Fishers are large members of the weasel family and one of the few predators known to regularly kill porcupines, flipping them onto their backs to reach the unprotected belly. Blue Hills Reservation’s wooded reservations near Boston mark the eastern edge of a range that expanded back across Massachusetts as forests regrew over the past century, following the same trajectory as the state’s returning bobcats.
Records peak from December through February, more than three times the summer low, a pattern that likely tracks winter breeding activity and easier tracking in snow rather than any true seasonal shift in fisher numbers. The species hasn’t yet been formally evaluated by the IUCN globally, even though Massachusetts’ own NatureServe rank of S4, apparently secure, suggests a stable population here.
Full species profile
