The fisher is a mammal found across North America, often misunderstood due to its misleading name. Despite common misconceptions, it is not a fish or a feline. This elusive forest dweller is a unique and adaptable predator.
Understanding the Fisher
The fisher (Pekania pennanti) is a carnivorous mammal in the Mustelidae family, which includes weasels, martens, and otters. Recent DNA analysis reclassified it into its own genus, Pekania, due to its distinct evolutionary relationship with wolverines.
Fishers have a long, slender body, short legs, and a bushy tail. Males are larger than females, typically measuring 90–120 cm (35–47 inches) in length and weighing 3.5–6.0 kg (8–13 pounds). Females are 75–95 cm (30–37 inches) long and weigh 2.0–2.5 kg (4–6 pounds). Their fur is dense and glossy, ranging from dark brown to black, often with a grizzled or silver sheen on the head and shoulders. Some individuals display irregular white or cream-colored patches on their chest or groin.
Where Fishers Live and How They Behave
Fishers are native to North America, inhabiting forested and semi-forested landscapes. Their distribution spans much of the boreal forest in Canada and extends into the northern United States, including New England, the Great Lakes states, the northern Rockies, and some West Coast regions like Oregon and California. They prefer dense, mature forests, especially coniferous and mixed woodlands.
These animals are solitary, interacting mainly during mating season. They remain active year-round and do not hibernate. While active during the day, fishers are often crepuscular, most active at dawn and dusk, though nocturnal activity is also common. Fishers are agile climbers, capable of rotating their hind feet almost 180 degrees to descend trees headfirst. They spend most of their time foraging and hunting on the forest floor, using hollow logs, tree cavities, and rock crevices for resting and denning.
What Fishers Eat and How They Hunt
Fishers are carnivores with a diverse diet. Their primary food sources include small mammals like snowshoe hares, mice, voles, and squirrels, as well as birds and their eggs. They also supplement their diet with carrion, fruits, and berries.
Fishers are one of the few animals that regularly hunt porcupines. They employ a specific strategy, repeatedly attacking the porcupine’s unprotected face. They circle the porcupine, darting in to bite its face while avoiding its defensive quills, gradually exhausting their prey. Once subdued, the fisher begins consuming it from the unprotected belly or head and neck area. While not immune to quills, fishers appear to tolerate or quickly recover from injuries that would be more severe for other predators.
Fisher Conservation Status
The fisher’s global conservation status is “Least Concern” by the IUCN. However, this status varies regionally, with some populations listed as federally endangered or threatened. Historically, overtrapping for fur in the 18th and 19th centuries led to widespread declines and extirpation from many areas. Habitat alteration, including extensive logging and agricultural development, also contributed to their reduction.
Today, fishers face ongoing challenges, including habitat loss and fragmentation due to logging, development, and forest fires. Other threats include vehicle collisions, disease, and poisoning from rodenticides. Despite these challenges, conservation efforts like protection measures, habitat recovery, and reintroduction programs have allowed fisher populations to rebound in many parts of their historical range. Ongoing research and regulated harvest programs also contribute to sustainable management.