Species: Myotis lucifugus

Little Brown Myotis

Species

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Encyclopedia of Puget Sound

Cinnamon-buff to dark brown above, buffy to pale gray below; hairs on back have long glossy tips; ear when laid forward reaches approximately the nostril; tragus about half as high as ear; calcar without keel; length of head and body 41-54 mm, ear 11.0-15.5 mm, forearm 33-41 mm; braincase rises gradually from rostrum; greatest length of skull 14-16 mm; length of upper toothrow 5.0-6.6 mm (Hall 1981).

Articles:

Little Brown Myotis (Myotis lucifugus)

June 01, 2013

This article originally appeared in the State of Washington Bat Conservation Plan. Further information is available from the Washington Department of Fish and Wildlife.

Image copyright Merlin D. Tuttle, Bat Conservation International, www.batcon.org

Report: Washington State Bat Conservation Plan

May 18, 2013

The Washington Department of Fish and Wildlife recently released a Bat Conservation Plan for the 15 species of bats found in Washington State. All but four of these species occur within the greater Puget Sound watershed1, including:

Fringed Myotis. Photo © Merlin D. Tuttle, Bat Conservation International, www.batcon.org

Classification

Kingdom

Animalia

Phylum

Craniata

Class

Mammalia

Order

Chiroptera

Family

Vespertilionidae

Genus

Myotis

NatureServe

Source:
ELEMENT_GLOBAL.2.100473

Classification

Other Global Common Names

Little Brown Bat - Un Murciélago - petite chauve-souris brune - vespertilion brun

Informal Taxonomy

Animals, Vertebrates - Mammals - Bats

Formal Taxonomy

Animalia - Craniata - Mammalia - Chiroptera - Vespertilionidae - Myotis - may be polyphyletic (J. Hayes, pers. comm. 2004).

Ecology and Life History

Short General Description

A small brown bat.

Migration

false - true - true - In the northeast, may migrate hundreds of miles between winter and summer habitats; in the west, believed to hibernate near their summer range (Schmidly 1991).

Non-migrant

false

Locally Migrant

true

Food Comments

Often hunts over water or along the margins of lakes and streams; consumes flying insects, especially mosquitoes, midges, caddisflies, moths, various hoppers, and smaller beetles, sometimes spiders (e.g., see Whitaker and Lawhead 1992). Insects with wingspans of 1/8-1/2" are pursued (Schwartz and Schwartz 1981). Prey are detected by echolocation at a range of 1 m (Fenton and Bell 1979).

Reproduction Comments

Usually mates in September-October. Ovulation and fertilization are delayed until spring. Gestation lasts 50-60 days. Gives birth to 1 litter of 1 young, late spring-early summer. Females produce first young usually in first (Indiana, New Mexico) or second year (British Columbia) (Herd and Fenton 1983). In British Columbia, may delay or forego reproduction in wet years (Grindal et al. 1992). Survival for a decade may be fairly common; a few live as long as 20-30 years; females may be reproductive to an age of at least 12 years (Hall et al. 1957, Keen and Hitchcock 1980). Most summer colonies range from 50 to 2500 individuals (average 400) (Mumford and Cope 1964).

Ecology Comments

Winter concentrations may include tens of thousands. Summer home range is poorly understood. Experiences low survival during first winter, higher in subsequent years.

Length

Weight

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

2008-01-14

Global Status Last Changed

1996-11-04

Other Status

LC - Least concern

Distribution

Conservation Status Map

Global Range

H - >2,500,000 square km (greater than 1,000,000 square miles) - H - Wide range includes North America from the Alaska-Canada boreal forest south through most of the contiguous United States, though the species is generally absent fom the southern Great Plains region. Southwestern populations formerly assigned to this species have now been assigned to <i>M. occultus</i> (Piaggio et al. 2002; Wilson and Reeder 2005), so the southwestern boundary of the range includes southern California (except extreme southeast), Nevada, northern Utah, northern Colorado, and perhaps northeastern New Mexico (Piaggio et al. 2002; Valdez, pers. comm.).<br><br>The high density of caves in the Appalachian Mountain range and eastern Midwest (Culver et al. 1999) likely "support much larger populations of this species than in other parts in the species' range. The largest known colonies of little brown myotis are in the northeastern and mid-western United States, with the northeastern population considered the core range of the species" Kunz and Reichard 2010). Smaller populations occur in the southern and western United States (Davis et al. 1965).

Global Range Code

Global Range Description

>2,500,000 square km (greater than 1,000,000 square miles)

ELEMENT_GLOBAL.2.100473