Townsend’s long-eared bat

[ CORYNORHINUS TOWNSENDII ]

After living alone all summer, male Townsend’s long-eared bats begin moving to hibernation caves in late October -- but their primary motivation is not readily apparent. Rather than hunkering down for a long winter sleep, the males take up residence in the warmest parts of a cave and await the arrival of up to hundreds of females that cluster in the coldest sections of the cave and quickly fall into a deep sleep. On occasional warm winter days, males rouse themselves for brief feeding flights and their main order of business -- inseminating the dormant females, each of which will be mated multiple times over the course of the winter. Females store sperm until they begin ovulating in the spring, and the first babies are born in May.

NATURAL HISTORY

More than any other Western bat, this species is closely associated with caves and old mining tunnels. Unfortunately, these bats are extremely sensitive to disturbance, and they readily abandon caves when disturbed by humans. Because they have permanently abandoned many important nursery and wintering caves, their populations are increasingly threatened.

KEY CHARACTERISTICS

Widespread in California but nowhere common, the long-eared bat is usually identified by its outrageously long ears.