Kansas’s little brown bat records carry an unusual fingerprint: the single heaviest month is December. That’s the signature of winter hibernation surveys, biologists counting bats in the caves and mines where the species spends the cold months. Marshall County in the northeast corner dominates the record with 44 of 69 reports, followed by Crawford, Douglas, and Leavenworth counties, all in the state’s eastern third.
Summer reports exist, spread from March through October, but the winter weight tells you where the survey effort has gone. It also hints that Kansas matters to this bat as hibernation country, not just summer range.
The official standing is sobering. NatureServe ranks the species S3, vulnerable, in Kansas, and the IUCN lists it as Endangered globally after white-nose syndrome collapsed populations across the East. A bat that was once ordinary over farm ponds and town lights now earns a conservation rank in nearly every state where it’s tracked, Kansas included.
Full species profile
