Northern myotis is a bat in genuine trouble, in Illinois and everywhere else. NatureServe ranks it S1, Critically Imperiled, in Illinois, and G2, Imperiled, across its entire range, a sign this isn’t a species merely scarce at the edge of its territory. A fungal disease called white-nose syndrome has cut hibernating bat colonies by the tens of thousands across the eastern United States, and this species has been hit especially hard.
Only 16 Illinois records exist so far, gathered from Emiquon and the Illinois River wetlands, central Illinois state parks, and wooded stream corridors, the kind of forested, insect-rich habitat this bat hunts through at night. It roosts under loose tree bark in summer and needs cool, humid caves or mines to survive winter, so both halves of its year depend on habitat that’s getting harder to find intact.
February and March carry the most Illinois reports, likely reflecting winter hibernation surveys rather than when the bat is most active outdoors. With a record this thin, a missing month doesn’t tell you much; it’s the disease trend and the S1 rank that tell the real story here.
Full species profile
