Illinois holds the single largest share of confirmed southern bog lemming records of any state, 73 out of a national total of 165. That’s a striking count for an animal that hides its whole life under matted grass and rarely turns up without a trap or an owl pellet to give it away.
Records cluster at Shawnee National Forest, Midewin National Tallgrass Prairie, and the Upper Mississippi River refuge lands, three very different pieces of the state that share the same thing this rodent actually needs: damp ground with thick sedge or grass cover, not a bog specifically despite the name.
Illinois’s rank of S4, Apparently Secure, sits comfortably above several other small mammals in this batch. Records show up in only 9 of 12 months, peaking sharply in December, but that’s more about when people search than about the lemming vanishing for a third of the year; it doesn’t hibernate and stays active under snow and thick cover through winter.
Full species profile
