Roadless Areas
Home/Species/ Eastern Small-footed Myotis

Myotis leibii

(Audubon and Bachman, 1842)

Eastern Small-footed Myotis

G4Apparently Secure Found in 8 roadless areas NatureServe Explorer →
G4Apparently SecureGlobal Rank
EndangeredIUCN
Medium - lowThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.106402
Element CodeAMACC01130
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNEndangered
Endemicoccurs (regularly, as a native taxon) in multiple nations
KingdomAnimalia
PhylumCraniata
ClassMammalia
OrderChiroptera
FamilyVespertilionidae
GenusMyotis
Synonyms
Myotis subulatusMyotis subulatus leibii(Audubon and Bachman, 1842)
Other Common Names
Chauve-souris pygmée de l'Est (FR) Eastern Small-footed Bat (EN) Un Murciélago (ES) Vespertilion pygmée de l'Est (FR)
Concept Reference
Wilson, D. E., and D. M. Reeder (editors). 2005. Mammal species of the world: a taxonomic and geographic reference. Third edition. The Johns Hopkins University Press, Baltimore. Two volumes. 2,142 pp. [As modified by ASM the Mammal Diversity Database (MDD) at https://www.mammaldiversity.org/index.html]
Taxonomic Comments
Formerly, M. ciliolabrum was included as a subspecies of M. leibii (or M. subulatus). Analysis by Ammerman et al. (2016) of nuclear amplified fragment length polymorphism (AFLP) markers recovered distinct genetic lineages or clusters that corresponded to the recognized species defined by morphology, M. californicus, M. ciliolabrum, and M. leibii.
Conservation Status
Rank MethodLegacy Rank calculation - Excel v3.1x
Review Date2016-04-04
Change Date2015-03-11
Edition Date2015-03-31
Edition AuthorsHammerson, G.
Threat ImpactMedium - low
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
Widespread in southeastern Canada and eastern United States; numerous localities but very spotty distribution; rarely found in large numbers; historically the total numbers counted have been very low in comparison to the total number of caves and mines surveyed; recent data indicate relatively stable populations and no apparent significant impact of white-nose syndrome.
Range Extent Comments
The range extends from New England, southeastern Ontario, and southwestern Quebec south and west to southeastern Oklahoma, Arkansas, northern Alabama, northern Georgia, and northwestern South Carolina (Menzel et al. 2003). A map is included in Best and Jennings (1997). Within this range, the distribution is very spotty, and the bulk of the occurrences and largest populations are in New York, Pennsylvania, West Virginia, and western Virginia (Amelon and Burhans 2006). The majority of known hibernacula occur in Pennsylvania (n=55), New York (n=53), West Virginia (n=50), Virginia (n=33), Kentucky (n=26), and North Carolina (n=25) (USFWS 2013). This species is apparently extirpated in Connecticut and Ohio (where known from only one specimen). Elevational range extends to at least 700-800 meters in several states, at least 1,125 meters in Kentucky (see Best and Jennings 1997), and to at least 1,447 meters in North Carolina (O'Keefe and LaVoie 2011).
Occurrences Comments
The number of distinct occurrences has not been determined using standardized criteria, but the species is represented by a large number of collection/observation sites and locations (as defined by IUCN). The species has been found in 289 hibernacula (USFWS 2013; time frame not reported). In recent years (but prior to the prevalence of white-nose syndrome), it was counted at approximately 125 hibernacula (Amelon and Burhans 2006). Recent surveys have greatly increased the number of localities above those known historically; the number of hibernacula may be significantly larger than currently known. Intensive cave and mine surveys have been undertaken in most states where the species occurs, but some sites probably remain unsearched in most states, and some likely roost sites are inaccessible to surveyors. Also, this relatively secretive bat may go undetected in sites where it is present.
Threat Impact Comments
The most serious threat to bats in eastern North America is white-nose syndrome (WNS), an often (but not always) lethal condition caused by a fungal pathogen that attacks hibernating bats. WNS was first noticed in 2006 in New York. Since its initial discovery, WNS has spread rapidly and now has been documented throughout the range of Myotis leibii (http://www.fws.gov/whitenosesyndrome/maps/WNSMap_060111_300dpi_DS.jpg). WNS affects Myotis leibii and several other bat species and has resulted in several million bat deaths in eastern North America. As of early 2015, WNS was still spreading but was confined primarily to areas east of the Mississippi River (plus several locations in Arkansas and Missouri, with suspected instances in Iowa and Minnesota). USFWS (2013) reviewed available information on population trends and WNS effects on M. leibii and concluded that WNS does not appear to have caused a significant population decline in hibernating M. leibii.

USFWS (2013) determined that although several activities, such as construction of physical barriers at cave accesses, mining, flooding, vandalism, development, and timber harvest may modify or destroy M. leibii habitat, these activities do not have significant, population-level effects on the species. Climate change, contaminants, wind energy development, and prescribed burning are not believed to be causing population declines in M. leibii (USFWS 2013). Some of these potential or localized threats are discussed further in the following paragraphs.

Closures of mines used for hibernation are a potential threat, but there is no evidence that mine closures are currently affecting Myotis leibii populations (USFWS 2011). Some mines may be threatened by collapse. Ceiling collapse may kill bats outright or, more significantly, alter cave microhabitat enough to make it unsuitable. A few cave occurrences are threatened or have been reduced in quality due to commercialization for tourism.

Threats to summer sites are unknown but likely to be moderate due to alteration of riparian habitats. Conversion of forested habitats to agricultural and residential uses has decreased the amount of preferred habitat in some areas, but the bats do make use of bridges and various other non-natural roost sites. Reliance on loose shale, talus, or karst formations often found in oil-, gas-, and mineral-rich lands makes M. leibii vulnerable to habitat loss associated with natural resource exploitation (Center for Biological Diversity 2010, USFWS 2011).

Development of wind power may pose a threat in some areas. Myotis leibii typically roosts in talus areas that occur on ridgetops. In the Appalachian Mountains, such roosting areas coincide with past, present, and anticipated future wind power development. Thus this bat may be exposed to both habitat loss due to project construction and direct mortality from turbine operation (Center for Biological Diversity 2010, USFWS 2011). However, significant mortality from turbines has not yet been documented (Arnett and Baerwald 2013).

Improper gating of caves to protect bats may result in site abandonment. For example, construction associated with commercializing the Fourth Chute Cave in Ontario, Canada, eliminated the circulation of cold air in one of the unvisited passages where a relatively large number of M. leibii hibernated; the bats were completely displaced as a result of the warmer microclimate produced (Mohr 1972). In other locations (e.g., Aitkin Cave, Pennsylvania), correctly installed gates led to increases in M. leibii populations (Butchkoski, pers. comm., 2012, cited by USFWS 2013).

Human disturbance is a potential threat at approximately half of the known hibernacula in Kentucky, Maryland, North Carolina, Vermont, and West Virginia, but there is no evidence that disturbance has led to population declines (USFWS 2013). With its small numbers and spotty distribution, isolated colonies of M. leibii are particularly vulnerable to extirpation by chance events, especially when concentrated during winter months. On the other hand, in contrast to certain other bats that assemble in vast numbers in relatively few sites, the population of M. leibii as a whole is not vulnerable to localized events.

THREATS TO BATS IN GENERAL: Other than white-nose syndrome, perhaps the most serious threat to cave-dwelling bats is human disturbance during hibernation. Very low levels of noise, light, and heat from lanterns are sufficient to awaken hibernating bats, which then expend energy moving about and deplete critical reserves of body fat. When disturbance is repeated, bats (especially juveniles) are likely to perish. "By the end of the winter energy reserves may be insufficient to meet the demands of the first feeding forays, when emerging insects may be scattered and scarce, or the bats may be too weak to make long flights to their summer territories" (Mohr 1976). Such disturbance is equally lethal, whether caused by vandals, well-meaning spelunkers, or bat researchers.

Intentional killing of bats in caves by clubbing, stoning, burning, bombing, etc,. has been a significant cause of mortality. Documented examples are numerous (Greenhall 1973, Harvey 1976, Tuttle 1979, and others). Bats are sometimes exterminated from commercial caves, or if not, leave or move to suboptimal habitats due to increased disturbance.

Poisoning by pesticides, heavy metals, and other environmental contaminants has been and may remain a significant threat (Clark 1988). Destruction of roost and foraging habitat by reservoir inundation, strip mining (especially limestone), deforestation, drainage of wetlands, development, etc., and pollution or siltation of waterways with consequent decline in insect production are additional potential adverse impacts (Tuttle 1979). Hundreds of thousands of bats have been destroyed by natural flooding of caves (Hall 1962, Brady 1979).
Ecology & Habitat

Description

This is a very small bat with tiny feet, a dark mask, and dark ears. The tragus is long and pointed, and the tail reaches the edge of the interfemoral membrane. There are no prominent chin or nose flaps. The dorsal pelage is pale yellowish brown to golden brown. The ears are black, and the face has a black "mask." The belly hair varies from pale buff to whitish. The bases of the hairs on the back are blackish; wing and tail membranes are very dark brown. The base of the interfemoral membrane and under surfaces of wing membranes are sparsely furred. The calcar has a definitive keel. Sexes are similar; females have two mammae. Size is very small, with total length 72 to 84 mm, tail 30 to 39 mm, hind foot 6 to 8 mm, forearm 30-36 mm, and wingspread 212 to 248 mm; adult mass is 3 to 8 grams (Banfield 1974, Godin 1977, Schwartz and Schwartz 1981, Merritt 1987).

Excellent photographs of small-footed bats and their skulls have been published, including Barbour and Davis (1969, 1974), Whitaker (1980), and Merritt (1987). Also see skull illustrations in van Zyll de Jong (1984).

Diagnostic Characteristics

This bat differs from other sympatric bats by a) small size, < 8.5 cm, b) small hind foot, < 8 mm, c) black face, d) long-keeled calcar, and e) absence of a dark shoulder patch. It differs from M. lucifugus by having golden-tinted, almost yellowish fur and a shorter forearm. It differs from Pipistrellus subflavus by its lighter color, especially the light pinkish forearms, and lack of a keeled sternum (Godin 1977). The skull is much flatter than that of M. lucifugus, and the braincase is narrower; a sagittal crest may be present (Banfield 1974, Godin 1977, Schwartz and Schwartz 1981, Merritt 1987). See Whitaker and Hamilton (1998) for a key to the vespertilionid bats of eastern North America.

Habitat

Habitat is mostly hilly or mountainous, generally in or near deciduous or coniferous forest. Like many other bat species, this one often forages over ponds and streams; foraging habitat also includes riparian forests, upland forests, clearings, stripmines, and ridgetops (see USFWS 2013). Foraging flights tend to be slow and often within a few meters of the ground or water surface (Davis et al. 1965; Brack et al., unpublished, cited by USFWS 2013).

Warm-season roosts may be primarily in cracks or crevices of rocky outcrops or talus slopes but also have been found in buildings (including the slate roof of a house), bridges (e.g., in expansion joints, guardrail crevices), towers, hollow trees, spaces beneath the loose bark of trees, road cuts, rocky dams, caves, and mines (Tuttle 1964, Barbour and Davis 1969, Best and Jennings 1997, Roble 2004, Johnson and Gates 2008, Johnson et al. 2011, O'Keefe and LaVoie 2011, USFWS 2013, Whitby et al. 2013). The species relies heavily on rock roosts or similar man-made structures during the summer months (Erdle and Hobson 2001, Johnson et al. 2011). Roosts often are exposed to the sun but also may be under moderate to extensive canopy cover (Johnson et al. 2011, Thomson and O'Keefe 2012). Recaptures of marked individuals in successive years indicate that the bats exhibit fidelity to their summer roosts (see USFWS 2013).

In West Virginia, M. leibii used primarily ground-level rock roosts in talus slopes and rock fields, and sometimes roosted in vertical cliff faces; males and females frequently switched roosts (Johnson et al. 2011). Ground-level roosts had low canopy cover but were located close to vegetation. Ground-level roosts generally were a few hundred meters from ephemeral water sources; roosts used by females were closer to ephemeral water sources than were those used by males.

In Tennessee, two individuals found in April were under a large flat rock at the edge of a quarry surrounded by woods and cow pastures (Tuttle 1964). In late July and early August in southern Illinois, many individuals, including post-lactating females and juveniles were found under loose rocks on exposed rock outcrops (Whitby et al. 2013). In Ontario, about 12 of these bats were found in July behind the door of a shed that was kept open (i.e., positioned against the wall) (Hitchcock 1955). These bats have been seen resting in limestone caves in West Virginia in spring and summer (Krutzsch 1966).

By far most records come from observations of bats hibernating in winter in caves and mine tunnels. Hibernation occurs in solution and fissure caves and mine tunnels (including coal, iron, copper, and talc mines). Dunn and Hall (1989) noted that 52 percent of Pennsylvania hibernacula were small caves of less than 150 meters (500 feet) in length. Situations near the entrance where the air is relatively cold and dry seem to be preferred (Barbour and Davis 1969), though sometimes deeper locations are used (Schwartz and Schwartz 1981). Roost sites often are deep in crevices, or under rocks or in crevices on the cave floor, where the bats can be very difficult to find (Davis 1955, Krutzsch 1966, Martin et al. 1966). These bats are usually found singly or occasionally in small clusters, but many may be packed in a crevice; often they hang among other species (Marin et al. 1966). Individuals exhibit a high degree of fidelity to hibernacula and can be found in the same site in multiple years (Gates et al. 1984).

Ecology

Possible predators include domestic cats, mink, raccoons, opossum, fish, frogs, snakes, and birds of prey. Most of these are known to prey occasionally on other Myotis species (Barbour and Davis 1969).

Reproduction

Breeding may occur in the fall, with the sperm stored in the uterus over winter. Active gestation lasts probably two months, with a single offspring born annually, probably in early July (Merritt 1987).

Survival rates are significantly lower for females (42%) than for males (76%) (van Zyll de Jong 1985). One individual is reported to have lived 12 years (Hitchcock 1965).

Colonies are usually small (< 15, e.g. Hitchcock 1955), though a few number in the hundreds. Small maternity colonies of 12 to 20 individuals occurring in buildings have been reported (Merritt 1987).
Terrestrial Habitats
Forest - HardwoodForest - ConiferForest - MixedBare rock/talus/screeCliff
Palustrine Habitats
RiparianAerial
Other Nations (2)
United StatesN3
ProvinceRankNative
TennesseeS2Yes
New HampshireS1Yes
MassachusettsS1Yes
IllinoisS1Yes
IndianaS2Yes
ArkansasS1Yes
District of ColumbiaSNRYes
VirginiaS2Yes
North CarolinaS2Yes
MissouriS2Yes
South CarolinaS2Yes
MarylandS1Yes
OhioSHYes
OklahomaS1Yes
VermontS1Yes
GeorgiaS2Yes
New YorkS2Yes
PennsylvaniaS2Yes
ConnecticutS1BYes
New JerseyS1Yes
MaineS1Yes
West VirginiaS2Yes
KentuckyS2Yes
CanadaN2
ProvinceRankNative
QuebecS1Yes
OntarioS2Yes
Threat Assessments
ThreatScopeSeverityTiming
1 - Residential & commercial developmentNegligible (<1%)—High (continuing)
1.1 - Housing & urban areas——High (continuing)
2 - Agriculture & aquacultureNegligible (<1%)Moderate - slightHigh (continuing)
2.1 - Annual & perennial non-timber crops——High (continuing)
3 - Energy production & miningSmall (1-10%)Slight or 1-10% pop. declineHigh (continuing)
3.2 - Mining & quarrying——High (continuing)
4 - Transportation & service corridorsNegligible (<1%)Moderate - slightHigh (continuing)
5 - Biological resource useNegligible (<1%)Moderate - slightHigh (continuing)
5.3 - Logging & wood harvesting——High (continuing)
6 - Human intrusions & disturbanceRestricted - smallModerate - slightHigh (continuing)
6.1 - Recreational activities——High (continuing)
7 - Natural system modificationsNegligible (<1%)Moderate - slightHigh (continuing)
7.1 - Fire & fire suppression——High (continuing)
7.2 - Dams & water management/use——High (continuing)
8 - Invasive & other problematic species, genes & diseasesRestricted - smallSerious or 31-70% pop. declineHigh (continuing)
8.1 - Invasive non-native/alien species/diseases——High (continuing)
9 - PollutionUnknownUnknownHigh (continuing)
10 - Geological eventsNegligible (<1%)——
11 - Climate change & severe weatherPervasive (71-100%)UnknownHigh (continuing)

—

Roadless Areas (8)
North Carolina (3)
AreaForestAcres
Chunky Gal (addition)Nantahala National Forest3,336
Lost CovePisgah National Forest5,944
Wesser BaldNantahala National Forest4,061
Virginia (5)
AreaForestAcres
Adams PeakGeorge Washington National Forest7,135
James River AdditionJefferson National Forest1,140
Kelley MountainGeorge Washington National Forest7,590
Saint Marys AdditionGeorge Washington National Forest1,454
The PriestGeorge Washington National Forest5,737
References (129)
  1. Amelon, S., and D. Burhans. 2006a. Conservation assessment: <i>Myotis leibii</i> (eastern small-footed myotis) in the eastern United States. Pages 57-68 in Thompson, F. R., III, editor. Conservation assessments for five forest bat species in the eastern United States. U.S. Department of Agriculture, Forest Service, North Central Research Station, General Technical Report NC-260. St. Paul, Minnesota. 82 pp.
  2. American Society of Mammalogists (ASM). 2025. Mammal Diversity Database (Version 1.13) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.10595931. Online. Available: https://www.mammaldiversity.org/
  3. Ammerman, L. K., D. N. Lee, and R. S. Pfau. 2016. Patterns of genetic divergence among <i>Myotis californicus</i>, <i>M. ciliolabrum</i>, and <i>M. leibii</i> based on amplified fragment length polymorphism. Acta Chiropterologica 18(2):336-346.
  4. Arnett, E. B., and E. F. Baerwald. 2013. Impacts of wind energy development on bats: implications for conservation. Pages 435-456 in R. A. Adams and S. C. Pedersen (editors). Bat evolution, ecology, and conservation. Springer Science+Business Media, New York.
  5. Baker, R. H. 1983. Michigan mammals. Michigan State University Press. 642 pp.
  6. Baker, R. J., L. C. Bradley, R. D. Bradley, J. W. Dragoo, M. D. Engstrom, R. S. Hoffman, C. A. Jones, F. Reid, D. W. Rice, and C. Jones. 2003a. Revised checklist of North American mammals north of Mexico, 2003. Museum of Texas Tech University Occasional Papers 229:1-23.
  7. Banfield, A. W. F. 1974. The mammals of Canada. University of Toronto Press, Toronto, Canada. 438 pp.
  8. Barbour, R. W., and W. H. Davis. 1969. Bats of America. The University of Kentucky Press, Lexington, Kentucky. 286 pp.
  9. Barbour, R. W., and W. H. Davis. 1974. Mammals of Kentucky. University Press of Kentucky, Lexington, Kentucky.
  10. Best, T. L., and J. B. Jennings. 1997. <i>Myotis leibii</i>. Mammalian Species (547):1-6.
  11. Boynton, Allen. North Carolina.
  12. Bradley, R.D., L.K. Ammerman, R.J. Baker, L.C. Bradley, J.A. Cook. R.C. Dowler, C. Jones, D.J. Schmidly, F.B. Stangl Jr., R.A. Van den Bussche and B. Würsig. 2014. Revised checklist of North American mammals north of Mexico, 2014. Museum of Texas Tech University Occasional Papers 327:1-28. Available at: http://www.nsrl.ttu.edu/publications/opapers/ops/OP327.pdf
  13. Brady, J. T. 1979. The status of the Indiana bat (<i>Myotis sodalis</i>). Pages 127-32 in R. C. Wilson, and J. J. Lewis. National Cave management symposium proceedings.
  14. Buchler, E. R. 1976. A chemiluminescent tag for tracking bats and other small nocturnal animals. Journal of Mammalogy 57:173-6.
  15. Byre, V. J. 1990. A group of young peregrine falcons prey on migrating bats. Wilson Bull. 102(4):728-30.
  16. Caire, W., J. D. Tyler, B. P. Glass, and M. A. Mares. 1989. Mammals of Oklahoma. University of Oklahoma Press, Norman. Oklahoma. 567 pp.
  17. Center for Biological Diversity. 2010. Petition to list the eastern small-footed bat Myotis leibii and northern long-eared bat Myotis septentrionalis as threatened or endangered under the Endangered Species Act. Center for Biological Diversity, P.O. Box 188, Richmond, VT.
  18. Clark, D. R. 1988. Environmental contaminants and the management of bat populations in the United States. Pages 409-13 in Management of amphibians, reptiles, and small mammals in North America: proceedings of the symposium. U.S. Forest Service Gen. Tech. Rep. RM-166.
  19. Clark, Mary Kay. Curator of Mammals. North Carolina State Museum of Natural Sciences. Raleigh, North Carolina.
  20. Clark, M. K. (ed.). 1987. Endangered, threatened, and rare fauna of North Carolina, part I. A re-evaluation of the mammals. Occas. Pap. North Carolina Biol.
  21. Clawson, R. L., R. K. LaVal, M. L. LaVal, and W. Claire. 1980. Clustering behavior of hibernating <i>Myotis sodalis</i> in Missouri, USA. Journal of Mammalogy 61:245-53.
  22. Cockrum, E. L. 1952. Mammals of Kansas. University of Kansas Publication, Mus. Nat. Hist. 7:1-303.
  23. Constantine, D. G. 1979. An updated list of rabies-infected bats in North America. J. Wildlife Diseases 15:347-9.
  24. Dalton, V.M. 1987. Distribution, abundance, and status of bats hibernating in caves in Virginia. Virginia Journal of Science 38(4): 369-379.
  25. Davis, W.H. 1955. <i>Myotis subulatus leibii </i>found in unusual situations. Journal of Mammalogy 36(1): 130.
  26. DeGraaf, R. M., and D. D. Rudis. 1986. New England Wildlife: Habitat, Natural History and Distribution. Northeast Forest Experiment Station, U.S. Forest Service, General Technical Report NE-108, Amherst, Massachusetts. 491 pp.
  27. Doutt, J. K., C. A. Heppenstall, and J. E. Guilday. 1977. Mammals of Pennsylvania. The Penn. Game Commission. 283 pp.
  28. Dunn, J. P., and J. S. Hall. 1989. Status of cave-dwelling bats in Pennsylvania. J. Pennsylvania Acad. Sci. 63(3):166-72.
  29. Elliott, W. R. 2003. A guide to Missouri's cave life: 70 species brought to life. Missouri Department of Conservation. 37 pp.
  30. Erdle, S. Y., and C. S. Hobson. 2001. Current status and conservation strategy for the eastern small-footed myotis (<i>Myotis leibii</i>). Virginia Department of Conservation and Recreation, Division of Natural Heritage, Richmond, VA. Natural Heritage Technical Report # 00-19. 34 pp.
  31. Felbaum, F., B. Mitchell, K. McKenna, J. Hassinger, A. Shiels, J. Hart and D. Brauning. 1995. Endangered and threatened species of Pennsylvania. Wildlife Conservation Resource Fund, Harrisburg, PA, 80 pp
  32. Feldhamer, G.A., J.E. Gates and J.A. Chapman. 1984. Rare, threatened, endangered and extirpated mammals from Maryland. Pp. 395-438 in: A.W. Nordon, D.C. Forester and G.H. Fenwich (ed.). Threatened and endangered plants and animals of Maryland. Maryland Natural Heritage Program. Annapolis, MD.
  33. Fellers, G. M., and E. D. Pierson. 2002. Habitat use and foraging behavior of Townsend's Big-eared Bat (<i>Corynorhinus townsendii</i>) in coastal California. Journal of Mammalogy 83:167-177.
  34. Fenton, M.B. 1970. Population studies of <i>Myotis lucifugus</i> (Chiroptera: Vespertilionidae) in Ontario. Life Sciences Contributions, Royal Ontario Museum, No. 77.
  35. Fenton, M. B. 1972. Distribution and over-wintering of <i>Myotis leibii</i> and <i>Eptesicus fuscus</i> (Chiroptera: Vespertilionidae) in Ontario. Royal Ontario Museum,, Life Sciences Occas. Pap. (21):1-8.
  36. Fenton, M. B., C. G. van Zyll de Jong, G. P. Bell, D. B. Campbell, and L. Laplante. 1980. Distriubution, parturition dates and feeding of bats in south-central British Columbia. Canadian Field Naturalist 94(4):416-20.
  37. Findley, J. S. 1972. Phenetic relationships among bats of the genus <i>Myotis</i>. Syst. Zool. 21(1):31-52.
  38. Garner, J. D., and J. E. Gardner. 1992. Determination of summer distribution and habitat utilization of the Indiana bat (<i>Myotis sodalis</i>) in Illinois. Illinois Department of Conservation. Final Report, Project E-3. Springfield, IL, 23 pp.
  39. Gates, J. E., G. A. Feldhamer, L. A. Griffith, and R. L. Raesly. 1984. Status of cave-dwelling bats in Maryland: importance of marginal habitats. Wildlife Society Bulletin 12:162-169.
  40. Glass, B. P., and C. M. Ward. 1959. Bats of the genus <i>Myotis</i> from Oklahoma. Journal of Mammalogy 40:194-201.
  41. Glass, B. P., and R. J. Baker. 1968. The status of the name <i>Myotis subulatus </i>Say. Proc. Biol. Soc. Washington 81:257-60.
  42. Godin, A. J. 1977. Wild mammals of New England. Johns Hopkins University Press, Baltimore. 304 pp.
  43. Greenhall, A.M. 1973. Indiana bat: a cave-dweller in trouble. National Parks and Conservation Magazine 47(8):14-17.
  44. Griffin, D. R. 1940b. Migrations of New England bats. Bulletin of the Museum of Comparative Zoology 86:217-246.
  45. Hall, E. R. 1981a. The Mammals of North America, second edition. Vols. I &amp; II. John Wiley &amp; Sons, New York, New York. 1181 pp.
  46. Hall, J. S. 1962. A life history and taxonomic study of the Indiana bat, <i>Myotis sodalis</i>. Reading Publication Museum Art Gallery, Science Publication 12. 68 pp.
  47. Hall, J. S. 1979. Status of the endangered Indiana bat, <i>Myotis sodalis</i>, in Pennsylvania. Report submitted to the Pennsylvania Game Commission. Unpublished.
  48. Hall, J. S. 1985. Small-footed bat <i>Myotis leibii </i>(Audubon and Bachman). Pages 360-2 in H. H. Genoways, and F. J. Brenner. Species of Special Concern in Pennsylvania. Carnegie Mus. Nat. Hist., Pittsburgh, Pennsylvania.
  49. Hall, J. S. and F. J. Brenner. 1968. Summer netting of bats at a cave in Pennsylvania. Journal of Mammalogy 49:779-81.
  50. Hamilton, W. J., Jr., and J. O. Whitaker, Jr. 1979. Mammals of the eastern United States. Cornell Univ. Press, Ithaca, New York. 346 pp.
  51. Handley, C. O., Jr. 1991. Mammals. Pages 539-616 in K. Terwilliger, coordinator. Virginia's endangered species: proceedings of a symposium. McDonald and Woodward Publishing Company, Blacksburg, Virginia.
  52. Harvey, M.J. 1975. Endangered Chiroptera of the southeastern United States. Proceedings of the Southeastern Association of Game and Fish Commissioners 29:429-433.
  53. Harvey, M. J., J. J. Cassidy, and G. G. O'Hagan. 1981. Endangered bats of Arkansas: distrubution, status, ecology and management. Memphis State University, Memphis, Tennessee.
  54. Henshaw, R. E. 1972. Niche specificity and adaptability in cave bats. Bull. Nat. Speleol. Soc. 34(2):61-70.
  55. Herd, R. M. 1987. Electrophoretic divergence of <i>Myotis leibii </i>and <i>Myotis ciliolabrum </i>(Chiroptera: Vespertilionidae). Can. J. Zool. 65:1857-1860.
  56. Hicks, A.C., C. J. Herzog, R. I. von Linden, S. R. Darling, and J.T.H Coleman. 2008. White-nose syndrome: field observations from the first two winters. White-nose Syndrome Workshop, Albany, New York, USA, June 9-11, 2008. 36 pp.
  57. Hill, J. E., and J. D. Smith. 1984. Bats: A Natural History. University of Texas Press, Austin, Texas. 221 pp.
  58. Hitchcock, H. B. 1949. Hibernation of bats in southeastern Ontario and adjacent Quebec. The Canadian Field Naturalist 63(2):47-59.
  59. Hitchcock, H. B. 1955. A summer colony of the least bat <i>Myotis subulatus leibii</i> (Audubon and Bachman). Canadian Field-Naturalist 69(2):31.
  60. Hitchcock, H. B. 1965. Twenty-three years of bat banding in Ontario and Quebec. Canadian Field Naturalist 79(1):4-14.
  61. Horst, R. 1972. Bats as primary producers in an ecosystem. Bull. Nat. Speleol. Soc. 34(2):49-54.
  62. Humphrey, S. R. 1971. Photographic estimation of population size of the Mexican free-tailed bat, <i>Tadarida brasiliensis</i>. Am. Midl. Nat. 86:220-3.
  63. Humphrey, S.R. 1978. Status, winter habitat, and management of the endangered Indiana bat, <i>Myotis sodalis</i>. Florida Scientist 41(2):65-76.
  64. Hunt, G., and R. R. Stitt. 1975. Cave gating. Natl. Speleol. Soc., Huntsville, Alabama.
  65. Johnson, J. B., and J. E. Gates. 2008. Spring migration and roost-selection of female <i>Myotis leibii</i> in Maryland. Northeastern Naturalist 15:453-460.
  66. Johnson, J. S., J. D. Kiser, K. S. Watrous, and T. S. Peterson. 2011. Day-roosts of <i>Myotis leibii </i>in the Appalachian Ridge and Valley of West Virginia. Northeastern Naturalist 18:95-106.
  67. Johnson, J. S., L. E. Dodd, J. D. Kiser, T. S. Peterson, and K. S. Watrous. 2012b. Food habits of <i>Myotis leibii</i> along a forested ridgetop in West Virginia. Northeastern Naturalist 19:665-672.
  68. Jones, J. K., Jr., R. S. Hoffman, D. W. Rice, C. Jones, R. J. Baker, and M. D. Engstrom. 1992a. Revised checklist of North American mammals north of Mexico, 1991. Occasional Papers, The Museum, Texas Tech University, 146:1-23.
  69. Kirkland, Gordon L. Vertebrate Museum, Shippensburg University, Shippensburg, Pennsylvania
  70. Kiser, J. D. and C. L. Elliott. 1996. Foraging habitat, food habits, and roost tree characteristics of the Indiana bat (<i>Myotis sodalis</i>) during autumn in Johnson County, Kentucky. Final report, Kentucky Department of Fish and Wildlife Resources, Frankfort, Kentucky. 65pp.
  71. Krutzsch, P. H. 1966. Remarks on silver-haired and Leib's bats in eastern United States. Journal of Mammalogy 47(1):121.
  72. Langwig, K., A. Hicks, R. von Linden, C. Herzog, S. Darling, T. French,and J. Armstrong. 2009. White nose syndrome related declines of hibernating bat species in the Northeast. Presentation at 2009 North American Society for Bat Research Symposium, Portland, Oregon.
  73. LaVal, R. K., and M. L. LaVal. 1980. Ecological studies and management of Missouri bats, with emphasis on cave dwelling species. Terrestrial Series 8, Missouri Department of Conservation.
  74. Leffler, John. Life Science Division, Ferrum College, Ferrum, Virginia
  75. Lera, T. M., and S. Fortune. 1979. Bat management in the United States. Bull. Natl. Speleol. Soc. 41:3-9.
  76. Linzey, D. W. 1998. The mammals of Virginia. McDonald and Woodward, Blacksburg, VA. 459 pp.
  77. Linzey, D.W. 2016. Mammals of Great Smoky Mountains National Park: 2016 revision. Southeastern Naturalist 15(Monograph 8):1–93.
  78. Martin, R. L., J. T. Pawluck, and T. B. Clancy. 1966. Observations on hibernation of <i>Myotis subulatus</i>. Journal of Mammalogy 47(2):348-9.
  79. McDaniel, V. Rick. Department of Biological Sciences, Arkansas State University, State University, Arkansas
  80. Menzel, J. M., M. A. Menzel, W. M. Ford, J. W. Edwards, S. R. Sheffield, J. C. Kilgo, and M. S. Bunch. 2003. The distribution of the bats of South Carolina. Southeastern Naturalist 2:121-152.
  81. Menzel, M. A., R. Odom, S. Owen, W. M. Ford, B. R. Chapman, K. V. Miller, J. Edwards, and P. Wood. 1999b. Investigation of foraging habitat use by bats with a focus on Northern Long-eared Myotis (<i>Myotis septentrionalis</i>): a comparison of methods. IN M. K. Clark, editor. Abstracts from the 1999 Colloquium on the conservation of mammals in the Southeastern United States. Available at: http://www.batworkinggroups.org/sbdnnews.htm. Accessed 2001-06-12.
  82. Merritt, J. F. 1987. Guide to the mammals of Pennsylvania. University of Pittsburgh, Pittsburgh, PA.
  83. Miller, G.S., JR. and G.M. Allen. 1928. The American Bats of the genera <i>Myotis</i> and <i>Pizonyx</i>. Bull. U.S. Nat. Mus. 144:1-218.
  84. Mohr, C. E. 1932. <i>Myotis subulatus leibii </i>and <i>Myotis sodalis</i> in Pennsylvania. Journal of Mammalogy 13:160-1.
  85. Mohr, C. E. 1933. Pennsylvania bats of the genus <i>Myotis</i>. Proc. Pennsylvania Acad. Sci. 7:38-43.
  86. Mohr, C. E. 1936. Notes on the least bat, <i>Myotis subulatus leibii</i>. Proc. Pennsylvania Acad. Sci. 10:62-5.
  87. Mohr, C. E. 1942. Results of ten years' bat marking in Pennsylvania Acad. Sci. 16:32-6.
  88. Mohr, C. E. 1972. The status of threatened species of cave-dwelling bats. Bull. Nat. Speleol. Soc. 34(2):33-47.
  89. Mohr, C. E. 1976. The protection of threatened cave bats. Pages 57-62 in T. Aley and D. Rhodes (eds.). Nat. Cave Managem. Symp. Proc. Speleobooks, Albuquerque, New Mexico.
  90. Moosman, P. R., Jr., H. H. Thomas, and J. P. Veilleux. 2007. Food habits of eastern small-footed bats (Myotis leibii) in New Hampshire. American Midland Naturalist 158:354-360.
  91. Morgan, C. N., L. K. Ammerman, K. D. Demere, J. B. Doty, Y. J. Nakazawa, and M. R. Mauldin. 2019. Field identification key and guide for bats of the United States of America. Occasional Papers, Museum of Texas Tech University, Number 360. Texas Tech University Natural Science Research Laboratory. 29 pp.
  92. O'Keefe, J. M., and M. LaVoie. 2011. Maternity colony of eastern small-footed myotis (<i>Myotis leibii</i>) in a historic building. Southeastern Naturalist 10:381-383.
  93. Poulson, T. L. 1972. Bat guano ecosystems. Bull. Natl. Speleol. Soc. 34(2):55-9.
  94. Prichard, D. E. 1987. Managing a national wildife refuge for bats. Bats Winter:6-8.
  95. Roble, S. M. 2004. Notes on an autumn roost of an eastern small-footed bat (<i>Myotis leibii</i>). Banisteria 23:42-44.
  96. Rodriguez, R. M., and L. K. Ammerman. 2004. Mitochondrial DNA divergence does not reflect morphological difference between <i>Myotis californicus</i> and <i>Myotis ciliolabrum</i>. Journal of Mammalogy 85:842-851.
  97. Saugey, David A. Wildlife Biologist, Jessieville Ranger District, Jessieville, Arkansas
  98. Saugey, D. A., V. R. McDaniel, D. R. England, M. C. Rowe, L. R. Chandler-Mozisek, and B. G. Cochran. 1993. Arkansas range extensions of the eastern small-footed bat (<i>Myotis leibii</i>) and northern long-eared bat (<i>Myotis septentrionalis</i>) and additional county records for the silver-haired bat (<i>Lasionycteris noctivagans</i>), hoary bat (<i>Lasiurus cinereus</i>) southeastern bat (<i>Myotis austroriparius</i>), and Rafinesque's big-eared bat (<i>Plecotus rafinesquii</i>). Proceedings of the Arkansas Academy of Science 47:102-106.
  99. Schwartz, C. W., and E. R. Schwartz. 1981. The wild mammals of Missouri. University of Missouri Press, Columbia. 356 pp.
  100. Sealander, J. A. and G. A. Heidt. 1990. Arkansas mammals: their history, classification, and distribution. University of Arkansas Press, Fayetteville, Arkansas.
  101. Shields, W. M., and K. L. Bildstein. 1979. Ecology 60(3):468-74.
  102. Simmons, N. B. and A. L. Cirranello. 2025. Bat Species of the World: A taxonomic and geographic database. Version 1.7. Online. Available: https://batnames.org/
  103. Steffen, B. J., T.L.Y. Osborne, T. C. Carter, and G. A. Feldhamer. 2006. The first record of the eastern small-footed myotis (<i>Myotis leibii</i>) in Illinois. Transactions of the Illinois State Academy of Science 90:87-89.
  104. Stihler, Craig, WV Div. Nat. Resources, Elkins, West Virginia
  105. Trombulak, S. C., P. E. Higuera, and M. DesMeules. 2001. Population trends of wintering bats in Vermont. Northeastern Naturalist 8:51-62.
  106. Tuttle, M. D. 1964. <i>Myotis subulatus </i>in Tennessee. J. Mamm. 45:148-149.
  107. Tuttle, M. D. 1974a. An improved trap for bats. J. Mammal. 55(2):475-477.
  108. Tuttle, M. D. 1974b. Population ecology of the gray bat (<i>Myotis grisescens</i>). Ph.D. dissertation. University of Kansas.
  109. Tuttle, M. D. 1975. Population ecology of the gray bat (Myotis grisescens): factors influencing early growth and development. University of Kansas Museum of Natural History Occasional Papers (36):1-24.
  110. Tuttle, M. D. 1976a. Population ecology of the gray bat (<i>Myotis grisescens</i>): philopatry, timing, and patterns of movement, weight loss during migration, and seasonal adaptive strategies. University of Kansas Museum of Natural History Occasional Papers (54):1-38.
  111. Tuttle, M. D. 1977. Gating as a means of protecting cave dwelling bats. Pages 77-82 in T. Aley and D. Rhodes, editors. National cave management symposium proceedings.
  112. Tuttle, M. D. 1979a. Status, causes of decline, and management of endangered gray bats. Journal of Wildlife Management 43:1-17.
  113. Tuttle, M.D. and L.R. Heaney. 1974. Maternity habits of Myotis leibii in South Dakota. Southern California Acad., Sci., Bull., 73(2):80-83.
  114. Tuttle, M. D and S. J. Kern. 1981. Bats and public health. Milwaukee Publ. Mus. Contrib. Biol. Geol. No. 48.
  115. U.S. Fish and Wildlife Service (USFWS). 1999. Agency draft Indiana Bat (<i>Myotis sodalis</i>) revised recovery plan. U.S. Fish and Wildlife Service, Fort Snelling, Minnesota. 53 pp.
  116. U.S. Fish and Wildlife Service (USFWS). 29 June 2011. 90-day finding on a petition to list the eastern small-footed bat and the northern long-eared bat as threatened or endangered. Federal Register 76(125):38095-38106.
  117. U.S. Fish and Wildlife Service (USFWS). 2 October 2013. 12-month finding on a petition to list the eastern small-footed bat and the northern long-eared bat as endangered or threatened species; listing the northern long-eared bat as an endangered species. Federal Register 78(191):61046-61080.
  118. van Zyll de Jong, C. G. 1984. Taxonomic relationships of Nearctic small-footed bats of the <i>Myotis leibii </i>group (Chiroptera: Vespertilionidae). Can. J. Zool. 62:2519-2526.
  119. van Zyll de Jong, C.G. 1985. Handbook of Canadian Mammals. Vol. II, Bats. National Museum of Natural Sciences, National Museums of Canada, Ottawa, Canada. 212 pp.
  120. Whitaker, J. O., and W. J. Hamilton. 1998. Mammals of the eastern United States. Comstock Publishing, Ithaca, New York.
  121. Whitaker, J. O., Jr. 1980. The Audubon Society field guide to North American mammals. Alfred A. Knopf, New York. 745 pp.
  122. Whitby, M., S. Bergeson, T. Carter, and S. Rutan. 2013. The discovery of a reproductive population of eastern small-footed bat, Myotis leibii, in southern Illinois using a novel survey method. Amercan Midlland Naturalist 169:229-233.
  123. White, D. H., and J. T. Seginak. 1987. Cave gate designs for use in protecting endangered bats. Wildlife Society Bull. 15:445-449.
  124. Williams, D. F., and J. S. Findley. 1979. Sexual dimorphism in vespertilionid bats. Am. Midl. Nat. 102(1):113-26.
  125. Wilson, D. E., and D. M. Reeder (editors). 1993. Mammal species of the world: a taxonomic and geographic reference. Second edition. Smithsonian Institution Press, Washington, DC. xviii + 1206 pp. Available online at: http://www.nmnh.si.edu/msw/.
  126. Wilson, D. E., and D. M. Reeder (editors). 2005. Mammal species of the world: a taxonomic and geographic reference. Third edition. The Johns Hopkins University Press, Baltimore. Two volumes. 2,142 pp. [As modified by ASM the Mammal Diversity Database (MDD) at https://www.mammaldiversity.org/index.html]
  127. Wilson, D. E., and S. Ruff. 1999. The Smithsonian book of North American mammals. Smithsonian Institution Press, Washington, D.C. 750 pp.
  128. Wimsatt, W. A. 1945. Notes on breeding behavior, pregnancy, and parturition in some vespertilionid bats of the eastern United States. Jounal of Mammalogy 26(1):23-33.
  129. Wimsatt, W. A. (ed.). 1970. Biology of Bats. (3 Volumes). Academic Press, New York, New York.