Our Maine Street's Aroostook Issue 18 : Fall 2013 - Page 66

throughout the winter. Additional roosting substrates were placed in the bunker to permit the bats a greater diversity of objects to hang from (i.e. hollow log, bat house, wire mesh, plastic mesh and nylon netting). In late December of 2012, 30 infected little brown bats were brought to the bunker from Vermont and New York. The bats spent the winter in the sealed bunker and were monitored throughout their three month hibernation with the infrared cameras. In late March, state and federal biologists from New York, New Hampshire, Vermont, and Maine returned to the bunker to collect the bats and return them to their native hibernacula from which they came. The survival rate of bats in the bunker (30%) was similar to that seen in natural hibernation sites. The U.S. Fish and Wildlife Service is currently working on sterilizing the infected bunker. The structure will be scrubbed with a solvent and then steam pressure washed to remove any remaining solvent. Genetic swabs are being taken before and after the sterilization process to determine if the fungus was successfully destroyed. A social attraction system to attract bats to the bunker will be installed this fall. The ultrasonic audio transmitter will broadcast bat ‘swarming’ calls to attract bats to the retrofitted structure, with the hope that bats will overwinter in the sterilized structure. A bio-acoustic monitoring device will be installed in the bunker to record bat activities throughout the year. The need to remove infected bats from the wild and place them in a temporary site where they could hibernate in a cleaner environment highlights the dire situation that bats now face in the northeast. The project shows that little brown bats can survive being transported during hibernation through multiple states and that bats can survive overwintering in an artificial hibernaculum such as a military bunker. Retrofitted bunkers in northern Maine may very well serve as bat hibernacula in future years or as mitigation facilities in cases of further fungal or disease outbreaks. Aroostook National Wildlife Refuge is managed by the U.S. Fish and Wildlife Service. The refuge is open from sunrise to sunset, seven days a week. More than 13 miles of hiking and skiing trails are available to the public free of charge. If you have questions regarding the project or about Aroostook National Wildlife Refuge, please call (207) 328-4634. 66 FALL 2013