Bats of Colorado > Townsend's big-eared bat (Corynorhinus townsendii)
The Townsend?s big-eared bat can be distinguished from all other vespertilionids by the presence of prominent, bilateral nose lumps and very large ears (30?38mm). It also has a well developed tragus. It is a medium sized bat with a brown to grayish brown coloration. The measurements of the Townsend?s big-eared bat as reported by Armstrong at el. (2011) are: total length of 90?112 mm; length of tail 35?54 mm; length of forearm 39?48 mm; wingspan of 30?34 mm; weight of 9?14g.
The Townsend?s big-eared bat occurs throughout the West, and is distributed from the southern portion of British Columbia south along the Pacific coast to central Mexico (C. t. pallenescens, C. t. mexicanus, and C. t. townsendii) and east into the Great Plains (C. t. ingens; endangered), with isolated populations occurring in the southeastern and eastern U.S. (C. t. virginianus; endangered). It has been reported in a wide variety of habitat types ranging from sea level?3300 m. Habitat associations include: coniferous forests, mixed mesophytic forests, deserts, native prairies, riparian communities, active agricultural areas, and coastal habitat types.
The Townsend's big-eared bat has been reported in a wide variety of habitat types ranging from sea level?3300 m. Habitat associations include: coniferous forests, mixed mesophytic forests, deserts, native prairies, riparian communities, active agricultural areas, and coastal habitat types.
Summer maternity colonies range in size from a few dozen to several hundred individuals. Maternity colonies form between March and June (based on local climactic factors), with a single pup
born between May and July. Males remain solitary during the maternity period. Winter hibernating colonies are composed of mixed-sexed groups that can range in size from a single individual to colonies of several hundred animals (or in some areas, particularly in the eastern US, several thousand). Mating generally takes place between October and February in both migratory sites and hibernacula.
Foraging associations include edge habitats along streams, adjacent to and within a variety of
wooded habitats. It often travels large distances while foraging, including movements of over 10 miles during a single evening. It is a moth specialist with over 90% of its diet composed of members of the Order Lepidoptera.
