Myotis septentrionalis, known as the northern long-eared bat or northern myotis, is a species of bat native to North America. There are no recognized subspecies. The northern long-eared bat is about 3–3.7 inches in length, with a wingspan of 9–10 inches. It is distinguishable by its long ears when comparing it to other bats in its genus. This species is commonly found in the northern United States and Southern Canada east of British Columbia. The geographic range includes 37 states. Description The northern long-eared bat is a small bat, measuring an average of in total length, including a tail about long. Adults weigh between . The fur and wing membranes are light brown in color, and the bat lacks the dark shoulder spots found in the closely related, and otherwise similar Keen's myotis (Myotis keenii). Compared to other Myotis species, these bats have long ears with a relatively long, pointed tragus; when folded forwards the ears extend well past the nose. They also have a longer tail and larger wing area than most comparably sized Myotis bats, giving them increased maneuverability during slow flight. Distribution and habitat Northern long-eared bats are found through much of the eastern half of the United States and Canada from Manitoba and Newfoundland in the north to North Carolina and Alabama in the south. They are also rarely found in western parts of Canada, sometimes as far as the western borders of British Columbia and Yukon. They are found primarily in forested habitats, especially boreal forests, as they typically roost in hardwood trees during the summer. Biology and behavior During the spring and summer, northern long-eared bats spend the day roosting in trees or artificial structures, switching to a new roost every other day on average. Roost trees tend to be close together, and within about of areas suitable for foraging. Males and non-reproductive females roost singly or in small groups, but reproductive females and their young form much larger maternity colonies, with up to sixty individuals. In the fall, northern long-eared bats migrate to caves to hibernate. Depending on the latitude, this may occur at any time between September and November, and the bats emerge between March and May. They typically hibernate together with much larger numbers of bats of other species, although hibernating groups of northern long-eared bats may still number in the hundreds. Northern long-eared bats are well-suited to foraging in the