In Massachusetts, fishers (Pekania pennanti) are one of the largest members of the weasel family. Only otters are larger. Although they are called fishers and fisher cats, these mammals do not fish, and they are not cats. (The term probably comes from early European settlers who thought the animal resembled the European polecat, which they called the fichet or fitche.) They are fierce hunters, however – one of the few creatures that hunt porcupines. Fishers have been spotted in the past near Fresh Pond, and are most active now because March and April is their breeding season.

Full story here.