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Montana Animal Field Guide

Montana Field Guides

Silver-haired Bat - Lasionycteris noctivagans

Potential Species of Concern

Global Rank: G3G4
State Rank: S4

Agency Status


External Links

General Description
A mostly black bat with back hairs having silvery-shite tips. Flight membranes are black. The tail membrane has fur on the dorsal side to the tip of the tail. Ears are bare, short, and rounded with a lighter patch at the front base of the ear.

Species Range
Montana Range

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Western Hemisphere Range


Range Comments
Southern Alaska and Canada to northeastern Mexico.

Summary of Observations Submitted for Montana
Number of Observations: 1509

(Click on the following maps and charts to see full sized version) Map Help and Descriptions
Relative Density



(Observations spanning multiple months or years are excluded from time charts)

Believed to be mostly migratory, with some individuals possibly remaining year-round. There are no confirmed winter records in Montana to-date, but acoustic monitoring indicates they are likely present here in the winter.

Occupy mature conifer and deciduous forests, riparian woodlands and aspen. Summer day roosts include tree cavities, under loose bark, also bird nests, sheds, and barns. Hibernacula include tree cavities, rock crevices, and buildings.
Ecological Systems Associated with this Species
  • Details on Creation and Suggested Uses and Limitations
    How Associations Were Made
    We associated the use and habitat quality (high, medium, or low) of each of the 82 ecological systems mapped in Montana for vertebrate animal species that regularly breed, overwinter, or migrate through the state by:
    1. Using personal observations and reviewing literature that summarize the breeding, overwintering, or migratory habitat requirements of each species (Dobkin 1992, Hart et al. 1998, Hutto and Young 1999, Maxell 2000, Foresman 2001, Adams 2003, and Werner et al. 2004);
    2. Evaluating structural characteristics and distribution of each ecological system relative to the species’ range and habitat requirements;
    3. Examining the observation records for each species in the state-wide point database associated with each ecological system;
    4. Calculating the percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system to get a measure of “observations versus availability of habitat”.
    Species that breed in Montana were only evaluated for breeding habitat use, species that only overwinter in Montana were only evaluated for overwintering habitat use, and species that only migrate through Montana were only evaluated for migratory habitat use.  In general, species were associated as using an ecological system if structural characteristics of used habitat documented in the literature were present in the ecological system or large numbers of point observations were associated with the ecological system.  However, species were not associated with an ecological system if there was no support in the literature for use of structural characteristics in an ecological system, even if point observations were associated with that system.  High, medium, and low habitat quality was assigned based on the degree to which the structural characteristics of an ecological system matched the preferred structural habitat characteristics for each species in the literature.  The percentage of observations associated with each ecological system relative to the percent of Montana covered by each ecological system was also used to guide assignments of habitat quality.  If you have any questions or comments on species associations with ecological systems, please contact Bryce Maxell at or (406) 444-3655.

    Suggested Uses and Limitations
    Species associations with ecological systems should be used to generate potential lists of species that may occupy broader landscapes for the purposes of landscape-level planning.  These potential lists of species should not be used in place of documented occurrences of species (this information can be requested at: or systematic surveys for species and evaluations of habitat at a local site level by trained biologists.  Users of this information should be aware that the land cover data used to generate species associations is based on imagery from the late 1990s and early 2000s and was only intended to be used at broader landscape scales.  Land cover mapping accuracy is particularly problematic when the systems occur as small patches or where the land cover types have been altered over the past decade.  Thus, particular caution should be used when using the associations in assessments of smaller areas (e.g., evaluations of public land survey sections).  Finally, although a species may be associated with a particular ecological system within its known geographic range, portions of that ecological system may occur outside of the species’ known geographic range.

    Literature Cited
    • Adams, R.A.  2003.  Bats of the Rocky Mountain West; natural history, ecology, and conservation.  Boulder, CO: University Press of Colorado.  289 p.
    • Dobkin, D. S.  1992.  Neotropical migrant land birds in the Northern Rockies and Great Plains. USDA Forest Service, Northern Region. Publication No. R1-93-34.  Missoula, MT.
    • Foresman, K.R.  2001.  The wild mammals of Montana.  Special Publication No. 12.  Lawrence, KS: The American Society of Mammalogists.  278 p.
    • Hart, M.M., W.A. Williams, P.C. Thornton, K.P. McLaughlin, C.M. Tobalske, B.A. Maxell, D.P. Hendricks, C.R. Peterson, and R.L. Redmond. 1998.  Montana atlas of terrestrial vertebrates.  Montana Cooperative Wildlife Research Unit, University of Montana, Missoula, MT.  1302 p.
    • Hutto, R.L. and J.S. Young.  1999.  Habitat relationships of landbirds in the Northern Region, USDA Forest Service, Rocky Mountain Research Station RMRS-GTR-32.  72 p.
    • Maxell, B.A.  2000.  Management of Montana’s amphibians: a review of factors that may present a risk to population viability and accounts on the identification, distribution, taxonomy, habitat use, natural history, and the status and conservation of individual species.  Report to U.S. Forest Service Region 1.  Missoula, MT: Wildlife Biology Program, University of Montana.  161 p.
    • Werner, J.K., B.A. Maxell, P. Hendricks, and D. Flath.  2004.  Amphibians and reptiles of Montana.  Missoula, MT: Mountain Press Publishing Company. 262 p.

Food Habits
A variety of insects are eaten, including moths, flies, mosquitoes, true bugs, caddisflies, termites, and beetles. Stomach content analysis of 6 specimens from Carter County yielded Lepidoptera, Hemiptera (Corixidae), Coleoptera, Diptera,and Trichoptera.

Emerge early; slow flying. Sexes segregated; frequently change roosts. Maternity colonies are relatively small and found at lower elevations. Females typically give birth to twins, usually in late June and July.

  • Additional ReferencesLegend:   View Online Publication
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    • Adams, R.A. 2003. Bats of the Rocky Mountain West: natural history, ecology and conservation. University Press of Colorado: Boulder, CO. 289 pp.
    • Barclay, R. M. 1986. The echolocation calls of Hoary (Lasiurus cinereus) and Silver-haired (Lasionycteris noctivagans) bats as adaptations for long- versus short-range foraging strategies and the consequences for prey selection. Canadian Journal of Zoology 64:2700-2705.
    • Barclay, R. M. R. 1984. Observations on the migration, ecology and behaviour of bats at Delta Marsh, Manitoba. Can. Field-Nat. 98(3): 331-336.
    • Betts, B. J. 1998. Effects of interindividual variation in echolocation calls on identification of big brown and silver-haired bats. Journal of Wildlife Management 62:1003-1010.
    • Campbell, L. A., J. G. Hallett, and M. A. O'Connell. 1996. Conservation of bats in managed forests: use of roosts by LASIONYCTERIS NOCTIVAGANS. Journal of Mammalogy 77:976-984.
    • Fitzgerald, T. 1989. New records of bats from northeastern Colorado. Journal of the Colorado-Wyoming Academy of Science 21:22.
    • Flath, D. L. 1984. Vertebrate species of special interest or concern. Mammals, birds, reptiles, amphibians, fishes. Spec. Publ. Montana Department of Fish, Wildlife, and Parks, Helena. 76 pp.
    • Foresman, K.R. 2001. The wild mammals of Montana. American Society of Mammologists, Special Publication Number 12. Lawrence, KS. 278 pp.
    • Hendricks, P. 2000. Preliminary bat inventory of caves and abandoned mines on BLM lands, Judith Mountains, Montana. Montana Natural Heritage Program, Helena, Montana. 21 pp.
    • Izor, R. J. 1979. Winter range of the Silver-haired Bat. J. Mamm. 60:641-643.
    • Jones, J.K., Jr., R.P. Lampe, C.A. Spenrath, and T.H. Kunz. 1973. Notes on the distribution and natural history of bats in southeastern Montana. Occasional papers (Texas Tech University Museum) 15:1-11.
    • Kunz, T. H. 1982. Lasionycteris noctivagans. American Society of Mammalogists, Lawrence, KS. Mammalian Species No. 172:1-5.
    • Mattson, T. A. 1995. Owl predation on a silver-haired bat. Prairie Naturalist 27(2):127.
    • Mattson, T. A., S. W. Buskirk, and N. L. Stanton. 1996. Roost sites of the silver-haired bat (LASIONYCTERIS NOCTIVAGANS) in the Black Hills, South Dakota. Great Basin Naturalist 56:247-253.
    • Parsons, H. J., D. A. Smith, and R. F. Whittam. 1986. Maternity colonies of silver-haired bats, LASIONYCTERIS NOCTIVAGANS, in Ontario and Saskatchewan. J. Mamm. 67:598- 600.
    • Perkins, M. J. and S. P. Cross. 1988. Differential use of some coniferous forest habitats by hoary and silver-haired bats in Oregon. The Murrelet 69:21-24.
    • Reid, F. 2006. Peterson Field Guide to Mammals of North America, 4th Edition. Houghton Mifflin Company: Boston and New York, 608 pp.
    • Schowalter, D. B., W. J. Dorward, and J. R. Gunson. 1978. Seasonal occurrence of silver-haired bats (LASIONYCTERIS NOCTIVAGANS) in Alberta and British Columbia. Canadian Field-Naturalist 92(3):288-291.
    • Western Technology and Engineering, Inc. (WESTECH)., 1994, Wildlife Monitoring Absaloka Mine Area Annual Report, 1994. Montana SMP 85005. OSMP Montana 0007D. Febr. 24, 1994.
    • Wunder, L. and A.B. Carey. 1996. Use of the forest canopy by bats. Northwest Science 70:79-85.
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Citation for data on this website:
Silver-haired Bat — Lasionycteris noctivagans.  Montana Field Guide.  Montana Natural Heritage Program and Montana Fish, Wildlife and Parks.  Retrieved on May 26, 2016, from