BAT HIBERNACULA ON LAKE SUPERIORS NORTH SHORE, MINNESOTA

In January 1990, 308 individual bats of four species (Myotis lucifugus , M. septentrionalis, Eptesicus fuscus, Pipistrellus subflavus) were f ound hibernating in two caves along Lake Superior's North Shore in Min nesota. These are the first known natural hibernacula in northern Minn esota, and this is a northerly range extension for P. subflavus. Local rock structure suggests the possibility of a significantly larger ove rwintering population than observed to date.