Distinguishing Features
Quite easily identified because
of its unusually long ears, Townsend's Big-eared Bat is about 4
inches (10 cm) long with a wing-spread of about 11 inches (28 cm)
The muzzle is naked and black with a pair of large, rather grotesque
glandular lumps behind the nostrils. The short, silky coat is pearly
grey above and light tan beneath (Banfield, 1974).
Distribution
Columbia Basin: Creston and Cranbrook
areas.
British Columbia: Restricted to
the lowlands of southern Vancouver Island, the Gulf Islands, the
Fraser Valley, and the Southern Interior north to the Williams Lake
area. There are also records from Creston and Cranbrook areas.
Global: Mexico, the western United
States, and British Columbia, as well as a few isolated populations
in central and eastern United States.
Habitat
Although the Townsend's Big-eared
Bat occurs in a wide variety of habitats, its distribution is strongly
correlated with availability of caves or cave-like roosts.
Threats
Sparsely distributed through much
of the lowlands of southern British Columbia. Distribution coincides
with intensively developed regions. Very sensitive to disturbance
at hibernacula and nursery colonies (Cannings et al. 1999).
Biology
Diet consists primarily of small moths, but these
bats will also eat lacewings, beetles, flies and sawflies. Mating
occurs in November through February in the hibernaculum. Townsend's
Big-eared Bats are relatively sedentary, and may only move 10-65
km from the winter to the summer roost, where females form maternity
colonies of a dozen to several hundred, and give birth to their
single young after gestation of 50-100 days. They form tightly packed
clusters in order to reduce heat loss and thus promote rapid development
of the young. Males will roost alone during the summer, away from
the females (Cannings et al. 1999).
