04/24/2026
Of the eight bat species found in Wisconsin, four are state-threatened. One of these, the little brown bat (Myotis lucifugus), is showing rebounding numbers, thanks in part to the habitats found in state natural areas.
In summer, little brown bats may roost in tree snags, bat houses and buildings across Wisconsin. But come fall, many of them head to a few SNAs, where they can find very specific habitat to use from October through April.
Unlike the other examples on this list, however, the bat habitat at SNAs isn't a holdover of Wisconsin's native landscapes. It's a byproduct of industrialization – abandoned mines, to be specific.
Two large mines in particular, both within state natural areas, provide the vast majority of shelter for little brown bats overwintering in the state. Despite being relics of industry, these sites offer ideal conditions critical to a significant proportion of the nation's little brown bats.
Learn more about Wisconsin's State Natural Areas and the remarkable species they help protect in the latest issue of Wisconsin Natural Resources magazine: https://issuu.com/wisconsinnaturalresources/docs/wisconsin_natural_resources_magazine_spring_2026/s/154416529
Photo Credit: Heather Kaarakka