The hoary bat is the most widely distributed bat in North America (Tuttle, 1988). It is a tree-roosting bat. During the summer, it is "normally" found in areas of northern coniferous forests where it roosts in hemlock, spruce, and fir trees. It migrates to warmer regions in the fall. The hoary bat is a strong and rapid flier, and is usually the last bat to appear in the evening since it does not usually leave its roost until well after sundown. The hoary bat may live 12 to 14 years in the wild.

Species Measurements:
- Adult Total Length: 130-150 mm (5 1/8-6 in.)
- Tail: 50-63 mm (2-2 1/2 in.)
- Hind Foot: 6-14 mm (1/4-5/8 in.)
- Weight: 21-40 g (3/4-1 1/2 oz.)

Physical Characteristics:
Bats are unique among mammals because their forelimbs are specialized for true flight. Flight membranes, which are actually extensions of the skin of the back and belly, connect the body with the wings, legs, and tail. Unlike birds, bats use both legs and wings during flight. Other modifications for flight include greatly elongated fingers to provide support for the wing membrane, a keeled sternum for the attachment of the enlarged flight muscles, and fusion of some vertebrae. The membrane extending from the tail to the hind legs is known as the interfemoral membrane. The pelage of the large hoary bat is composed of a mixture of yellowish-brown, deep brown, and white hairs. Most of the dorsal hairs are tipped with white, thus giving this bat a distinct silver (hoary) frosting. The margins of the broad, rounded ears are rimmed with dark brown or blackish-brown. A distinct patch of whitish fur is present near the base of the forearm. The dorsal surface of the interfemoral membrane is densely furred.

Habitat:
The hoary bat is usually found in forested areas where it roosts in trees. During the summer, it is normally found in areas of northern coniferous forests where it roosts in hemlock, spruce, and fir trees. In the fall, it migrates to warmer regions.

Reproduction:
The hoary bat mates during the autumn migration, but implantation is delayed until spring. An average of two young are born between mid-May and early July.

Longevity:
The hoary bat may live 12 to 14 years in the wild.

Terrestrial Ecology:
The senses of sight and hearing are well developed in bats. Since most bats become active near dusk, and are active much of the night, sight is of little importance in navigation and in the capture of prey. Instead, they use echolocation, a system somewhat similar to radar. They emit ultrasonic calls, far above the range of human hearing, that are reflected from objects ahead of them. They hear the echoes, and are able to avoid obstacles and find food in total darkness. Different species can be distinguished by differences in the structure of their echolocation calls (Fenton and Bell, 1981).

The hoary bat is a strong and rapid flier. It is usually the last bat to appear in the evening since it does not usually leave its roost until well after sundown. During feeding maneuvers, the tail and wing membranes are used to capture and restrain prey. Some insects are captured by the tail membrane, which forms a pouch-like compartment. The bat must bend its head forward in order to grasp the insect with its teeth and take it into its mouth. Sometimes the bat may use its mouth to capture an insect from its wing.

Eleven species of bats have been recorded in the park and all feed exclusively on insects. During the colder months when flying insects are unavailable, bats must either hibernate or migrate to warmer areas. Eight of the species found in the park are known to hibernate. Only three - the Eastern red bat, hoary bat, and the silver-haired bat - are migratory. Bats are seen flying over the park during every month of the year. However, when flying during the winter, they do not feed.

Predators and Defense:
No predators recorded from the park.

Parasites:
None recorded from the park.

Transmittable Diseases:
Bats are capable of transmitting two diseases to humans - rabies and histoplasmosis. Histoplasmosis is a disease caused by inhaling dust that contains contaminated spores. Tuttle (1988) stated: "Less than a half of 1 percent of bats contract rabies, a frequency no higher than that seen in many other animals. Like others, they die quickly, but unlike even dogs and cats, rabid bats seldom become aggressive." Bats do not attack when they get rabies; they just lie in one place. Although it is rare for humans to contract rabies from infected bats, persons handling them should be aware of this possibility.

The hoary bat is the most widely distributed bat in North America (Tuttle, 1988). It ranges from southern Mexico throughout most of the United States and into Canada. It is apparently uncommon in the southern part of the United States, and is absent from peninsular Florida. The hoary bat is a tree-roosting bat. During the summer, it is "normally" found in areas of northern coniferous forests where it roosts in hemlock, spruce, and fir trees. It migrates to warmer regions in the fall.

The hoary bat is widely distributed but difficult to observe because of its solitary tree-dwelling habits. Rick Varner, a biologist technician in the park, reported observing a live hoary bat in a small cave in Whiteoak Sink in 1988-1989 (Varner, personal communication, 1993). On September 24, 1992, a male hoary bat was found dead at the home of Lucinda Ogle on Ski Mountain Road in Gatlinburg. This property is adjacent to the park boundary.

References:

Barbour, R.W. and W.H. Davis. 1969. Bats of America. Lexington: The University Press of Kentucky.

Fenton, M.B. 1999a. Red Bat. Pages 105-106. In: D.E. Wilson, and S. Ruff (eds.). The Smithsonian Book of North American Mammals. Smithsonian Institution Press. Washington, D.C.

Fenton, M.B., and G.P. Bell. 1981. Recognition of Insectivorous Bats by their Echolocation Calls. Journal of Mammalogy 62(2): 233-243.

Harvey, M.J., J.S. Altenbach, and T.L. Best. 1999. Bats of the United States. Little Rock: Arkansas Game and Fish Commission.

Linzey, D. W. 1995a. Mammals of Great Smoky Mountains National Park. The McDonald & Woodward Publishing Company, Inc., Blacksburg, Virginia.

Linzey, D. W. 1995b. Mammals of Great Smoky Mountains National Park-1995 Update. Journal of the Elisha Mitchell Scientific Society 111(1): 1-81.

Linzey, D. W. 1998. The Mammals of Virginia. The McDonald & Woodward Publishing Company, Inc., Blacksburg, Virginia.

Shump, K.A., Jr. and A.V. Shump. 1982. Lasiurus cinereus. Mammalian Species No. 185: 1-5. American Society of Mammalogists.

Tuttle, M.D. 1988. America's Neighborhood Bats. Austin: University of Texas Press.