Field Guide to Mammals
of Southern California
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Long-Eared Myotis (Myotis evotis)
The long-eared myotis occurs from southwestern Canada, southeast to the Dakotas and through the western United States to Baja California. The species occurs throughout California from sea level to high-elevation forests and up to 9,300 feet (2,830 meters) in Wyoming (Manning and Jones 1989, Philpott 1997). In southern California, it appears to be restricted to high-elevation conifer forests (Stephenson and Calcarone 1999). Long-eared myotis were found only at elevations above 4,000 feet (1,219 meters) during surveys conducted throughout the four southern California national forests (Stephenson and Calcarone 1999).
Two subspecies are recognized (Manning and Jones 1989) with M. e. evotis occupying the majority of the range.
Long-eared myotis occurs largely in forested habitats, such as mixed hardwood/conifer and montane forest in northern California and pinyon-juniper, mesquite shrub, and pine/oak woodland in southern California. It is one of the most abundant bat species in giant sequoia forests (Philpott 1997). The species has also been found in semiarid shrublands, sagebrush, and chaparral (Manning and Jones 1989). Roosting habitat includes abandoned buildings, hollow trees, loose slabs of bark, timbers of unused railroad trestles, bridges, caves and mines, fissures of cliffs, and sink holes (Harvey and others 1999, Stephenson and Calcarone 1999) and one notation of crevices in the ground (Murphy 1994). Broken rock outcrop is important habitat for this species (Manning and Jones 1989). Telemetry studies located roosting M. evotis in road cut rock crevices, buildings and a maternity colony in a ranch building (Miner and Brown 1996).
Long-eared myotis give birth to one young per year, with birth generally occurring in June–July. Maternity colonies are typically small, consisting of fewer than 40 individuals (Philpott 1997).
The long-eared myotis emerges from its day roost at dusk (Harvey and others 1999). Caves and other sheltered locations are used as night resting sites (Manning and Jones 1989). The long-eared myotis is a year-round resident in California and presumed not to migrate. Hibernating individuals have been found in caves in northern California (Philpott 1997).
Diet and Foraging
The diet of long-eared myotis includes moths, small beetles, and flies (Philpott 1997). These bats tend to use a flexible foraging strategy, hunting for prey near vegetation or on the ground (Philpott 1997). This strategy includes catching insects both by aerial pursuit and substrate gleaning (Philpott 1997). Long-eared myotis forage along rivers, streams, over ponds, and within cluttered forest environments (Philpott 1997) using a slow, maneuverable flight (Harvey and others 1999). They are also believed to feed within night roost structures, such as caves and mines, by gleaning moths off the walls (Philpott 1997).
Males and non-pregnant females may occasionally occupy the same site as a maternity colony, but will roost in a different portion of the site, away from the maternity colony itself. Away from the maternity colony, males and non-pregnant females live singly or roost in small groups. Roosts may range in size from 12 to 30 individuals (Harvey and others 1999).
Predators of long-eared myotis include snakes, raccoons, hawks, and owls (Harvey and others 1999).
Arizona Game and Fish Department. 1999. Arizona wildlife views: Special edition. Phoenix, AZ: Arizona Game and Fish Department.
Federal Register. 1994. Endangered and threatened wildlife and plants; Animal candidate review for listing as endangered or threatened species, proposed rule. Department of the Interior. Tuesday, November 15, 1994. 50 CFR Part 17.
Harvey, M.J.; Altenbach, J.S.; Best, T.L. 1999. Bats of the United States. Arkansas: Arkansas Game and Fish Commission.
Manning, R.W.; Jones, J.K., Jr. 1989. Myotis evotis. Mammalian species. No. 329. The American Society of Mammalogists.
Miner, K.; Brown, P. 1996. A report on the southern California forest bat survey and radio telemetry study of 1996.
Murphy, M. 1994. On the track of forest bats. Bats: Vol. 12 No. 2: 4-9.
Philpott, W. 1997. Summaries of the life histories of California bat species. Unpublished document. USDA Forest Service, Sierra National Forest, Pineridge Ranger Station.
Stephenson, J.R.; Calcarone, G.M. 1999. Southern California mountains and foothills assessment: Habitat and species conservation issues. General Technical Report GTR-PSW-175. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture.
Information gathered from California DFG - California Interagency Wildlife Task Group