Big Brown Bats (Eptesicus fucus)
This adaptive bat species is able to make its’ home in a wide range of different areas of North America. They are most abundant in deciduous forests, but this is not the limits to the environments in which they can inhabit. They can be found in all sorts of habitats from urban to suburban, timberline meadows to lowland deserts, and any in between. Their range stretches from northern Canada, throughout the contiguous United States, and down to the southern tip of Mexico.
Color and Size
As their name suggests, they range in color from light to dark brown with black on their ears, muzzle, and wing membranes. Their long fur tends to have an oily texture. They have short ears, broad muzzles, and a furless tail membrane. The brown bat has a wingspan of 13 to 16 inches wide, range in length (including body and tail) from 4 to 5 inches, and can weigh about ¾ of an ounce.
Diet and Behavior
Brown bats are insectivores that are not particular about the areas in which they hunt. They will hunt over water, forested areas, clearings, or land. These bats are also considered to be generalists who will eat whatever flying insects are available for their consumption including beetles, stink bugs, moths, and leafhoppers. They are a migratory species that will travel hundreds of miles, but it is known that the southern populations will be year-round residents because of the stable temperatures in these areas.
They will roost and hibernate in tree crevices and hollows, bat houses, mines, barns, rock crevices, under bridges, or caves. They choose their roosting sites depending on their needs for the given season and time of year. These bats mate just before they go into hibernation and the females do not become pregnant until the springtime when they emerge. The females will form maternity colonies in the spring of up to 300 females in order to rear their young.