|    New Jersey Division of Fish and Wildlife|
New Jersey's largest known bat hibernaculum is the Hibernia Mine in Rockaway Township, Morris County. The 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 mine continued to provide winter habitat for bats but frequent and constant human disturbance limited the mine's potential. Over the years a number of unsuccessful attempts were made by landowners to seal the mine to keep people out. However, sealing the mine would have also made it unavailable to the bats.
In July of 1994, the Endangered and Nongame Species Program successfully negotiated a long sought after agreement with landowners to install a special bat conservation gate to keep people out but allow free access by the bats. The gate was designed by Roy Powers of Virginia and constructed through the joint efforts of Powers, the ENSP, the US Fish and Wildlife Service and Bat Conservation International. Shortly after the gate was installed the state acquired the property through the Green Acres Program and it is currently part of the Wildcat Ridge Wildlife Management Area and is listed as a Watchable Wildlife Site.
The ENSP conducts a biennial winter survey to assess the bat population in the Hibernia Mine. The most recent survey occurred in February 1999 when more than 30,000 bats were counted - the largest total since bat surveys began in the mine. Beginning in 2003, a Summer Bat Count was begun to document summer roosting locations throughout New Jersey and help to create a range map for the state's nine species of bat. The information will also help to determine roosting and foraging requirements and contribute to the protection of bats in New Jersey.
In 1997, the ENSP began a project to search for and protect additional mines and tunnels that support wintering bat populations. A number of new hibernacula have already been located and efforts are underway to protect them. In November 1999 a bat conservation gate was constructed and installed over the entrance to a tunnel in Worthington State Forest in Warren County. The gate was completed through the cooperative efforts of the ENSP, the Division of Parks and Forestry and the US Army Corps of Engineers. The site currently supports several hundred wintering bats but has the potential to support a much larger population. Time will tell if protecting the bats from human disturbance will allow the wintering population to increase. The ENSP will continue to search for and protect habitats that are important to bats.