The tricolored bat is easy to miss even where it’s holding on. Illinois records cluster around Cache River State Natural Area, Chautauqua National Wildlife Refuge, and the wooded backwaters along the upper Mississippi River, the kind of forested wetland edges this bat favors for roosting. Statewide reports stay thin, just 123 logged since 2000, and NatureServe hasn’t assigned Illinois populations a conservation rank at all, listing the species SNR, unranked, which says more about how hard this bat is to survey than about how many remain.
Illinois sightings turn up across most of the year, clustering most in April. That’s a reporting pattern, not proof the bat is busier then; a small, weak-flying species like this one gets noticed more easily once trees leaf out and more people are outdoors watching for it.
Nationally, this fist-sized bat has lost whole hibernating colonies to white-nose syndrome, a fungal disease that has emptied roosts across the East and made this once-widespread bat one of the country’s fastest-declining.
Full species profile
