New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Fisher

The fisher is a North American marten, a medium sized mustelid. The fisher is agile in trees and has a slender body that allows it to pursue prey into hollow trees or burrows in the ground. Despite its name, this animal seldom eats fish; the name may originate from the French word fichet, which referred to the pelt of a European polecat.

The fisher is found from the Sierra Nevada in California to the Appalachians in West Virginia and north to New England (where it is often called a fisher cat), as well as in southern Alaska and across most of Canada. Fishers are present in low density in the Rocky Mountains, where most populations are the result of reintroductions. There is recent evidence, however, that a Montana population persisted in a refugium despite extensive fur trapping in the area during the 1800s and 1900s. Fishers are most often found in coniferous or mixed forests with high, continuous canopy cover.

Adults weigh between 2 and 7 kg (12-25 lbs) and are between 65 and 125 cm (27-49 inches) in length. Males are about twice the size of females, with the smallest females having been recorded being as small as 1.4 kg (3.1 lbs), hardly larger than most other martens, and males at as much as 9 kg (20 lbs). Their coats are darkish brown, with a black tail and legs; some individuals have a cream-colored patch on the chest. All four feet have five toes with retractable claws.

Because they can rotate their hind paws 180 degrees, they can grasp limbs and climb down trees head first. A circular patch of hair on the central pad of their hind paws marks plantar glands that give off a distinctive odor, which is believed to be used for communication during reproduction.

Fishers are also known for one of their calls, which is often said to sound like a child screaming, and can be mistaken for someone in dire need of help.

Hunting and diet

Fishers are solitary hunters. Their primary prey include hares, rabbits, squirrels, mice, shrews, and porcupines. While fishers and mountain lions are the only regular predators of porcupines, the fisher is the only predator to have a specialized a killing technique. By repeatedly biting and scratching at the porcupine's face, they cause it to bleed to death. Because most of the porcupine is covered in quills, the fisher then eats the porcupine by flipping the dead animal over.

Fishers are also known to eat ground nesting birds such as grouse and turkeys. Often, young of the year and eggs make easy targets. Also, in some areas fishers can become pests to farmers because they will get into a pen and kill large numbers of chickens. Fishers have also been known to eat small pets left outside, such as stray cats and dogs. While this is rare, when densities are high and food resources are low, animals may become desperate.

Related Stories
 


Plants & Animals News

November 25, 2025

Researchers studying Yellowstone’s depths discovered that small earthquakes can recharge underground microbial life. The quakes exposed new rock and fluids, creating bursts of chemical energy that microbes can use. Both the water chemistry and the ...
Ribosomes don’t just make proteins—they can sense when something’s wrong. When they collide, they send out stress signals that activate a molecule called ZAK. Researchers uncovered how ZAK recognizes these collisions and turns them into ...
Sargassum seaweed is creating major new obstacles for sea turtle hatchlings, drastically slowing their crawl to the ocean and increasing their risk from predators and heat. Despite the physical challenge, their energy stores stay stable, suggesting ...
UC Davis researchers engineered wheat that encourages soil bacteria to convert atmospheric nitrogen into plant-usable fertilizer. By boosting a natural compound in the plant, the wheat triggers bacteria to form biofilms that enable nitrogen ...
Scientists have created a live-cell DNA sensor that reveals how damage appears and disappears inside living cells, capturing the entire repair sequence as it unfolds. Instead of freezing cells at different points, researchers can now watch damage ...
Migratory birds that fill North American forests with spring songs depend on Central America’s Five Great Forests far more than most people realize. New research shows these tropical strongholds shelter enormous shares of species like Wood ...
Scientists used CRISPR to boost the efficiency and digestibility of a fungus already known for its meatlike qualities. The modified strain grows protein far more quickly and with much less sugar while producing substantially fewer emissions. It also ...
Scientists confirmed that West Coast transient killer whales actually form two separate groups split between inner and outer coastal habitats. Inner-coast whales hunt smaller prey in shallow, maze-like waterways, while outer-coast orcas pursue large ...
Researchers have recreated a miniature human bone marrow system that mirrors the real structure found inside our bones. The model includes the full mix of cells and signals needed for blood production and even maintains this process for weeks. It ...
Massive Sargassum blooms sweeping across the Caribbean and Atlantic are fueled by a powerful nutrient partnership: phosphorus pulled to the surface by equatorial upwelling and nitrogen supplied by cyanobacteria living directly on the drifting algae. ...
During years of scarce fish, African penguins crowd into the same areas as commercial fishing vessels, heightening competition for dwindling prey. A new metric called “overlap intensity” shows how many penguins are affected and is already ...
Scientists are turning venom, radioisotopes, engineered proteins, and AI into powerful new tools against cancer. From Amazonian scorpions yielding molecules that kill breast cancer cells as effectively as chemotherapy, to improved fibrin sealants ...

Latest Headlines

updated 12:56 pm ET