Little brown bats were once one of the most common bats in Massachusetts, but white-nose syndrome has cut the state’s population by an estimated 90 percent or more since the fungal disease reached New England caves in the late 2000s. Records near Parker River National Wildlife Refuge and Blue Hills Reservation reflect summer foraging territory, not the handful of surviving hibernation sites that now hold the state’s remaining colonies.
Records spike sharply in July, more than ten times the near-zero winter months, tracking the peak of summer maternity-roost activity when females and pups are most visible on the wing. The IUCN now lists the species Endangered globally, and Massachusetts’ own S2, imperiled, rank tells the same story at the state level.
Full species profile
