April 7, 2015
MADISON--With winter nearly over, bats will emerge from hibernation and return to their summer roost sites--this makes early spring a good time to construct a bat house.
"Building a bat house is a great way to provide important habitat during a critical time for bats," said Heather Kaarakka, bat roost monitoring coordinator with the Wisconsin Department of Natural Resources. "Encouraging bats to take up residence on your property is a great way to help reduce forest and garden pest populations."
Those interested in building a bat house on their property can follow the instructions and guidelines in the department's "Building a Bat House [PDF]" handbook. This guide provides information regarding necessary supplies and materials, and also includes key design, location and mounting specifications.
Wisconsin's four cave bat species are listed as threatened, due to their vulnerability to white-nose syndrome. The bats' threatened status makes it illegal to begin the process of excluding bats from buildings from June 1 to Aug. 15, when bats may seek to roost in attics, barns and other warm places to give birth and nurse their young.
According to Kaarakka, it is important to begin the eviction and exclusion process now to avoid any conflicts with maternity season. Bat pups are born in early June and are unable to fly for several weeks. Separating a mother from her pups will cause the pups to die, and frantic mothers searching for their pups often find themselves in living spaces.
It's important that people who do not want bats in their buildings follow the necessary steps to safely and humanely remove bats and seal off bat entry points by June 1. DNR's Bat Exclusion guide [PDF] provides instructions for excluding bats from an attic or other structure. Those who do not want to take the exclusion steps themselves can contact professional bat exclusion experts.
In addition to habitat creation, people can also join the department's roost monitoring project. When you have selected suitable habitat and constructed a bat house, you can monitor the roost entrance in June and July and count bats as they emerge. For more information on bat roost monitoring or to join the program, visit the Wisconsin Bat Program (exit DNR) page.
The DNR conducts a number of bat monitoring projects in order to better understand population trends and health status. Information on location and size of bat colonies is critical to the success of these surveys, says Kaarakka.
If you know of large numbers of bats in caves, mines, barns, bridges, churches, schools or other buildings, please contact the Wisconsin Bat Program at DNRbats@wisconsin.gov or 608-266-5216.
Join Wisconsin Department of Natural Resources experts for an online chat Thursday, April 23 at noon and learn more about bats in Wisconsin. Search the DNR website, dnr.wi.gov, for keyword "chat" to submit questions and view responses from DNR experts. Here, you can also view past chats and sign up to receive email notifications.
FOR MORE INFORMATION CONTACT: Heather Kaarakka, DNR roost monitoring coordinator, 608-266-2576; Paul White, DNR mammal ecologist, 608-267-0813