Wisconsin’s occurrence databases hold 390 southern flying squirrel records, spread fairly evenly across the year rather than clustering around any one season, and nearly all of them come from strictly nocturnal encounters.
Gliding between old cavity trees
A southern flying squirrel needs mature hardwood forest with enough old, cavity-riddled trees, remnants of old woodpecker work or natural rot, to den in and to launch a glide from. The oak, beech, and maple stands of Kettle Moraine State Forest and the mixed hardwood-conifer forest of the Chequamegon-Nicolet National Forest both hold that kind of older canopy, letting a squirrel stretch its gliding membrane and cover 18 to 30 feet between trunks in a single silent run.
Huddled together through a Wisconsin winter
Unlike most tree squirrels, southern flying squirrels den together in groups during the coldest months, sometimes a dozen or more sharing one tree cavity for warmth, a behavior that becomes especially useful through a Wisconsin winter. Because the species is active only after dark and spends its days sealed inside a hollow trunk, most Wisconsin records come from bait-station surveys, nest box checks, or a chance flashlight beam rather than a daytime sighting.
Status in Wisconsin
NatureServe ranks the southern flying squirrel S4, apparently secure, in Wisconsin, and it’s native to the state. It depends on the same older, cavity-rich forest wherever it occurs here, from the hardwoods ringing Horicon’s marsh to the deep stands of the Chequamegon-Nicolet.
