Long-eared myotis

Dana Sanchez, Christopher (Digger) Anthony

Latin name: Myotis evotis

Western long-eared myotis are insect-eating bats that occur in numerous vegetation communities and depending on the season, can be found between British Columbia, Canada, through western and southwestern U.S. states, into Baja California, Mexico. Old-growth juniper woodlands in central Oregon offer a challenging environment, with very few trees per acre to provide shade or shelter, high summer temperatures persisting into the nighttime, and low water availability most of the year, including the bat’s breeding and pup-raising season. Regardless of these challenges, bats must find roosts in which to spend the daytime, and this harsh environment is one in which the species’ habits had not been studied. Dr. Sanchez’s graduate student Digger Anthony radiotagged male and female bats during the pup-rearing season, allowing them to learn that lactating females preferred roosts in rock crevices, whereas males selected fairly evenly between crevices in rocks and in old-growth juniper trees. Selection of roosts, regardless of bat sex or type, was strongly influenced by proximity to water. Thus, the results of the study are informing managers to retain standing old-growth juniper trees and rocks, especially near seasonal water sources, in order to help maintain populations of this fascinating bat.

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