|General bat anatomy displayed on a board in the Kentucky Mine Historic Park: the distinct Townsend's big-eared bat has horseshoe-shaped lumps on the nostrils and long ears joining at the base|
Townsend's big-eared bats are named for their extremely long and flexible ears. But there is more in the long common name. The species name—also the shorter scientific name—commemorates the American naturalist and collector John Kirk Townsend (1809-1851), who, in the first half of the 19th century, explored the wildlife between the Rockies and the Pacific Ocean . Various subspecies are found throughout western North America between British Columbia and Mexico.
|Corners and crevices of the stamp mill at the historic Kentucky Mine serve as roosting sites for Townsend's big-eared bats|
Female Townsend's big-eared bats rear their young in maternity colonies. A handout provided at the Kentucky Mine Museum in the Bigelow House describes their mating and breeding cycle:
Mating begins in the fall and continues through the winter. Townsend's big-eared bats have delayed fertilization, storing sperm until ovulation occurs in the spring. In March or April the females begin to form maternity colonies, where theyr rear their young. During the maternity season, males remain solitary or form small bachelor groups. The length of gestation varies depending on the climate, but generally lasts between 56 to 100 days. Females give birth to a single young, called a pup. The babies develop rapidly: they are able to fly by three weeks, nearly grown by four weeks and weaned by six weeks. Females return to the same roost where they were raised to give birth to their own young. Males and females spend the winter together to hibernate.
References and suggested reading Bo Beolens, Michael Watkins and Michael Grayson: The Eponym Dictionary of Mammals. The Johns Hopkins University Press, Baltimore, Maryland, 2009; page 416.
 Noah Greenwald: Townsend's Big-eared Bat Protected Under California Endangered Species Act. Center for Biological Diversity, June 27, 2013. Link: www.biologicaldiversity.org/news/press_releases/2013/townsends-big-eared-bat-06-27-2013.html.
 Gary M. Feller and Elizabeth D. Pierson: Habitat Use and Foraging Behavior of Townsend's Big-Eared Bat (Corynorhinus Townsendii) in Coastal California. Journal of Mammology, February 2002, 83 (1), 167-177. Link: https://academic.oup.com/jmammal/article/83/1/167/2372774.