New Jersey Bats: According to New Jersey Fish and Wildlife GOV
New Jersey has nine species of bats that are considered regular residents of New Jersey. These New Jersey bats include the little brown bat, big brown bat, northern long-eared bat, small-footed myotis, the New Jersey Eastern pipistrel, the New Jersey Indiana bat (state and federally endangered), hoary bat, red bat and silver-haired bat. The New Jersey hoary, red and silver-haired bats are part-time New Jersey residents that are found here from spring through fall when they migrate to southern states for the winter. The other New Jersey six species remain here throughout the entire year and require special habitats for winter hibernation. New Jersey natural caves once provided hibernating habitat for bats, but today most caves are subject to disturbance by people and thus are not suitable for use by New Jersey bats. Abandoned New Jersey mines and tunnels have replaced natural caves as the primary winter habitat for bats in many parts of the country because they are often unsafe to enter or inaccessible to people.
New Jersey’s largest known bat hibernaculum is the New Jersey Hibernia Mine in Rockaway Township, Morris County. The New Jersey mine was abandoned in the early 1900s and the first record of bats using the mine is from the 1930s. In the decades that followed, the New Jersey mine continued to provide winter habitat for bats but frequent and constant human disturbance limited the New Jersey mine’s potential. Over the years a number of unsuccessful New Jersey attempts were made by landowners to seal the mine to keep people out. However, sealing the New Jersey mine would have also made it unavailable to the bats.
Two kinds of New Jersey bats in our area are often found roosting in colonies inside buildings, the big brown and little brown bats. Other bats, called New Jersey solitary bats, do not usually enter buildings.