Indiana , Page 1 Myotis sodalis Miller and Allen Indiana bat

State Distribution

Best Survey Period Photo by Merlin D. Tuttle, Bat Conservation International Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Status: Federal endangered, State endangered observations have been reported for 12 counties (see distribution map) (MNFI 2001). A lactating female Global and state rank: G2/S1 caught in 1978 (Kurta 1980) supplied the first evidence that the species reproduces in the state. A nursery Family: (Plain-nosed ) colony was located in riparian habitat along the Thornapple River in Eaton County in 1991; a second Total Range: The Indiana bat summers throughout maternity colony was located along the River Raisin in much of the eastern half of the United States, although it Washtenaw County in 1995; and a third was located does not occur in Canada. Breeding, as determined by along the River Raisin in Lenawee County in 2001. An observations of lactating females or young in summer, intensive 1986 study of the distribution of bats in the has been documented in Illinois, Indiana, Iowa, central Lower Peninsula (an area from Muskegon to , Michigan, Missouri, New York, Ohio and Saginaw counties north to Manistee and Iosco counties) Tennessee. Other eastern states have summer records did not locate the Indiana bat (Kurta et al. 1989). Likely but lack confirmed evidence of breeding. In winter, the the bat is still under-surveyed in Michigan so there is majority of the population congregates in a limited potential for additional occurrences in suitable habitat number of mines and caves, primarily in the karst throughout the southern Lower Peninsula. Limited band regions of Missouri, Kentucky and Indiana. Additional returns suggest that Michigan’s Indiana bats hibernate in limestone caves in these three states as well as in the caves of Kentucky (Davis, in Kurta 1980). In 1994, Tennessee, Arkansas and others as far north as the however, Kurta and Teramino (1994) reported one New England area harbor smaller groups. female Indiana bat hibernating with approximately 15,000 bats at the spillway of Tippy Dam, a State Distribution: Prior to an intensive survey hydroelectric facility near Wellston, Manistee County. beginning in 1978 (Kurta 1980), there were only nine To date, both adult male and female Indiana bats have known records of this species (all recorded from May to been observed (Kurta et al. 1997), and banded October) scattered in Michigan’s southernmost three individuals have been recaptured two or more years tiers of counties. In 1978 and 1979, 16 additional after their original capture, indicating fidelity to the dam individuals were captured in mist nets in four counties: (Kurta 1998). Eaton, Hillsdale, Livingston, and St. Joseph. Currently,

Michigan Natural Features Inventory P.O. Box 30444 - Lansing, MI 48909-7944 Phone: 517-373-1552 Indiana bat, Page 2

Recognition: The Indiana bat is one of Michigan’s than 30 m), and a minimum of 3 nights of netting smaller bats. Total body length ranges from 73 - 100 (USFWS 1996). Nets should be checked approximately mm (2.9 - 3.9 in); tail length ranges from 27 - 44 mm every 20 minutes from dusk to dawn, although the (1.1 - 1.7 in); wingspan is 240 - 280 mm (9 - 11 in); and period from sunset to four hours after sunset weight ranges from 6 - 11 g (0.2 - 0.4 oz) (Kurta 1995). encompasses the major activity period of bats (Kunz Fur is grayish brown with short, rounded, dark 1973). Bats that become tangled in the net can be ears; wing membranes are dark; the bat’s carefully removed and examined to determine species, underside has a pinkish cast. An Indiana bat needs to sex, reproductive condition and weight. Detectors like be held in-hand to distinguish it from Michigan’s other Anabat, which record the ultrasonic vocalizations of eight species (Kurta 1982, Baker 1983), particularly to bats, may help simplify future surveys. However, distinguish it from the two similarly sized and colored additional work needs to be done to separate and Myotis species. Indiana bats can be readily identified by identify the specific vocalizations of the various species the following detailed characteristics: the tragus (a of Myotis (Kurta 2000). Potential hibernacula (natural fleshy projection in the ear which aids in echolocation) caves and abandoned mines) can be checked for the is at least half the length of the ear, a distinct presence of Indiana bat, but this work should be done elevated ridge is present on the calcar (a structure only by an experienced biologist with specialized extending from the heel to support the back margin of equipment. the tail), and the hairs on the hind toes are less than the length of the toenail (Hall 1962, Barbour and Comments: Like any wild , a bat should not be Davis 1969). Michigan’s two other Myotis species, the handled casually or without protective equipment. Bats northern long-eared bat and the , lack the that are handled will bite in self-defense, and sick calcar. In addition, the ears of the northern long-eared individuals are more likely to be caught. Following bat, when laid forward, extend beyond the tip of the established protocol, there is very little danger of disease nose (those of the Indiana bat do not), and the little transmittal to humans. brown bat has hairs that are distinctly longer than the tips of the hind claws. Habitat: The Indiana bat forms colonies and forages in riparian and mature floodplain habitats (Humphrey et al. Best Survey Time: Mist netting perpendicular to 1977, Clark et al. 1987). Foraging typically occurs over travel corridors, such as streams, rivers and logging slow-moving, wooded streams and rivers as well as in trails, is the best method for capturing the Indiana bat. the canopy of mature trees. Movements also may However, Humphrey et al. (1977) found that this extend into the outer edge of the floodplain and to species was difficult to capture in mist nets, even when nearby solitary trees. Upland areas isolated from it was known to be foraging over the netting area. Mist floodplains and non-wooded streams are generally netting from 15 May - 15 August is generally effective. avoided (Humphrey et al. 1977). Nursery roost sites Indiana bats begin leaving the roost to feed about 25 consisting of females and young are usually located minutes after sundown (Kurta 1995). In general, mist under loose bark or in hollows and crevices of trees. netting utilizes a pair of poles positioned under The summer habitat of the male Indiana bat is poorly overhanging tree branches on opposite sides of the understood. Summering males in Missouri were found travel corridor. Two to four very fine mesh nets are mainly to be foraging among trees rather than over stacked vertically and suspended above the corridor water. During winter, Indiana bats hibernate in caves between pulley ropes attached to the poles. Using this and mines. Indiana bats typically avoid houses or other system, it is possible to raise the top of the uppermost artificial structures. net to the canopy and create a wall of netting that blocks most or all of the flyway. A typical set is 7 m Biology: Most Indiana bats migrate into the Great high (3 nets stacked on top of one another) and up to 20 Lakes basin beginning in late April. Once here females m long. Sampling of one net site per km of flyway and 2 form nursery or maternity colonies, which may be as net sites per square km of habitat constitutes a minimum large as 100 individuals. The loose bark of dead trees is level of effort. Netting at each site should consist of 4 used for roosting, especially green ash, red oak, net nights (unless bats are caught sooner), a minimum shagbark hickory, American elm, and cottonwood. Most of 2 net locations at each sites (preferably no closer roost trees are in heavily canopied forest, but some are

Michigan Natural Features Inventory P.O. Box 30444 - Lansing, MI 48909-7944 Phone: 517-373-1552 Indiana bat, Page 3 in pastures or open wetlands. Population size at any one have air temperatures of 4 -8oC (39 - 46oF) and a roost can fluctuate dramatically. For example the relative humidity between 75 - 95% throughout winter population at one green ash tree in Michigan varied from (Clawson 1987). Few caves provide the microclimatic 4 to 45 as the bats shifted back and forth, conditions required by this species. Hibernating Indiana among eight different trees, located within 160 m (525 bats cluster very tightly together, more so than any other ft) of each other (Kurta et al.1996). Data from banded North American species, and they carpet the ceiling of individuals indicate females return to the same general their hibernacula in densities of 3,200 bats/m2 (300 bats/ area each spring and occasionally occupy the same tree ft2). that was used the previous summer. During summer, males roost singly or in small groups. Kurta’s extensive work with the Indiana bat in Michigan has shown that the species is more adaptable than once Bats are most active during crepuscular and nighttime thought and that the species likely behaves differently in hours. Indiana bats prefer foraging in dense floodplain the northern portion of its range. While the bat generally forest where they fly just above or below the canopy. A was believed to prefer roosts underneath exfoliating summer colony’s foraging area usually encompasses a bark, crevice roosts appear to be favored in Michigan. stretch of stream over a half-mile (0.8 km) in length Data from Illinois (Gardner et al. 1991) suggest that (Humphrey et al. 1977, LaVal and LaVal 1980). unshaded trees are too warm for the bats, yet individuals Echolocation is used to avoid obstacles and locate prey. in Michigan show an apparent preference for roost trees An Indiana bat eats flies, and caddisflies that it receiving large amounts of sunlight. Calahan et al. captures in its mouth or plucks out of the air with a wing (1997) recently claimed that maintenance of old-growth or tail membrane. LaVal and LaVal (1980) found that oaks and hickories is essential to management of moths comprised 60 - 95% of their diet in Missouri. Bats Indiana bats, yet Kurta (1997) reports much lower use are extremely beneficial in the control of insects, and of these two species, and a corresponding higher use of individual bats can eat nearly 3,000 insects in one night. elms, ashes and maples. Since vegetative and climatic conditions vary across the species range, Michigan Like all Michigan bats, ovulation and fertilization by managers must be cautious in applying information from stored sperm occurs in April, when females come out of other states. Michigan specific data will be needed to hibernation. Gestation is probably 60 days, similar to that develop effective management guidelines. of the little brown bat (Kurta 1995). A female wanders over a home range of 52 ha (128 acres) when pregnant Conservation/Management: and expands this to 94 ha (232 acres) after the birth of a The Indiana bat population has declined more than 50% single pup in June or early July. Warm temperatures in since 1960. It was first added to the federal endangered early summer are crucial to the growth of young bats species list in 1967. Unfortunately, numbers have (Humphrey et al. 1977). Under normal conditions, the continued to fall since the species was listed, even young are able to fly within one month after birth. though the major hibernacula are now protected with Courtship and mating begin in late summer near a specially designed cave gates. Western populations are hibernaculum, and sometimes last into the winter. more unstable and declining faster than eastern ones. It Starting in late August, Indiana bats begin migrating to is likely that other mortality factors experienced during southern swarming sites, but stragglers remain in migration and/or on the summer breeding grounds are northern areas until at least late September. Predation is contributing to the decline. To halt the decline, the rare. Survival is relatively high for Indiana bats in federal recovery team is emphasizing protection of undisturbed environments, with average lifespans of ten hibernacula and basic research on the Indiana bat in years in females and 6 years in males (Humphrey and summer. Cope 1977). A primary limiting factor in the summer range is The Indiana bat spends its six-month hibernation in mine selective deforestation of riparian habitats, which usually tunnels and natural caverns, most of which are far south occurs from the cutting of large, dead trees for of the Great Lakes drainage; major hibernacula, each firewood. Cleaning of designated drains, stream containing 100,000 or more Indiana bats, exist in Indiana, channelization, bank modification including lawns Kentucky and Missouri. These underground retreats extended to the waters edge and agricultural

Michigan Natural Features Inventory P.O. Box 30444 - Lansing, MI 48909-7944 Phone: 517-373-1552 Indiana bat, Page 4 development along stream banks, also contribute to Calahan, E.V., III., R.D. Drobney and R. Clawson. habitat destruction. Tree removal or land clearing for 1997. Selection of summer roosting sites by Indiana agriculture, urban development, surface mining, or utility bats (Myotis sodalis) in Missouri. J. Mammal. and transportation rights-of way could directly affect 78:818-825. local Indiana bat populations. The removal of standing, dead trees that are potential Indiana bat roosts, Clark, B.K., J.B. Bowles and B.S. Clark. 1987. especially during the summer months, could be harmful. Summer status of the endangered Indiana bat in Iowa. Pesticides have been implicated in the declines of a Am. Midl. Nat. 118:32-39. number of insectivorous bats in North America. Their effects on Indiana bats have yet to be studied, and such Clawson, R.L. 1987. Indiana bats: down for the count. work is urgently needed. Bats hibernating in mines are Tech. Bull. 12(9):9-11. vulnerable to ceiling collapse. Gardner,J.E., J.D. Garner and J.E. Hofmann. 1991. In Michigan, the bat’s riparian habitat can be maintained Summer roost selection and roosting behavior of by protecting mature, wooded areas, leaving large, dead Myotis sodalis (Indiana bat) in Illinois. Illinois trees standing, and maintaining wide vegetation buffer Natural History Survey, Unpubl. rept. Champaign, IL. strips. Known hibernacula and nursery colonies should be protected. In some cases, acquisition of suitable Hall, J.S. 1962. A life history and taxonomic study of habitat may be justified. the Indiana bat, Myotis sodalis. Reading Publ. Mus. Art Gallery Sci. Publ. No. 12. Indiana bat populations are not stable. If the current rate of decrease continues, it is likely that the species could Humphrey, S.R. and J.B. Cope. 1977. Survival rates of be extinct within 35 years (McKenzie 1995). It may well the endangered Indiana bat, Myotis sodalis. J. be that peripheral populations of the Indiana bat, like the Mammal. 58:32-36. Michigan one, represent the species best hope for long- term survival. Humphrey, S.R., A.R. Richter and J.B. Cope. 1977. Summer habitat and ecology of the endangered Research Needs: Intensive surveys to locate nursery Indiana bat. J. Mammal. 58:334-46. colonies in Michigan, following Kurta’s successful methods (Kurta 1980), are crucial. Better information is Kunz, T.H. 1973. Resource utilization: spatial and needed on the species summer habitat requirements, the temporal components of bat activity in central Iowa. effects of riparian habitat destruction, the effects of J. Mammal. 54:14-32. water pollution and siltation, and the effects of chemical contamination from widespread use of pesticides. Kurta, A. 1980. Status of the Indiana bat, Myotis Additional work with bat detector systems is needed to sodalis, in Michigan. Mich. Acad. Sci. 13:31-36. separate Indiana bat from other Myotis spp. in a variety of habitat types. Kurta, A. 1982. A review of Michigan bats: seasonal and geographic distribution. Mich. Acad. Sci. 15:295- Related Abstracts: southern floodplain forest, mesic 312. northern forest, oak barrens, red-shouldered hawk, cerulean warbler, copperbelly watersnake, clubshell Kurta, A. 1995. of the Great Lakes Region. The Univ. of Mich. Press, Ann Arbor, MI. 376 pp. Selected references: Kurta, A. 1997. Ecology and behavior of the Indiana Baker, R.B. 1983. Michigan mammals. Mich. State bat (Myotis sodalis) along the Raisin River. Mich. Univ. Press, E. Lansing, MI. 642 pp. Dept. Nat. Resour., Unpubl. rpt. Lansing, MI. 30 pp.

Barbour, R.W. and W.H. Davis. 1969. Bats of Kurta, A. 1998. Bats and Tippy Dam: postrehabilitation America. Univ. Kentucky Press, Lexington, KY. monitoring. Consumers Energy, Unpubl. rept. Cadillac, MI. 26 pp.

Michigan Natural Features Inventory P.O. Box 30444 - Lansing, MI 48909-7944 Phone: 517-373-1552 Indiana bat, Page 5

Kurta A. 2000. Ultrasonic identification of flying bats: a potential management tool. Mich. Dept. Nat. Resour., Unpubl. rept. Lansing, MI. 29 pp.

Kurta, A. and J.A. Teramino. 1994. A novel hibernaculum and noteworthy records of the Indiana bat and eastern pipistrelle (Chiroptera: Vespertilionidae). Amer. Midl. Nat. 132:410-413.

Kurta, A., T. Hubbard and M.E. Stewart. 1989. Bat species diversity in central Michigan. Jack-Pine Warbler 67:80-87.

Kurta, A., K.J. Williams and R. Mies. 1996. Ecological, behavioural, and thermal observations of a peripheral population of Indiana bats. Pages 102-117 in Bats and forests (R.M.R Barclay and R.M. Brigham, eds.). Research Branch, Ministry of Forests, Province of British Columbia, Victoria, B.C. 292 pp.

Kurta, A., J. Caryl and T. Lipps. 1997. Bats and Tippy Dam: species composition, seasonal use, and environmental parameters. Michigan Academician 24:473-490.

LaVal, R.K. and M.L. LaVal. 1980. Ecological studies and management of Missouri bats with emphasis on cave-dwelling species. Terrestrial Ser., Missouri Dept. Conserv. No. 8.

McKenzie, P. 1995. Draft minutes of September 19, 1995, Indiana Bat Recovery Team meeting. 6 pp.

Michigan Natural Features Inventory. 2001. Biological and conservation data system. Lansing. MI.

U. S. Fish and Wildlife Service. 1996. Technical draft Indiana bat (Myotis sodalis) recovery plan. Fort Snelling, MN.

Abstract citation: Rabe, M.L. 2001. Special abstract for Myotis sodalis (Indiana bat). Michigan Natural Features Inventory. Lansing, MI. 5 pp. Copyright 2004 Michigan State University Board of Trustees. Michigan State University Extension is an affirmative-action, equal-opportunity organization.

Funding for abstract provided by Michigan Department of Natural Resources-Forest Management Division and Wildlife Division.

Michigan Natural Features Inventory P.O. Box 30444 - Lansing, MI 48909-7944 Phone: 517-373-1552