Fisher (Martes pennanti)
The fisher is possibly the swiftest and most agile member of the weasel family. These elusive creatures are primarily nocturnal but may be spotted during the day. Fishers are agile tree climbing carnivores and are one of the main predators to porcupines.
Why they Matter to Us
- Are elusive creatures who peak our curiosity and are an extra special treat to spot in the wild.
- Are a vital part of Alberta ecosystems – they help maintain biodiversity which helps stabilize the ecosystem.
- Are one of the few species that prey on porcupines.
- Their population was in serious decline due to pelt hunting until the 1940's. Their status is unknown today as they are rare in occurrence.
How You Can Help
- Donate to help EALT protect important fisher habitat.
- A fisher has been observed at our Glory Hills natural area. Fishers likely reside at many of our other conserved lands which protect excellent habitat for them and their prey.
- Volunteer to help EALT steward our natural areas and secure more areas to protect.
How to Identify
The fisher has a medium to dark brown coat, sometimes with a cream chest patch of variable size and shape. They have a long body with short legs, a long, bushy tail and large ears. Fishers are 90 - 125 cm in length and the male is larger than the female.
Where to Find
Fishers live in the forests of the boreal and Rocky Mountain natural regions. They are quite secretive and difficult to spot in their natural habitat. They rest in hollow logs, stumps, holes in the ground, and branch nests. In the winter, they use snow dens which have narrow tunnels leading to their burrow under the snow.
Although they are agile climbers, they generally travel on the forest floor.
Our wildlife camera caught a glimpse of a fisher at Glory Hills.
- The fisher is a solitary animal that has an average home range of 25 square km.
- Males generally have larger home ranges which overlap with female ranges but not usually overlapping with other males.
- Fishers can hunt for themselves at just 4 months old, and generally disperse from their home a month thereafter.
- This carnivore is a predator to many: porcupines, lynx, fox, fawns, squirrels, snowshoe hares, rodents, small birds, and many more. They also feed on carrion.
- Young fishers are prey to hawks, foxes, lynx, and bobcats. Adults have almost no natural predators, but they compete for resources against other carnivores.
- Fishers are also known as Fisher cat, or Pennant’s cat, but it is not a cat, nor does it fish! Chipewyan First Nations have a much more accurate name for it Tha-cho, or big marten.
- Fishers can live up to 10 years in the wild.
- Alberta is home to the smallest and largest members of the weasel family. The least weasel is the smallest at 2.5 ounces and the wolverine is the largest weighing 35 pounds.
- Fishers have delayed implantation, meaning the embryo begins to develop but then stops growing and stays suspended until late winter, when it implants and development continues. This also occurs in Alberta bears.