Wisconsinites encouraged to take action during International Bat Week

WISCONSIN – The Wisconsin Department of Natural Resources is (DNR) encouraging Wisconsinites to take action to help bats during International Bat Week and throughout the year.

This year, International Bat Week will be observed from Saturday, Oct. 24 through Saturday, Oct. 31.

“The only flying mammals, bats are unique and fascinating – they’re also extremely important members of our natural world,” the DNR said in a release. “They are vital to many ecosystems and provide significant positive environmental, economic and public health benefits. For example, insectivorous (bug-eating) bats consume large numbers of agricultural pests, saving farmers and forest-owners billions of dollars every year.”

Of the eight bats found in Wisconsin, four are state-threatened species: big brown bat, little brown bat, northern long-eared bat (also federally endangered) and tricolored bat; and one, the silver-haired bat, is of special concern, meaning the population is declining and in need of conservation action, according to the DNR.

The DNR said the decline of bats in Wisconsin is primarily due to white-nose syndrome, a disease caused by a fungus that attacks the bare skin of bats during hibernation each winter. The disease exhausts their energy stores and leaves them vulnerable to starvation before their insect diet becomes available in the spring.

“Fortunately, after experiencing steep declines since 2014, when white-nose syndrome first arrived in Wisconsin, recent Wisconsin Bat Program survey counts show rebounding numbers of little brown bats at some significant roost and hibernation sites across the state,” the DNR stated. “Many of these sites offer ideal conditions for little brown bats and were known to hold large numbers before white-nose syndrome arrived in the state.”

"Just a few of Wisconsin’s historic mines are the winter home to a significant percentage of the nation’s little brown bats," said Jennifer Redell, DNR Conservation Biologist and Bat Program Hibernacula Specialist. "In the spring, those bats emerge to spread out across thousands of square miles of forests, fields and neighborhoods in the Midwest. Keeping those hibernating bats safe when they’re here in winter should be of interest to everyone who wants to swat at fewer mosquitoes each summer."

Despite the recent glimmers of population recovery in little brown bats, there's still a long way to go, the DNR noted. Hibernating bats are still stressed by white-nose syndrome each winter, and species like the tricolored bat and northern long-eared bat have not shown similar signs of recovery.

The DNR provided the following tips to help backyard bats:

• Learn how you can build your own bat house.
• Plant native plants that are foundational to a healthy backyard ecosystem.
• Control burdock on your property, which can fatally entangle bats and small songbirds. After burdock has gone to seed, avoid composting, which may allow it to spread.
• Maintain an insecticide and herbicide-free yard. They can harm bats through the food they eat.
• In outbuildings and basements frequented by bats, keep buckets overturned or on their sides to avoid trapping bats and other small mammals.

The DNR also provided the following volunteer and support opportunities:

• Check org's Events webpage and search "Wisconsin" to find an event near you!
• Become a Wisconsin Bat Program volunteer and participate in roost or acoustic monitoring.
• Sign up for email updates about bats and bat conservation.
• Donate to the Endangered Resources Fund to support threatened and endangered species and habitat protection in Wisconsin.
• Visit the Wisconsin Bat Conservation Network's website for updates and more opportunities. 

For more information about bats, visit the Wisconsin DNR’s bat frequently asked questions webpage.