The Return of the Fisher

Fishers are back. No, not fishermen - the weasels that disappeared in Washington state after heavy fur-trapping in the 1800-1900's. Wildlife biologists started bringing them back to the Olympic Peninsula in 2008 (from Canada) and in 2016, to the Cascades. You may be lucky enough to see one in the wilderness this summer.
Placeholder Contact Profile Joan Miller
Snowshoeing and Climbing Grad
May 16, 2017
The Return of the Fisher
By Joan Miller

With their luxurious dark brown coats, fishers were irresistible to trappers in the 1800’s and early 1900’s. Their pelts brought a good price. By the late 20th century, none of these large members of the weasel family could be found in Washington State. Trapping and loss of their forest habitat led to their disappearance. In 1998, although fishers still could be found in neighboring states and other regions, Washington declared fishers endangered.

With surveys turning up zero fishers, state biologists began laying the foundation for a recovery plan. But it was 10 years before fishers were again walking on Washington soil. 

Fishers are mesocarnivores, mid-sized animals that eat mostly meat but also fruits, fungi and plants, and help maintain balance in an ecosystem. They have short rounded ears, long bodies, short legs and long bushy tails. Males weigh 8-12 pounds and range from 35-47 inches from nose to tail, while females weigh 4-7 pounds and range from 30-37 inches long. Patti Hape, chief of the Wildlife Branch at Olympic National Park, says they can live up to 10 years. There is wide variation in fisher genetics throughout North America, and based on historic genetic material from Washington State, biologists determined that fishers from central British Columbia are the closest match to the animals that once roamed our forests, Patti explains.

In 2008, wildlife biologists began an ambitious project to bring fishers back. Over a three-year period, they relocated 90 fishers from Canada to the Olympic Peninsula. But despite their name, fishers do not frequent waterways nor do they eat fish. Happe says the release sites were carefully selected based on criteria that satisfied fishers’ needs. 

“We thought unforested ridges and rivers would be a barrier to their movements,” says Patti. “But no. The males that were released went far, but they came back in breeding season.” Females also moved around some, but stuck closer to their home ranges. Females are more vulnerable, Happe adds, because they are smaller than males and rely on tree cavities for denning.

Biologists tracked the first relocated animals with radio collars and were amazed at the distances the fishers traveled. Though the collars have stopped working, tracking continues with cameras and hair snares. The genetic analysts, using material from the hair snares have been able to identify young of the original animals, so they know the population is finding success.

Fishers prefer forests with dense canopy cover. Their diet includes a variety of small mammals, including snowshoe hares, but they are known as the only predator of porcupines. A surprise to biologists at Olympic National Park was the discovery that fishers prey on mountain beavers.

The greatest threats to fishers, says Patti, are predators, especially bobcats and mountain lions, and roads. Fishers have been killed trying to cross roads.

The guarded success of fisher recovery on the Olympic Peninsula has encouraged biologists to expand the effort to the Cascades. Later this year, if all goes well, state and national park officials will begin releasing the first of 160 planned fishers in the Cascades. The first phase of the Cascade plan targets the southwestern Cascades, including Mount Rainier National Park. About half will go there, with the rest going to the northwestern Cascades, including North Cascades National Park.

This article originally appeared in our January/February 2015 issue of Mountaineer magazine. To view the original article in magazine form and read more stories from our publication, click here.

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