Background Information About the Fisher
Their Home (Habitat)
The fisher is a forest animal and lives all across northern and central North America, as far north as the Yukon border in BC. They do not occur on any of the coastal islands, including Vancouver Island. Streams and rivers support important food (prey species) to fisher. Fisher are reluctant to cross wide open spaces and prefer forests with closed overhead cover.
Fisher use dens - two types, 1) for resting and sleeping and 2) natal dens where the female raises her kits.
Resting dens - may be in the snow, hollow logs, under logs, holes in the ground, witches brooms in trees, squirrel nests, and raptor nests!
Natal dens - occur in cavities of large dead trees located 7-12 m above ground. These tree cavities keep kits warm, provide protection from adult male fishers and provide security from predators. A female may leave her kits unattended for long periods while she hunts.
Snow cover - The fisher's younger cousin the marten, may sometimes compete for the same foods and habitats. However, fisher are not found at high elevations, marten are. Because they are smaller in size, marten are able to hunt under snow during winter. Fisher have to work a lot harder to hunt and travel when snow is deep and soft. Fishers, when they travel in deep snow, use 54% more energy per day than on hard snow. This may be why there are few fishers in coastal BC where deep, wet snow is more common.
Food - fisher eat many kinds of food - snowshoe hare, carrion (deer, moose, . . .), squirrels, porcupine, voles, mice, shrews, moles, muskrats, beavers, birds (especially grouse and jays), snakes, fish, eggs, vegetation, nuts, apples, and mushrooms. Fisher are the primary predator of porcupine.
Behaviour - Fishers hunt their prey by changing direction quickly and frequently, moving in zig zags. When hunting porcupine, they use a different method. Using their speed, they repeatedly attack the face of the porcupine, something that no other animal does. Fisher have been transplanted into areas by forest companies to control porcupine, because porcupine can cause considerable damage to trees.
Populations - Fishers are abundant in eastern provinces and states, but were upgraded in BC from the Blue to the Red List in 2003 to the end of 2004. At this time it is on BC's Blue listed, since recent studies have shown there is more existing habitat than originally thought.
Habitat Management - Fisher depend on old growth forests, with large old trees and younger trees in the under story, lots of downed logs, snags and a closed canopy. When habitat disappear, so do fisher. By limiting the size of clearcuts, by cutting blocks in irregular shapes to increase the amount of edge, by not cutting trees in drainage bottoms and along ridgelines, fisher can survive better. For den sites if snags are preserved and mature and old stands, fisher will benefit. They may not colonize if natal dens are not available.
Enhancement - Refuges - where no logging or trapping takes place - insure against population reductions. A fisher population needs a 250km square area, and this type would also be important for other species such as the marten, wolverine, and lynx populations.
In the Cariboo/Chilcotin Region in 1996-1998 a three year transplant program moved fisher from their homes in the Cariboo/Chilcotin to the East Kootenay where they were extirpated. Fisher populations are much better in some areas of our region than in other regions within the province, allowing us to transplant and still maintain a healthy fisher population.
