Eastern red bat

Description

Eastern red bat is a medium-sized, solitary, migratory, tree bat. Adults are densely furred, 3¾″″ to 4⅝″ long, and weigh ¼ to ½ ounce.

The fur (pelage) of the male is brick red. The stiff, long hairs (guard hairs) are white-tipped, giving the fur a frosted appearance. There is a buffy white patch on the front of each shoulder. On females the pelage is often described as yellowish-red but might be more accurately described as dull, buffy, chestnut brown. Unlike most bats, the female has four mammary glands.

The forearm is 17 ⁄16″ to 1⅝″ long.

The wing-like flight membrane (patagium) is composed of skin and associated tissues between the neck and the first digit of the forelimb (propatagium), between the digits of the forelimb (dactylopatagium), between the last digit and the hind limb (plagiopatagium), and between the tail and the hindlimb (uropatagium or interfemoral membrane). The upper side of the interfemoral membrane is densely and completely covered with fur. The underside is thinly furry and just near the base. The patagium is otherwise naked except for thin fur along the humerus and at the wrist.

The tail is relatively long, 1¾″ to 27 ⁄16″, but does not extend beyond the interfemoral membrane. It is hairy on the upper surface. The genus name Lasiurus means “hairy tail”. When in flight the tail and interfemoral membrane are held outstretched, giving a distinctive V-shaped silhouette.

The foot is small, about half the length of the uppermost tarsal bone.

The skull is short and blunt. The ear is short, broad, and rounded. It is not rimmed with black. The projection covering the ear canal (tragus) is triangular and relatively short, about ⅛″ long. It is naked on the inner surface and densely furry on the basal two-thirds of the outer surface. The mouth has 32 teeth. There is a single upper incisor on each side. The first molar-like tooth is tiny and peg-like. It is on the inside (tongue side) of the canine tooth.

Size

Total length: 3¾″″ to 4⅝″

Wingspan: 11½″ to 13″

Tail: 1⅝″ to 2″

Sign

Similar Species

Hoary bat (Lasiurus cinereus) is larger, up to to 5¾″ long. The pelage is brown. The hairs above are strongly white-tipped, giving the bat a hoary appearance.

Silver-haired bat (Lasionycteris noctivagans) pelage is black or dark brown with silvery tips. The upper surface of the interfemoral membrane is lightly furred. The ears are hairless.

Habitat

Woodland openings and edges, hedgerows, tree-lined roads, streams.

Ecology

Behavior

During the day they hang by their feet in in a tree or shrub usually 2′ to 10′ off the ground. They choose a sight with dense foliage above and to the sides but clear below, leaving a clear flight path. They have a single feeding session each day lasting a few hours. They usually begin hunting at dusk, but sometimes later in the night. They locate their prey both by echolocation and by sight. They migrate south in the winter but their wintering range is unknown.

Lifespan

About 12 years

Life Cycle

Males and females have different summer ranges. Though solitary, they come together to migrate in mixed sex flocks of up to several hundred individuals. Mating takes place in August and September during southward migration. The female stores the sperm over the winter, and fertilization occurs the following spring around March and April. After about 90 days she gives birth to usually two or three but up to five young. The young are suckled for about 38 days and take their first flight after about 5 weeks. Those that reach adulthood live about 12 years.

Food

Mostly moths, but also beetles, flies, and other insects.

Disease Vector

Bats are important vectors of the rabies virus but rabid bats pose little threat to humans. They are passive, will not attack, and will not bite unless handled.