beetles, leaf beetles, roaches, and flying ants are also eaten.

Reproduction: One baby is born in June or July.

Status of Populations: Locally common, but rare over most of range.

Thanks to T. L. Best, J. S. Altenbach, and M. J. Harvey for permission to reprint portions of Bats of the Western United States, 1998.

New Mexico Energy, Minerals and Natural Resources Department | Copyright
1220 South St. Francis Drive | Santa Fe, NM 87505
Webmaster   |   EMNRD Legal Disclaimer