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BC Conservation Data Centre: Species Summary


Lasionycteris noctivagans
Silver-haired Bat

 
Scientific Name: Lasionycteris noctivagans (Le Conte, 1831)
English Name: Silver-haired Bat
 
Classification / Taxonomy
Scientific Name - Concept Reference: 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/.
Classification Level: Species
Species Group: Vertebrate Animal
Species Code: M-LANO
Kingdom Phylum Class Order Family
Animalia Craniata Mammalia Chiroptera Vespertilionidae
   
Conservation Status / Legal Designation
Global Status: G4 (Jun 2025)
Provincial Status: S4S5 (Mar 2022)
BC List: Yellow
Provincial FRPA list:   
Provincial Wildlife Act:
COSEWIC Status: Endangered (May 2023)
SARA Schedule:
General Status Canada: 4 - Secure (2005)
   
Ecology & Life History
General Description:
Global Reproduction Comments: Copulation occurs in late summer or early fall. Fertilization is delayed until spring. Gestation lasts 50-60 days. Litter of 2 (occasionally 1) young is born in June-July, sometimes later in north (Kunz 1982). Young are able to fly at about 3 weeks. Individuals of both sexes become sexually mature by late summer/early fall of their first year (Cryan et al. 2012). Lifespan appears to be relatively short (oldest individuals estimated to be 12 years old; Schowalter et al. 1978). Maternity colonies are small (Parsons et al. 1986), usually with fewer than 20 individuals but sometimes as many as 55 (in a tree in South Dakota; Mattson et al. 1996).
Global Ecology Comments: During migration and summer residency, females roost alone or in maternity colonies; males typically roost alone (Barclay et al. 1988, Mattson et al. 1996, Betts 1998).
Migration Characteristics:
(Global / Provincial)		 
    Nonmigrant:
    Local Migrant:
    Distant Migrant:
    Within Borders Migrant: 		N /
Y /
Y /
na /
Global Migration Comments: These bats generally are migratory. Over the major part of the range, they are found only during spring and fall migration. South-bound migration occurs primarily in August-September (Barclay 1984, Arnett et al. 2008). See Cryan (2003) for monthly distribution based on museum records.

At Long Point, Ontario (northern side of Lake Erie), McGuire et al. (2012) found that southward migration occurred in two waves (late August and mid-September). Most bats stayed 1-2 days, although two remained longer than 2 weeks. One third of the bats foraged while at the site, many foraging opportunistically on nights when rain precluded continued migration. Half of the bats departed across Lake Erie (minimum crossing distance about 38 km) while others departed along the shoreline. Simulations predicted a migration rate of about 250-275 km per day and suggested that all but one of the bats carried sufficient fuel stores to reach the putative wintering area in the southeastern United States (estimated distance 1,500 km) in 5-6 nights without further refuelling. Migrating bats appeared to stopover for sanctuary or short-term rest as opposed to extended rest and refuelling.

Migrants occur in waves in May and early June along southern shore of Lake Manitoba (Barclay et al. 1988).
Habitats:
(Type / Subtype / Dependence) 		Anthropogenic / Industrial / Facultative - occasional use
Anthropogenic / Urban/Suburban / Facultative - occasional use
Forest / Conifer Forest - Dry / Facultative - frequent use
Forest / Conifer Forest - Mesic (average) / Facultative - frequent use
Grassland/Shrub / Grassland / Facultative - frequent use
Lakes / Lake / Facultative - frequent use
Lakes / Pond/Open Water / Facultative - frequent use
Riparian / Riparian Forest / Facultative - occasional use
Stream/River / Stream/River / Facultative - frequent use
Global Habitat Comments: Habitat is primarily forested (frequently coniferous) areas adjacent to lakes, ponds, or streams, including areas that have been altered by humans. During migration, these bats sometimes occur in xeric areas. Summer roosts and nursery sites are in coniferous or deciduous tree foliage, cavities, or under loose bark, sometimes in buildings. In the Pacific Northwest and Black Hills (South Dakota), these bats show an affinity for forests that contain large numbers of snags (Campbell et al. 1996, Mattson et al. 1996, Betts 1998). In winter, individuals have been found in mines, caves, houses, rock crevices, under loose bark, and in hollow trees.

In Oregon, maternity roosts were in cavities high in tall, declining or newly dead trees; roost fidelity of reproductive females varied among individuals: some bats used only 1 or 2 roosts from 8 to at least 13 days; others used 5 or 6 roosts from 1 to 6 days; radio-tagged bats that were in the same colony stayed together during shifts among roosts; bats moved 35 to 1,100 meters between successive roosts (Betts 1998). In South Dakota, maternity aggregations primarily were in woodpecker-created cavities in ponderosa pines (Mattson et al. 1996).

At Long Point, Ontario, late summer/early fall migrants rats roosted in a variety of tree species and human-made structures in natural and developed (e.g., residential) areas (McGuire et al. 2012). In Manitoba, migrants roosted typically in narrow crevices in tree trunks (Barclay et al. 1988).

In the Ouachita Mountains, Arkansas, Perry et al. (2010) radio-tracked 11 bats to 31 day-roosts during winter. Ninety percent of roosts were in trees (5 species): 55 percent of all all roosts were under loose bark of the bole of live overstory Pinus echinata (shortleaf pine), three percent of roosts were in a rock outcrop, and six percent were at ground level (under a tree root or in a cavity at the base of a live pine). Bats selected pine or pine-hardwood stands greater than 50 years old and used forest stands 15-50 years of age less than their availability. Most roosts were on southern topographic aspects, and bats roosted in the rock outcrop on colder days (<5 °C).

See Vonhof and Barclay (1996) for information on characteristics of roost trees in British Columbia. See Campbell et al. (1996) for roost characteristics in Washington.
Food Habits: Invertivore: Adult, Immature
Global Food Habits Comments: Diet includes a wide diversity of small to medium-size flying insects (Kunz 1982, Reimer et al. 2010) often captured over small water bodies within forested areas. Moths make up the majority of the diet (Reimer et al. 2010). Migrating individuals engage in feeding activity (Reimer et al. 2010).
Global Phenology: Nocturnal: Adult, Immature
Global Phenology Comments: Activity occurs throughout the year in southeastern Virginia and northeastern North Carolina; winter activity occurred on evenings when air temperature was 13 C or more (Padgett and Rose 1991). At low elevations in western Washington, foraging activity occurs in winter on rainless nights with mild temperatures (Falxa 2007).

Migrating bats fly only at night. Migrants in Manitoba emerged from roosts typically 30 minutes after sunset in spring (Barclay et al. 1988). Roosting migrants in Manitoba became torpid at air temperatures below 20 C (Barclay et al. 1988).

This species is similar to most insectivorous, temperate-zone bats in becoming torpid during periods of reduced prey availability and temperature; individuals may hibernate to maintain energy balance during winter (Dunbar 2007).
Provincial Phenology:
(1st half of month/
2nd half of month)
Colonial Breeder: N
Length(cm)/width(cm)/Weight(g): 11/ / 15
Elevation (m) (min / max): Global: 
Provincial: 
   
 
Distribution
Endemic: N
Global Range Comment: Range extends from southeastern Alaska (Blejwas et al. 2014) and southern Canada south of the Northwest Territories southward to California, Arizona, Texas, and east to Georgia (Yates et al. 1976, Hall 1981, Kunz 1982). There are also limited records from Bermuda (Van Gelder and Wingate 1961) and northern México (Arriaga Flores 2010). These bats are generally absent in the southeastern United States during summer (June- August; Cryan 2003). In Texas, they appear to be primarily spring and fall migrants, though males have been found in mountainous areas of western Texas in May-June (Ammerman et al. 2012). They winter in the Pacific Northwest, in scattered areas of the southwestern United States, and at middle latitudes of the eastern United States approximately south of Michigan and east of the Mississippi River (Izor 1979, Cryan 2003). Males seem to stay farther south in spring and summer than do females, except for populations in British Columbia that do not appear to migrate (Schowalter et al. 1978, Cryan 2003). Using Global Biodiversity Information Facility (GBIF) (2025) records from 2005-2025, range extent is estimated to be 14.75 million km² (RARECAT 2025).
 
Authors / Contributors
Global Information Author: Hammerson, G.
Last Updated: Apr 01, 2015
Provincial Information Author:
Last Updated:
   
References and Related Literature
Baker, R. H. 1983. Michigan mammals. Michigan State University Press. 642 pp.
Barbour, R. W., and W. H. Davis. 1969. Bats of America. The University of Kentucky Press, Lexington, Kentucky. 286 pp.
Barclay, R. M. R., P. A. Faure, and D. R. Farr. 1988. Roosting behavior and roost selection by migrating silver-haired bats (Lasionycteris noctivagans). Journal of Mammalogy 69:821-825.
Barclay, R.M., and R.M. Brigham, eds. 1996. Bats and Forests Symposium. B.C. Minist. For. Res. Program, Working Pap. No. 23. 292pp.
Caire, W., J. D. Tyler, B. P. Glass, and M. A. Mares. 1989. Mammals of Oklahoma. University of Oklahoma Press, Norman. Oklahoma. 567 pp.
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.
Godin, A. J. 1977. Wild mammals of New England. Johns Hopkins University Press, Baltimore. 304 pp.
Hall, E. R. 1981a. The Mammals of North America, second edition. Vols. I & II. John Wiley & Sons, New York, New York. 1181 pp.
Hamilton, W. J., Jr., and J. O. Whitaker, Jr. 1979. Mammals of the eastern United States. Cornell Univ. Press, Ithaca, New York. 346 pp.
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.
Kunz, T.H. 1982. Lasionycteris noctivagans. Am. Soc. Mamm., Mammalian Species No. 172. 6 pp.
Lausen, C, D.W. Nagorsen, R. M. Brigham and J. Hobbs. 2022. Royal Museum Handbook. Bats of British Columiba. Second Edition. Royal BC Museum. Victoria, Canada. 375 pp.
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.
Padgett, T. M., and R. K. Rose. 1991. Bats (Chiroptera: Vespertilionidae) of the Great Dismal Swamp of Virginia and North Carolina. Brimleyana 17:17-25.
Parsons, H. J., D. A. Smith, and R. F. Whittam. 1986. Maternity colonies of silver-haired bats, Lasionycteris noctivagans, in Ontario and Saskatchewan. Journal of Mammalogy 67:598- 600.
Ports, M. A., and P. V. Bradley. 1996. Habitat affinities of bats from northeastern Nevada. Great Basin Naturalist 56:48-53.
Reimer, J. P., E. F. Baerwald, and R.M.R. Barclay. 2010. Diet of hoary (Lasiurus conereus) and silver-haired (Lasionycteris noctivagans) bats while migrating through southwestern alberta in late summer and autumn. American Midland Naturalist 164:230-237.
Schmidly, D. J. 1991. The bats of Texas. Texas A & M University Press, College Station, Texas. 188 pp.
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.
Vonhof, M. J., and R.M.R. Barclay. 1996. Roost-site selection and roosting ecology of forest-dwelling bats in southern British Columbia. Canadian Journal of Zoology 74:1797-1805.
Vonhof, M.J., and J.C. Gwilliam. 2000. A Summary of Bat Research in the Pend dOreille Valley in Southern British Columbia. Columbia Basin Fish and Wildlife Compensation Program, BC Hydro, B.C. Minist. Environ, Lands and Parks, B.C. Fish. in partnership with B.C. Minist. For. 116pp.
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/.
 

Please visit the website Conservation Status Ranks for definitions of the data fields used in this summary report.

Suggested Citation:

B.C. Conservation Data Centre. 2015. Species Summary: Lasionycteris noctivagans. B.C. Minist. of Environment. Available: https://a100.gov.bc.ca/pub/eswp/ (accessed Oct 22, 2026).