Townsend’s Big-eared Bat – State Wildlife Action Plan

Townsend’s Big-eared Bat

Townsend's Big-eared Bat
Photo Credit: Don Albright

Townsend’s big-eared bat is a medium sized bat (5-13g) with large ears joined at their base, and large horseshoe-shaped glands on its muzzle. The dorsal hair color has a grey base, and the tips range from pale cinnamon to blackish brown. The ventral hairs are also grey at the base, but the tips range from pale brown to buff. There is some regional variation in color, but generally the species exhibits brown dorsal fur with paler underparts. Females on average are slightly larger than males. Townsend’s big-eared bats have been recorded to live up to 21 years.

Overview

  • Species Common Name Townsend's Big-eared Bat
  • Species Scientific Name Corynorhinus townsendii
  • Federal Listing Status Species of Concern
  • State Listing Status Sensitive

Ecoregions

    Special needs

    Townsend’s big-eared bats are both aerial hawkers and gleaners, specializing on moths, and use open habitats for foraging. This species strongly prefers caves but also uses other cave-like structures including mines, bridges, buildings, and hollowed trees for roosting, rearing young, and hibernating. Townsend’s big-eared bats are extremely sensitive to human disturbance at roosting sites and hibernacula.

    Limiting factors

    Townsend’s big-eared bats gather in concentrations and have highly specific roost requirements (dependence on uncommon or at-risk structures for habitat). This species is very sensitive to disturbance at roost sites. Reductions in their insect prey base and low reproductive rates may be further limiting factors.

    Conservation actions

    • Use gates and seasonal closures to protect known roost sites during sensitive times (raising young and hibernation).
    • Maintain buildings used as roosts.
    • Retain and create large diameter hollow trees during forest management activities.
    • Monitor roosts.

    Key reference or plan

    North American Bat Monitoring Program in the Pacific NW. Read here