The little brown bat’s Ohio records spike hard in July and August, when the monthly count jumps well above every other month, then fall off sharply through fall. That’s the signature of maternity colonies: females roost together to raise pups through early summer, and once the young are flying, colonies become far easier for observers to detect and record. Outside that window, sightings are scarce. Ottawa National Wildlife Refuge, Killdeer Plains Wildlife Area, and Mentor Marsh give a sense of the wetland and edge habitat this species forages over, though where it actually roosts and hibernates is a separate question the occurrence map doesn’t fully capture.
Ohio’s 255 records sit against a grim backdrop. Little brown bats have crashed across the eastern United States, Ohio included, since white-nose syndrome, a fungal disease that attacks hibernating bats, arrived in the region and killed the large majority of the population at many hibernation sites. Ohio’s NatureServe rank is S1, critically imperiled, and the species is native to the state. The sharp summer spike in records is a real window into an active maternity season, not evidence the population has recovered.
Full species profile
