Little Brown Bat (Myotis lucifugus)



(Thank-you to Dr. Merlin Tuttle, Bat Conservation International for use of this picture)


The little brown bat is the most common bat in Alberta, Canada and the United States. It is estimated that there are 1.5 million of these bats in Alberta. Adult little brown bats average 8.5 g (0.3 oz) and have a wing span of only 20 cm (8 inches). Its fur colour varies from yellow or olive to blackish, with the fur on the underside lighter. The wing membranes and ears are dark brown. These bats have the greatest altitudinal range of any Canadian bat, as high as 2288 m ASL (7506 ft ASL). They tend to roost anywhere that they find appropriate - from houses to trees, to rock cavities! Females tend to congregate in nursery colonies preferring temperatures in the 30˚C to 55˚C range. Mating takes place in late summer or early fall, prior to hibernation. Gestation is from 50 to 60 days, and a single young is born. Newborns weigh about 1 to 1.5 grams, and they will fly in only 3 weeks! These bats are one of the longest lived mammals for it's size - up to 33 years!