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Smithsonian National Museum of Natural History, North American Mammals

  Chiroptera · Vespertilionidae · Lasiurus borealis

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Lasiurus borealis

Eastern Red Bat

Order: Chiroptera
Family: Vespertilionidae

Image of Lasiurus borealis
Lasiurus borealis - female (left) and male (right)
Click to enlarge. (98 kb)

Conservation Status: Least Concern.

Common and widespread from far southern Canada throughout most of the United States and Mexico, and farther south through Central America and into South America, the Eastern Red Bat requires trees and shrubs for roosting. It is remarkable for its richly-colored reddish pelage, with the male brighter than the female. Although the Eastern Red Bat is solitary, it migrates in groups. Females often give birth to twins and sometimes to quadruplets. The young are born hairless, with eyes closed, and weigh only 0.5 g, but by 3-6 weeks they are covered with fur, have their eyes open, are half their mother's weight, and can fly.

Also known as:

Red Bat

Sexual Dimorphism:

Females are larger than males.


Average: 112.3 mm
Range: 95-126 mm


Range: 7-16 g


Muller, P.L.S., 1776.  Mit einer ausfuhrlichen erklarung ausgefertiget. Des ritters Carl Von Linne…Vollstandigen natursystems supplements and register-ban uber aller sechs theile oder classen des thierreichs, G.N. Raspe, Nurnberg, pp. 3-34.


Mammal Species of the World (opens in a new window).

Mammalian Species, American Society of Mammalogists' species account * (opens in a new window).
* PDF reader available here (opens in a new window).

Distribution of Lasiurus borealis

Image of Lasiurus borealis
Click to enlarge. (162kb)

Image of Lasiurus borealis
Click to enlarge. (125kb)

Skull of Lasiurus borealis
Click to enlarge. (24kb)

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