Animal Diversity WebU of M Museum of Zoology ADW Home ADW Home ADW Home University of Michigan Help About Aninal Names Teaching Special Topics About Us



Structured Inquiry Search — preview

Myotis sodalis
Indiana bat


By Anna Burgess

Kingdom: Animalia
Phylum: Chordata
Subphylum: Vertebrata
Class: Mammalia
Order: Chiroptera
Family: Vespertilionidae
Genus: Myotis
Species: Myotis sodalis

Geographic Range

Myotis sodalis, also known as the Indiana bat, is found only in North America. Their range spans from Iowa, Missouri, and northern Arkansas east to western Virginia and North Carolina, and north into New York, Vermont, New Hampshire, and Massachusetts. These areas include both their winter hibernation sites and summer ranges. Indiana bats hibernate in the northern reaches of their range in caves during the winter. In the summer and autumn months Myotis sodalis migrate to summer roosting sites. (Kurta, et al., 2002; Thomson, 1982)

Biogeographic Regions
nearctic (Native )

Habitat

Range elevation
0 to 1,746 m
(0.00 to ft)

Average elevation
1,047 m
( ft)

Indiana bats hibernate predominantly in limestone caves, though some hibernate under the bark of dead trees. Cave temperatures range from 3.0 to 7.2 degrees Celsius; warmer temperatures are at the start of the hibernating season in October to November and cooler temperatures during March to April. They roost at elevations from 0 to 1,746 m above sea level (average 1047 m). During the summer, Indiana bats roost under the bark of large trees, under bridges, and sometimes in buildings. Trees in which Indiana bats are known to roost include bitternut hickory (Carya cordiformis), oaks (Quercus), elms (Ulmus), pines (Pinus), American sycamore (Platanus occidentalis), and eastern cottonwood (Populus deltoides). (Barclay and Kurta, 2007; Brack, et al., 2002; Butchkoski and Hassinger, 2002; Gardner and Cook, 2002; Tuttle and Kennedy, 2002)

Habitat Regions
temperate ; terrestrial

Terrestrial Biomes
forest ; mountains

Other Habitat Features
caves

Physical Description

Range mass
5 to 11 g
(0.18 to 0.39 oz)

Range length
70.8 to 90.6 mm
(2.79 to 3.57 in)

Average length
81.7 mm
(3.22 in)

Range wingspan
240 to 267 mm
(9.45 to 10.51 in)

Indiana bats are small, weighing approximately 7 g with a forearm range of 35 to 41 mm. They are dark grey or brown in color and their fur is considered soft. They are distinguished from other, similar, co-occuring members of M. myotis by their distinctly keeled calcar, a small cartilage projection from the foot, giving added stability to the wing. Indiana bat fur is soft in comparison to that of the very similar and closely-related little brown bat, Myotis lucifugus, which has fur that tends to be more shiny. Male and female Indiana bats are very similar with the female tending to be a little larger than the male. (Barbour and Davis, 1969; Whitaker and Hamilton, 1998)

Other Physical Features
endothermic ; heterothermic ; bilateral symmetry

Sexual Dimorphism
female larger

Reproduction

Indiana bats are polygynous, with one male mating with multiple females. Males wait at the entrance to winter hibernacula for the opportunity to copulate with un-mated females. This occurs during the "fall swarming" period in October or November. There have been some accounts of Indiana bats copulating in late winter or early spring but this is rare. (Whitaker and Hamilton, 1998)

Mating System
polygynous

Breeding interval
Indiana bats breed once yearly.

Breeding season
Copulation generally occurs in October, before hibernation.

Range number of offspring
1 to 2

Average number of offspring
1

Average number of offspring
1
[External Source: AnAge]

Range gestation period
68 (high) days

Range weaning age
25 to 37 days

Range time to independence
2 to 3 months

Myotis sodalis copulate in the fall, generally in late October. This is the time right before they enter into hibernation. Pregnancy does not begin at this time, as the females can store sperm over winter. This delayed fertilization allows the young to be born in summer (up to 68 days post fertilization). Females give birth to only one pup (on rare occasions twins) per year. Most pups are born between late June and early July with weaning at about 31 days (range 25 to 37 days). The first born of the season may be volant as early as mid-July. (Barbour and Davis, 1969; Barnard, 2009; Fenton, 1985; Whitaker and Hamilton, 1998)

Key Reproductive Features
iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); induced ovulation ; fertilization ; viviparous ; delayed fertilization

Females provide care for pups after birth at summer roosting sites. Often maternity colonies are formed and male presence is rare. Females are responsible for providing nourishment for their pups through lactation. Time to weaning is about 31 days and pups are fully independent from their mothers in 2 to 3 months. (Whitaker and Hamilton, 1998)

Parental Investment
altricial ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)

Lifespan/Longevity

Range lifespan
Status: wild

20 (high) years

Typical lifespan
Status: wild

15 (high) years

Myotis sodalis individuals have been documented to live 20 years in the wild, but have an expected lifespan of 15 years in the wild. (Miller and Allen, 1928)

Behavior

Range territory size
2 to 8 m^2

Indiana bats are social, which may account for their alternate common name, "social myotis." There have been no documented cases of social hierarchies within the species. Males and females hibernate together, but adults separate in the summer months. Maternity colonies contain juvenile males and only rarely adult males. They migrate seasonally; to travel from winter hibernacula to summer roosts Indiana bats travel distances up to thousands of kilometers. For example, a banded female caught by mist netting over a river in southern Iowa that had come from a hibernaculum in Missouri.

They have a wide nocturnal foraging area during the summer months. Perhaps this is why the area of suitable summer habitat does not correspond to population densities for this bat. For example, in a forest of up to 5 million hectares, population estimates were small as 10,000 bats. Another area of forest covering 1.7 million hectares was estimated to have 112,500 Indiana bats. (Gardner and Cook, 2002; Pierson, 1998; Whitaker and Hamilton, 1998)

Key Behaviors
troglophilic; flies; nocturnal ; crepuscular ; migratory ; hibernation ; social ; colonial

Home Range

Home range size of Indiana bats varies by individual as well as time of year. They are an average of 625 ha during the fall, and 255 +/- 89 ha in the spring. These home ranges are not defended. Perhaps the only territory defended is a space within a maternity colony or a hibernaculum, where bats might interact with individuals within 5 square meters of themselves. (Romme, et al., 2002; Whitaker and Hamilton, 1998)

Communication and Perception

Indiana bats, like other insectivorous bat species, use echolocation to maneuver through their various habitat types. They have well-developed eyesight which they use to aid with their travels from their winter hibernacula to their summer roosting sites. We can assume that Myotis sodalis individuals do communicate with each other using sound, but there have been no studies to further investigate this. Like other mammals, it is likely that these bats use chemical cues to communicate reproductive state. (Linzey, 2001)

Communication Channels
visual ; acoustic ; chemical

Perception Channels
visual ; echolocation

Food Habits

Myotis sodalis individuals consume a diet of insects. A study found that Indiana bats eat insects from five main taxa: Coleoptera (beetles), Diptera (flies), Hymenoptera (bees, wasps), Lepidoptera (butterflies and moths), and Trichoptera (caddisflies). There are also differences in what females eat based on whether they are pregnant or lactating or neither. Lactating females eat greater amounts of coleopterans and trichoperans compared to non-lactating female bats. There are slight differences in diet based on location; southern colonies feed more on terrestrial insect species, whereas more northern bats fed on insects around wetlands. (Linzey, 2001; Murray and Kurta, 2002)

Primary Diet
carnivore (Insectivore )

Animal Foods
insects

Predation

Known Predators


Predators of Indiana bats include carnivorous animals such as snakes, owls, raccoons (Procyon lotor), and other medium-sized mammals. The main adaptations Indiana bats have against predation is that they roost in caves and inaccessible tree crevices, putting them out of reach of many predators. They are also active at night and agile in flight. Myotis sodalis individuals hibernate in large clusters which help ensure survival (and warmth) between October and April. Their cryptic coloration also helps to protect them from predation.

Humans have been known to kill these bats, although they are not eaten. For example, at Carter Caves State park in Kentucky, two men clubbed 105 Indiana bats to death. Humans also unintentionally kill bats by destroying or cutting down summer roost trees or disturbing hibernation sites. (Hart, 2010; Mohr, 1976; Whitaker and Brack, 2002; Whitaker and Hamilton, 1998)

Anti-predator Adaptations
cryptic

Ecosystem Roles

Indiana bats help control insect populations and are prey for bat predators. Indiana bats act as hosts for species of mites (Steatonyssus occidentalis and Macronyssus crosbyi) but there have been no documented intestinal parasites. Indiana bats have a direct impact on their cave environment by adding nutrients to the cave with their guano and decomposing bodies. (LaRoe, et al., 1995; Whitaker and Mumford, 1971; Whitaker, 1973)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

Indiana bats may impact humans by helping to control pest insect populations. (Whitaker and Hamilton, 1998)

Positive Impacts
controls pest population

Economic Importance for Humans: Negative

Indiana bats can become a nuisance in some places where their summer roots have been destroyed due to increasing human populations. Bats will then find their way into homes and attics to roost. Like most mammals in the United States, Indiana bats also may be carriers of rabies. However, documented incidence of rabies infection in Indiana bats is low. It is also very unlikely that humans will come into close contact with Indiana bats for the disease to be transmitted. If you come into contact with a bat or other wild mammals, you should see a doctor to receive immunizations that will protect you from this potentially fatal disease. (Butchkoski and Hassinger, 2002)

Negative Impacts
injures humans (carries human disease)

Conservation Status

IUCN Red List of Threatened Species [Link]
Endangered
More Information

US Federal List [Link]
Endangered

CITES [Link]
No special status

State of Michigan List [Link]
Endangered

Indiana bats are a federally-endangered species and recovery plans are in place to monitor the health of this species throughout its range. For example, any organization intending to significantly alter a habitat within the range of this species is required by law to conduct surveys. If an Indiana bat roost is located within the area to be altered, plans must accommodate this individual (or group of individuals).

Temperate North American bats, including Indiana bats, are now threatened by a fungal disease called “white-nose syndrome.” This disease has devastated eastern North American bat populations at hibernation sites since 2007. The fungus, Geomyces destructans, grows best in cold, humid conditions that are typical of many bat hibernacula. The fungus grows on, and in some cases invades, the bodies of hibernating bats and seems to result in disturbance from hibernation, causing a debilitating loss of important metabolic resources and mass deaths. Mortality rates at some hibernation sites have been as high as 90%. Currently, there is no known cure for white nose syndrome.

Humans also impact Indiana bats by entering their hibernacula for recreational caving. This can disturb bats while they are hibernating and cause them to wake up when there is no food available for them. Many Indiana bat hibernacula have been closed off to humans and a bat-friendly gate placed at the entrance to limit human intrusion. ("Indiana Bat (Myotis sodalis) Draft Recovery Plan: First Revision", 2007; Gargas, et al., 2009)

For More Information

Find Myotis sodalis information at

Contributors

Anna Burgess (author), Radford University, Gail McCormick (editor), University of Michigan, Karen Francl (editor), Radford University, Tanya Dewey (editor), University of Michigan.

References

U.S. Fish and Wildlife Service. Indiana Bat (Myotis sodalis) Draft Recovery Plan: First Revision. Fort Snelling: Fort Snelling. 2007.

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

Barclay, R., A. Kurta. 2007. Ecology and Behavior of Bats Roosting in Tree Cavities and Under Bark. Pp. 17-50 in M Lacki, J Hayes, A Kurta, eds. Bats in Forests: Conservation and Management. Baltimore: The Johns Hopkins University Press.

Barnard, S. 2009. Maintaining Bats for Captive Study. Pp. 351 in T Kunz, S Parsons, eds. Ecological and Behavioral Methods for the Study of Bats. Baltimore: The Johns Hopkins University Press.

Brack, V., C. Stihler, R. Reynolds, C. Butchkoski, C. Hobson. 2002. Effect of Climate and Elevation on Distribution and Abundance in the Midestern United States. Pp. 21-28 in A Kurta, J Kennedy, eds. The Indiana Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

Butchkoski, C., J. Hassinger. 2002. Ecology of a Maternity Colony Roosting in a Building. Pp. 130-142 in A Kurta, J Kennedy, eds. The Indiana Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

Clawson, R. 2002. Trends in Population Size and Current Status. Pp. 2-8 in A Kutra, J Kennedy, eds. The Indiand Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

Currie, R. 2002. Response to Gates at Hibernacula. Pp. 86-99 in A Kurta, J Kennedy, eds. The Indiana Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

Fenton, M. 1985. Communication in the Chiroptera. Bloomington: Indiana University Press.

Gardner, J., E. Cook. 2002. Seasonal and Geographic Distribution and Quantification of Potential Summer Habitat. Pp. 9-20 in A Kurta, J Kennedy, eds. The Indiana Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

Gargas, A., M. Trest, M. Christensen, T. Volk, D. Blehert. 2009. Geomyces destructans sp. no. associated with bat white-nose syndrome. Mycotaxon, 108: 147-154.

Hallam, T., P. Federico. 2009. Application of Dynamic Population Models to Bats. Pp. 184 in T Kunz, S Parsons, eds. Ecological and behavioral methods for the study of bats. Baltimore: The Johns Hopkins University Press.

Handley Jr., C. 1991. Virginia's Endangered Species. Blacksburg, Virginia: The McDonald and Woodward Publishing Company.

Hart, K. 2010. "Bat killers sentenced in federal court" (On-line). Accessed December 01, 2010 at http://dailyindependent.com/local/x434655806/Bat-killers-sentenced-in-federal-court.

Kiser, J., J. MacGregor, H. Bryan, A. Howard. 2002. Use of Concrete Bridges as Nightroosts. Pp. 208-215 in A Kurta, J Kennedy, eds. The Indiana Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

Kurta, A., S. Murray, D. Miller. 2002. Roost Selection and Movements Across the Summer Landscape. Pp. 118-129 in A Kurta, J Kennedy, eds. The Indiana Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

LaRoe, E., G. Farris, C. Puckett, P. Doran, M. Mac. 1995. Our Living Resources: a report to the nation on the distribution, abundance, and health of U.S. plants, animals, and ecosystems. Washington DC: U.S. Department of the Interior, National Biological Service.

Linzey, D. 2001. Vertebrate Biology. New York: McGraw-Hill.

Miller, , Allen. 1928. Indiana Myotis: Myotis Sodalis. Pp. 205-211 in M Trani, W Ford, B Chapman, eds. The Land Manager's Guide to Mammals of the South. Durham, NC: USDA Forest Service, Southern Region and The Nature Conservancy.

Mohr, C. 1976. The World of the Bat. Philadelphia and New York: J. B. Lippincott Company.

Murray, S., A. Kurta. 2002. Spatial and Temporal Variation in Diet. Pp. 182-192 in A Kurta, J Kennedy, eds. The Indiana Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

Pierson, E. 1998. Tall Trees, Deep Holes, and Scarred Landscapes: Conservation Biology of North American Bats. Pp. 312-313 in T Kunz, P Racey, eds. Bat Biology and Conservation. Washington and London: Smithsonian Institution Press.

Romme, R., A. Henry, R. King, T. Glueck, K. Tyrell. 2002. Home Range Near Hibernacula in Spring and Autumn. Pp. 153-164 in A Kurta, J Kennedy, eds. The Indiana Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

Thomson, C. 1982. Myotis sodalis. Mammalian Species, 163: 1-5.

Tuttle, M., J. Kennedy. 2002. Thermal Requirements During Hibernation. Pp. 68-78 in A Kurta, J Kennedy, eds. The Indiana Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

Viele, D., A. Kurta, J. Kath. 2002. Timing of Nightly Emergence. Pp. 199-207 in A Kurta, J Kennedy, eds. The Indiana Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

Whitaker, J. 1973. External Parasites of Bats of Indiana. The Journal of Parasitology, 59/6: 1148-1150.

Whitaker, J., V. Brack. 2002. Distribution and Summer Ecology in Indiana. Pp. 48-54 in A Kurta, J Kennedy, eds. The Indiana Bat: Biology and Management of an Endangered Species. Austin, Texas: Bat Conservation International.

Whitaker, J., W. Hamilton. 1998. Mammals of the Eastern United States. Cornell University Press: Comstock Publishing Associates.

Whitaker, J., R. Mumford. 1971. Notes on a COllection of Bats Taken by Mis-Netting at an Indiana Cave. American Midlans Naturalist, 85/1: 277-279.

Whitaker, J., C. Ritzi, C. Dick. 2009. Collecting and Preserving Bat Ectoparasites for Ecological Study. Pp. 813 in T Kunz, S Parsons, eds. Ecological and Behavioral Methods for the Study of Bats. Baltimore: The Johns Hopkins University Press.

To cite this page: Burgess, A. 2011. "Myotis sodalis" (On-line), Animal Diversity Web. Accessed May 22, 2012 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Myotis_sodalis.html

Disclaimer: The Animal Diversity Web is an educational resource written largely by and for college students. ADW doesn't cover all species in the world, nor does it include all the latest scientific information about organisms we describe. Though we edit our accounts for accuracy, we cannot guarantee all information in those accounts. While ADW staff and contributors provide references to books and websites that we believe are reputable, we cannot necessarily endorse the contents of references beyond our control.

Other formats: OWL

Home  ¦  About Us  ¦  Special Topics  ¦  Teaching  ¦  About Animal Names  ¦  Help

Structured Inquiry Search — preview