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Hoary Bat

Lasiurus cinereus


The hoary is a fairly large and distinctly marked bat with long, narrow wings. It is 5-6 inches long, has an average wingspan of about 17 inches, and weighs up to 1.25 ounces; females are slightly larger than males. The coloring of the dorsal area is a mixed brown-gray with a heavy white tinge, giving these bats a frosty ("hoary") appearance. There is a distinctive yellowish-brown collar under its chin and the yellowish ears are edged in black. There are also distinctive white patches on the shoulders and wrists.

hoary bat

Distribution and Habitat

The most widespread of all bats in the Americas, the hoary ranges from Argentina and Chile northward to the tree line of Canada. It is the only bat found in Hawaii, and there are records of migrant hoary bats on Southampton Island off of Northern Canada, and from Iceland, Bermuda, and the Orkney Islands off Scotland. Some hoary populations migrate to southern California, southeastern United States, Mexico, and Guatemala from late October to late November and from February through early May, while others remain north and hibernate for the winter.

Hoary bat habitat varies somewhat depending on geographic region, but diverse forest habitats with a mixture of forest and small open areas that provide edges appear to be the most preferred.


Moths and beetles make up the majority of the hoary bat's diet, but it also feeds on flies, small wasps and their relatives, grasshoppers, termites, and dragonflies. The bat approaches the insect from behind, taking the abdomen and thorax in its mouth and biting off and swallowing this area of the insect, while dropping the wings and head.


The hoary bat is thought to mate around the time of autumn migration, but delayed fertilization delays birth until sometime between mid-May and early-June. Although a mother can have as many as four pups, most litters consist of two. Mothers give birth while hanging upside down in the leafy shelter of their daytime retreat. The hoary bat's ears and eyes are closed at birth and open on days three and twelve, respectively. Purposeful flight is possible by the thirty-third day. The young cling to the mother in the day, while she sleeps, and hang on a twig or leaf while she hunts at night.

Based on litter size, these bats are assumed to be relatively short-lived, most probably living no more than 6 or 7 years.

Other Behaviors

Unlike most bats, the hoary is solitary, except during migration and for breeding.They do, however, often form groups when hunting for insects. Feeding is also the only time that hoary bats appear to associate with other bat species.

Hoary bats reach their peak activity at about five hours after sunset, although they may occasionally be seen flying on warm winter afternoons.

Their flight is stong and direct, reaching speeds of thirteen miles per hour. While hunting, they soar and glide. They forage about the tree tops, along streams and lake shores, and in urban areas where there are lots of trees, stopping to rest between meals.

Hoary bats are highly territorial, choosing feeding sites which they return to night after night.

The hoary is one of the very few vespertilionid bats which makes an audible chatter during flight.

Scientific Classification

Phylum Chordata
Subphylum Vertebrata
Class Mammalia
Order Chiroptera
Family Vespertilionidae
Genera & Species Lasiurus cinereus

Animal Diversity Web
Texas Parks and Wildlife Department

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The Robinson Library >> Science >> Zoology >> Mammals >> Order Chiroptera

This page was last updated on May 17, 2017.