Myotis evotis
(Long-eared Myotis)

Order: Chiroptera
Order Description: Bats
Family Description:

The upper fur is brownish at the tips and dark at the base. The dark to blackish glossy rounded ears extend past the nostrils and can exceed three-quarters of an inch (=20mm). The tragus Click word for definitionis extends over one-half of the length of the ear.

A western distribution including British Columbia east across southern Canada to Saskatchewan, south along the western edge of the Dakotas Nebraska, much of Colorado and New Mexico, west across northern Arizona, Nevada, to the Pacific Coast from Baja California, through California, Oregon and Washington. It has been collected in fifteen Idaho counties but likely occurs in most of the Gem State.

This bat is found in a wide range of habitats often associated with forests. It is found under exfoliating bark, in cavities in trees, and in stumps resulting from logging. In shrub communities, is may be found in crevices in cliffs and rocks on the ground, in lava-tube caves, and abandoned mines. It has also been found occasionally in buildings and under bridges.

Found (from near sea level along Pacific Coast, to about 2830 m in Wyoming), mostly in forested areas, especially those with broken rock outcrops; also found in shrublands, over meadows near tall timber, along wooded streams, and over reservoirs. Idaho study found roosts were always located near water. Species is common in lodgepole pine forests.

Primarily moths and beetles but other insects including lacewings, true bugs, wasps and bees are eaten. This species may glean insects from the surface of a variety of desert shrubs but it also occurs and feeds in coniferous Click word for definitionforests.

In northern Idaho, long-eared myotis appear to feed near the back of mines, especially at the portal. They do not seem to use these mines for night roosting or winter hibernation. A few to a moderate number of individuals are often associated with areas adjacent to reservoirs or streams containing areas of slow-moving water. Small nursery colonies containing females and young form. Nonbreeding small mixed sex colonies are also known to occur during summer. More information on winter roosting ecology is needed for this species.

Widespread and not uncommon species, but little is known about its habits. Reportedly emerges late in evening to feed, though some studies report earlier emergence. Forages over water or among trees. Usually feeds by picking prey from surface of foliage, tree trunks, rocks, or ground; may fly slowly around shrub searching for emerging moths, or perhaps nonflying prey. Known to forage with long-legged myotis, big brown bat, silver-haired bat, and hoary bat, but Idaho study found species foraged earlier in evening than several other bat species. Often roosts in buildings; may also roost Click word for definitionin hollow trees, mines, caves, and fissures.

Swarming and mating take place prior to hibernation Click word for definitionand sperm is stored over winter. Fertilization ensues when ovulation occurs in the spring. A single pup is born, as late as mid July in northern Idaho. Each pup weights about 20 percent of the body mass of the female.

Mating occurs in fall; ovulation Click word for definitionand fertilization Click word for definitionare delayed until spring. Births have been recorded in mid-July in western Washington. Young and lactating Click word for definitionfemales have been recorded in late July in New Mexico. Female and newborn young have been recorded in late June in California. Female produces 1 young. South Dakota study found that male young-of-year reached approximate adult size in early August.

Status: Unprotected nongame species
Global Rank: G5
State Rank: S3

Important State References:
Bonnell, M.L. 1967. Emergence and foraging behavior in small populations of Idaho bats. M.S. Thesis, Univ. Idaho, Moscow. 63pp.

Information written by Barry Keller,© 2000
Map image provided by
Stephen Burton,© 2000
Design by Ean Harker©1999, 2000.