State bat biologists are calling on the public to report the barns, buildings, bat houses and other roosts where surviving bats are showing up. Recent surveys show the bat disease white-nose syndrome has reduced bat populations to zero at some hibernation sites and decreased others by 72 to 97 percent.
Paul White leads the team at the DNR working with bat populations. White-nose syndrome is a fungal disease affecting only bats. It wakes them up during hibernation and they quickly use their energy reserves and die. Wisconsin has been infected since 2014. He says sites that had a thousand or more bats had none hibernating this year.
Losses to agriculture because of more insects are thought to be in the millions of dollars.
White says researchers initially thought the disease was the end of the bat population here, but there have been survivors...
"...The fact that we're still seeing bats is somewhat exciting for us, even though they're low populations of what they used to be. We're starting to see some sight characteristics that provide an adequate place for bats to hibernate despite having infection and fungus. We're trying to understand what those site characteristics are and how we can implement those at other sites to make sure that other populations are still persisting..."
Volunteers are needed for the Great Wisconsin Bat Count, held May 31-June 2 and July 19-21. The first statewide count is conducted before young bats, called "pups," are able to fly and the second count occurs after pups are flying on their own. Volunteers identify bat roosts and sit outside the roost entrance in the evening to count the bats as they emerge just after sunset and report those results to DNR.
We have a link to the DNR's bat program website.