Species: Corynorhinus townsendii

Townsend's Big-eared Bat

Species

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Species of concern in the Puget Sound watershed

Encyclopedia of Puget Sound

Very large ears, 30-39 mm, joined across forehead; dorsal hairs slate or gray with pale cinnamon brown to blackish brown tips that contrast little with the base; ventral hairs slate, gray, or brownish, with brownish or buff tips; two large fleshy lumps on snout; hairs on toes do not project beyond toenails; total length 90-112 mm; forearm 39.2-47.6 mm; greatest length of skull 15.2-17.4 mm; 36 teeth; adult mass 5-13 g (Handley 1959, Hall 1981, Kunz and Martin 1982, Ingles 1965).

Articles:

Report: Washington State Bat Conservation Plan

May 18, 2013

The Washington Department of Fish and Wildlife recently released a Bat Conservation Plan for the 15 species of bats found in Washington State. All but four of these species occur within the greater Puget Sound watershed1, including:

Fringed Myotis. Photo © Merlin D. Tuttle, Bat Conservation International, www.batcon.org

Townsend's Big-eared Bat (Corynorhinus townsendii)

August 01, 2013

This article was originally published by the Washington Department of Fish and Wildlife as part of its annual report Threatened and Endangered Wildlife in Washington.

Townsend's big-eared bat. Photo by Bat Conservation International.

Classification

Kingdom

Animalia

Phylum

Craniata

Class

Mammalia

Order

Chiroptera

Family

Vespertilionidae

Genus

Corynorhinus

NatureServe

Source:
ELEMENT_GLOBAL.2.103228

Classification

Other Global Common Names

Un Murciélago - oreillard de Townsend

Informal Taxonomy

Animals, Vertebrates - Mammals - Bats

Formal Taxonomy

Animalia - Craniata - Mammalia - Chiroptera - Vespertilionidae - Corynorhinus - as the appropriate genus for New World big-eared bats.

Ecology and Life History

Short General Description

A big-eared bat.

Migration

true - false - false - In Oregon, individuals moved up to 24 km from hibernacula to foraging areas (Dobkin et al. 1995). In Marin County, California, foraging individuals traveled up to 10.5 kilometers from primary day roost (site of maternity colony, but the study was conducted in September after nursery period had ended), and they tended to forage in the same areas each night. The mean center of activity for females was 3.2 +/- 0.5 kilometers from the roost, whereas the mean center of activity for males was only 1.3 kilometers from the roost. Between 41 and 88 percent of tagged bats returned to the roost each night; nine alternate roosts were located, all used by single bats (Fellers and Pierson 2002).

Non-migrant

true

Locally Migrant

false

Food Comments

Feeds on various flying insects near the foliage of trees and shrubs. May feed primarily on moths (Barbour and Davis 1969). In a California study, individuals hunted primarily around the perimeter of trees, usually 10-30 m off the ground, between mid-canopy and near the top of the canopy (Fellers and Pierson 2002).

Reproduction Comments

Mating begins in autumn, continues into winter. Ovulation and fertilization are delayed until late winter/early spring. Gestation lasts 2-3.5 months. Litter of one is born in late spring/early summer (beginning mainly in late May in California, the second week of July in Washington, and June in southwestern Texas). Throughout the U.S. range, the earliest births occur in mid-April, the latest in late July (see Handley 1959). Young can fly at 2.5-3 weeks, weaned by 6 weeks. Females are sexually mature their first summer. Males are not sexually active until their second year (California). Young fly at 1 month of age, weaned at 2 months. Nearly all adult females breed every year. Females commonly form nursery colonies generally of up to about 200 (west) or 1000 (east), but solitary pregnant females are frequently encountered (Handley 1959); males roost separately (apparently solitary) during this time.

Ecology Comments

Crude population density in Oklahoma was estimated at one bat per 46.6 sq km (see Kunz and Martin 1982), about 3-4 times greater than that reported for populations in California (Pearson et al. 1952). Hibernates singly, or in clusters in some areas (Caire et al. 1989, Schmidly 1991). Tends not to associate in daytime and hibernation roosts with other species of bats, though scattered individuals of other normally colonial species occasionally may be present (Handley 1959). Pre-weaning post-natal mortality generally is low. Adult survivorship is relatively high (about 70-80% in females in California). Predation has been suggested as the primary limiting factor in Kansas and Oklahoma (see Handley 1959). Pearson et al. (1952) believed that a population increase might be dependent on the establishment of new nursery colonies (colonies remained static in size year after year); how new nursery colonies become established is not known (Handley 1959).

Length

Weight

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

1996-11-05

Global Status Last Changed

1996-11-05

Distribution

Conservation Status Map

Global Range

H - >2,500,000 square km (greater than 1,000,000 square miles) - H - Range includes western North America from British Columbia south to the Isthmus of Tehuantepec, eastward to the Black Hills of South Dakota, across western Texas, and eastward to the Edwards Plateau. Isolated populations exist in the gypsum caves of northeastern Texas, Oklahoma, and Kansas, and in limestone regions of Arkansas, Missouri, Illinois, Indiana, Ohio, Kentucky, Virginia, and West Virginia. Elevational range extends from near sea level to at least 3,300 meters in some areas.

Global Range Code

Global Range Description

>2,500,000 square km (greater than 1,000,000 square miles)

ELEMENT_GLOBAL.2.103228