The big brown bat is found in southern Canada, across the United States and Central America, and in northern South America. As its name implies, it is one of the larger bats found in North America, with an average total length between 110-130 mm and an average wingspan of 330 mm.

 

Big brown bats, prior to extensive human alteration of the environment, would roost in tree hollows, caves, or rock ledges. Now, the primary roosting habitat for the species includes human dwellings, churches, barns, silos, and even abandoned copper mines.  

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The species is insectivorous. Its primary prey is beetles, but it consumes a wide variety of flying insects which it uses echolocation to track and capture. Because of its dependence on prey available only during warmer months, the big brown bat is a hibernating species. 

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This hibernating behavior makes the big brown bat vulnerable to white-nose syndrome present in temperate regions of North America. Big brown bats have seen a decrease in Connecticut, and the species is currently listed in Connecticut's Wildlife Action Plan as a Species of Greatest Conservation Need.