Looking for Bats

By: Licia Johnson

The Bat Crew with the WI Department of Natural Resources down in Madison have been working hard this summer trying to locate the Northern Long-Eared Bat (Myotis septentrionalis).  It is one of the four bats listed in WI as threatened, due to the fact that they hibernate in caves and mines and therefore are susceptible to White Nose Syndrome.  For more on WNS please visit www.whitenosesyndrome.org.  This is a bat not very common in Wisconsin, and has been recently looked at to be placed on the federally endangered species list.  Bat biologists have spent most of the summer traveling around the state in search of this elusive bat.  Visiting different sites, they go out at night and attempt to mist net the bats as they fly through the forest.  These are small nets that will catch the bats, allowing the biologists to remove, weigh, measure and examine the bat. The goal is to locate the Northern Long-Eared bat (specifically lactating females), put a small transmitter on their back, and later locate them using radio telemetry equipment at their roosting sites.  These females roost alone or with a few other females under tree bark and in crevices, and rarely in man-made structures.  We were lucky enough here at the Discovery Center to host a group of biologists who were studying these animals at nearby sites in the Northern Highland American Legion State Forest.  I was further lucky enough to join them one evening in June on one of their excursions…

We broke into three teams, each in a different location.  We set up the mist nets and then waited.  Throughout the night we caught many bats, at my station they were all Little Brown Bats.  They were removed from the nets, weighed, measured, checked for signs of wing membrane deterioration and then released.  We had a few males, one lactating female and one very pregnant female, which was interesting this late in the season.  

  

Caption: All captured bats were measured (forewing), weighed in a pill container and checked for wing membrane deterioration.  (photos by Licia Johnson)

 One group did manage to catch a Northern Long-Eared Bat and put a transmitter on her.   

Caption: Each bat gets tagged with a transmitter that is less than 5% its body weight. The tag is attached using non-toxic surgical glue that comes off after a couple weeks.  The transmitter batteries last 5-10 days. (WDNR PHOTO)

  (moth photo by Licia Johnson, squirrel photo WDNR)

There were a few critters that managed to get caught in the nets during the night, including Prometheus Moths and Flying Squirrels- all released without harm!

The Wisconsin Bat Crew finished up their studies earlier this month.  More information to come on what they found.  For more information on the federal listing of the Northern Long-Eared Bat please visit: http://www.fws.gov/midwest/endangered/mammals/nlba/