Hoary Bat (Aeorestes cinereus)

Description: The hoary is a thickly-furred, relatively large bat with the dorsal surface of the (tail) membrane between hind legs and feet densely furred. Ears are rounded with glossy, black, naked edges

Color: Fur color of the back is typically grayish or brownish, heavily frosted with white (hence its name – “hoary”, meaning “gray or white” or “aged”)

Facial portrait of the hoary bat. Photo by Daniel Neal.

Facial portrait of the hoary bat. Photo by Daniel Neal.

North American Range: The species is found throughout North America including most of eastern Canada and most of Mexico outside of its west coast and the Baja peninsula.

Roosting: this is a solitary bat that roosts in trees, often within leaf clusters.


Hoary bat in tree. Photo: By Photographer: Paul Cryan, U.S. Geological Survey

Hoary bat in tree. Photographer: Paul Cryan, U.S. Geological Survey

Characteristics: Hoary bats are very strong fliers. They may use the heavily-furred tail as a blanket during period of cold temperatures

Feeding: Hoary bats typically depart roosts 2-5 hours after sunset. Moths are a common component of the hoary bat’s diet but they may also eat beetles, grasshoppers, termites, dragonflies, and wasps.

Migration: The hoary bat is migratory in some populations (specifically, moving from north to south for the winter months) but transient and/or resident in others (for example, our Central Coast population). In the latter case, some individuals migrate from colder inland areas to more temperate climates along the coast. Hoary Bats are rarely found in winter hibernacula in the U.S. but may be active throughout the year where conditions are favorable.

During spring migration, pregnant females preceding males in their northward journey.

Breeding: Breeding occurs in fall. Typically there are two pups per litter with young typically born in the period between May and July. Males and females typically do not coexist during summer months.