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 [phone].
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FALL 2013