Fisher - Photo Copyright Ward Cameron 2003 - Click to view a larger image Fisher - Photo Copyright Ward Cameron 2003 - Click to view a larger image Fisher - Photo Copyright Ward Cameron 2003 - Click to view a larger image Fisher - Photo Copyright Ward Cameron 2003 - Click to view a larger image 
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Martes pennanti

Weasels, Skunks & Allies (Mustelidae)

Measurement: Size: 90-120 cm Weight: 3.5-5.5 kg

Description: This large weasels is a powerful predator. They are about the size of a fox, with a dark coat. There may be light patches on the chest or belly. They are excellent climbers, and like the marten, can descend a tree head first. Despite their climbing prowess, they do much of their hunting on the ground. Fishers also have a larger head and stalkier appearance than other weasels.

Range: They are found through most of the Canadian provinces south of the territories, and in certain pockets in the United States. In particular, their range extends throughout the Canadian and American Rockies. Their primary habitat is old growth coniferous forests near streams and rivers.

Fishers are larger than martens, and so lose heat less readily. Their larger size restricts their ability to follow the marten into hiding places beneath the surface, but at the same time, their larger body makes it more difficult to stay on top of the snow. To compensate, fishers take advantage of lower elevation valleys where the snow accumulation may not be as deep.

Logging represents one of their biggest challenges as it removes the complex forest floor upon which fisher and martens depend.

Diet: Fishers are vicious hunters, and while snowshoe hares are their primary prey, they are one of the few animals able to effectively hunt porcupines. They circle their prickly prey, repeatedly biting and clawing them on the face until (after a half an hour or more) the porcupine collapses. The fisher finally flips the porcupine onto its back to access its soft (and spine free) belly. Fishers also take almost anything else it can catch including grouse and other birds, squirrels, fish, snakes, carrion, and even some plants and berries. Fishers are also excellent swimmers, and may feed on the occasional mink or muskrat.

Reproduction: It's a typical weasel story. They mate in the spring, with delayed implantation until the following winter. They give birth to a small litter of 1-6 (usually only 2 or 3) in spring.

Male fishers are much larger than females, and will compete with other males for the opportunity to mate. They use secretions from their anal glands to mark their territory and to help exclude other males.

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All Material Ward Cameron 2005



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