Species: Eptesicus fuscus

Big Brown Bat

Species

Mammals

Show on Lists

Terrestrial vertebrates: mammals

Encyclopedia of Puget Sound

Articles:

Big Brown Bat (Eptesicus fuscus)

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

Eptesicus

NatureServe

Source:
ELEMENT_GLOBAL.2.105810

Classification

Other Global Common Names

Un Murciélago - grande chauve-souris brune - sérotine brune

Informal Taxonomy

Animals, Vertebrates - Mammals - Bats

Formal Taxonomy

Animalia - Craniata - Mammalia - Chiroptera - Vespertilionidae - Eptesicus - that are chromosomally characterized by 2n=50 and FN=48 form a genetically homogeneous group, despite the included taxa coming from different continents (Hill and Harrison 1987, Morales et al. 1991).

Ecology and Life History

Short General Description

A large brown bat.

Migration

true - false - false - Fairly sedentary. Probably remains within 50 km of birthplace (Barbour and Davis 1969). Rarely moves more than 80 km between summer and winter roosts, though there is evidence that some individuals in the Midwest migrate south for winter.

Non-migrant

true

Locally Migrant

false

Food Comments

Dependent upon flying insects; small beetles are the most common prey in many areas. Large size, powerful jaw muscles, and robust teeth allow predation on larger insects with tough exoskeletons (e.g., beetles). Basically a generalist in foraging habitat; forages over land or water, clearings and lake edges; may forage around lights in rural areas. According to Schmidly 1991, seems to prefer foraging among tree foliage rather than above or below the forest canopy. Distance from day roost to foraging area averages about 1-2 km (Brigham 1991).

Reproduction Comments

Copulates in fall and intermittently throughout winter. In temperate regions, ovulation and fertilization delayed until after hibernation. Gestation lasts 2 months. Young are born May-July, with slight trend toward earlier parturition in lower latitudes (Barbour and Davis 1969); mostly late May to June in Texas (Schmidly 1991). Litter size usually is 1 in western North America, 2 in eastern North America and Cuba. Lactation lasts 32-40 days; young fly at 4-5 weeks. Males usually are sexually mature in first fall; not all females reproduce at end of first year. Nursery colony rarely numbers more than a few hundred (mostly 25-75 adults in the eastern U.S.).

Ecology Comments

Males most often solitary in summer, or may roost with females or in all-male colonies. Winter colonies rarely number more than a few hundred. Less gregarious in winter; usually solitary in crevice, sometimes in small groups. When young flying, males may join nursery groups to form large late-summer colonies (Barbour and Davis 1969). Capable of living at least 20 years, though few actually attain old age.

Length

Weight

Conservation Status

NatureServe Global Status Rank

Global Status Last Reviewed

1996-11-05

Global Status Last Changed

1996-11-05

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 - Range extends from southern Canada (including all provinces bordering the United States) south to northern Colombia, northwestern Venezuela, and northern Brazil; all Mexican states except those of Yucatan Peninsula (in northern Mexico most prevalent in eastern and western Sierra Madre bordering arid midlands of Mexican Plateau); in and along central mountain chain in Central America; Greater Antilles; Bahamas; Dominica and Barbados in Lesser Antilles; perhaps Alaska (Honacki et al. 1982; Kurta and Baker 1990; Jones 1989; Koopman, in Wilson and Reeder 1993).

Global Range Code

Global Range Description

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

ELEMENT_GLOBAL.2.105810