The little brown bat is found from Alaska across Canada and the United States, and as far south as southern California, Arizona, New Mexico, southeastern Oklahoma, northern Alabama, and northern Georgia. During the summer, these bats are usually found in buildings, towers, hollow trees, beneath the loose bark of trees, in crevices of cliffs, and beneath bridges. During winter, these colonial bats move into caves and abandoned mines where they either hang individually or in small clusters of 25 to 30. The little brown bat holds the record for longevity among bats - 32 years (Linzey, 1998). It forages over water, as well as among trees in rather open areas (Harvey et al., 1999).
Species Measurements:
- Adult Total Length: 75-98 mm (3-4 in.)
- Tail: 30-45 mm (1 1/4-1 3/4 in.)
- Hind Foot: 8.5-10 mm (1/4-3/8 in.)
- Weight: 7-10 g (14-1/3 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 little brown bat is brownish in color. The hairs on the back have long, glossy tips that give the pelage a metallic sheen. The underparts are whitish or gray, washed with buff. The ears, wings, and tail membranes are dark brown. The ear reaches to the tip of the nose when laid forward. Hairs on the hind feet extend beyond the toes.
Habitat:
All of the park's caves provide critically important habitats for bats. During the summer, these bats are usually found in buildings, towers, hollow trees, beneath the loose bark of trees, in crevices of cliffs, and beneath bridges. During winter, these colonial bats move into caves and abandoned mines where they either hang individually or in small clusters of 25 to 30.
Reproduction:
Mating occurs in late summer but may also occur during the hibernation period (Harvey et al., 1999). Females store the sperm through winter, and ovulation and fertilization take place in the spring when females tend to congregate in nursery colonies, where each bears a single young about 60 days after fertilization.
Longevity:
The little brown bat holds the record for longevity among bats - 32 years (Linzey, 1998).
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). Little brown bats forage over water, as well as among trees in open areas (Harvey et al., 1999).
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 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:
See "Bat Flea", Myodopsylla insignis (Rothschild); Spinturnicid Mite, Spinturnix americanus (Banks)
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 little brown bat is found from Alaska across Canada and the United States, and as far south as southern California, Arizona, New Mexico, southeastern Oklahoma, northern Alabama, and northern Georgia.
The little brown bat has been recorded from eleven localities in the park and along the Foothills Parkway.
References:
Barbour, R.W. and W.H. Davis. 1969. Bats of America. Lexington: The University Press of Kentucky.
Fenton, M.B. and R.M.R. Barclay. 1980. Myotis lucifugus. Mammalian Species No. 142: 1-8. American Society of Mammalogists.
Fenton, M.B., and G.P. Bell. 1981. Recognition of Insectivorous Bats by their Echolocation Calls. Journal of Mammalogy 62(2): 233-243.
Fenton, M.B. 1999a. Little Brown Bat. Pages 94 - 95. In: D.E. Wilson, and S. Ruff (eds.). The Smithsonian Book of North American Mammals. Smithsonian Institution Press, Washington, D.C.
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.
Tuttle, M.D. 1988. America's Neighborhood Bats. Austin: University of Texas Press.
Animalia
Chordata
Mammalia
Chiroptera
Vespertilionidae
Phenology
(LeConte, 1831)