Wildlife

Fishers of the Pacific Northwest

These elusive, forest-dwelling animals are agile and swift climbers. Fishers look similar to their relatives, the weasels and Pacific martens, but are much larger in size and have a darker coat. These carnivores are roughly the size of a house cat and weigh 4.4-13 pounds. They’re 3-3.5 feet long, including their long furry tail that’s often 14-15 inches in length. Some have even described fishers as ‘chunky weasels’ or ‘tree wolverine’ because of their size and tree-climbing abilities.

Found in forests and near rivers, fishers thrive in complex and diverse forest structures, particularly old-growth forests, and will create dens out of cavities in live or dead standing trees. These animals are solitary carnivores that rely on a diet on a variety of food. They’ve been known to eat birds, rabbits, fish, small mammals, nuts, seeds, and berries. They’re also one of the only species that can kill a porcupine, which is actually one of their favorite things to eat. (Although, the fight between a fisher and porcupine isn’t particularly pretty or fast.)

Other than mating and raising their litter, fishers live alone in several square miles of their own territory that can overlap with other fishers. Like otters, this species has a short gestation period but delayed implantation means it can take almost a year for a litter to be born. Baby fishers, called kits, are usually born in the spring and remain with their mother until they’re roughly 5 months old.

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Restoration and Reintroduction in Washington State

Historically, fishers were common from Northern California to British Columbia but were over-trapped to extinction for their fur. In 2002, organizations like Conservation Northwest partnered with the Washington Department of Fish and Wildlife, National Park Service, and other federal and tribal agencies to reintroduce the species back to their natural habitats in the Olympic Peninsula and Washington’s Cascades. This partnership helped bring fishers back to the state and since 2008, more than 250 fishers have been released in different parts.

While there has been some success in reintroducing fishers to the Pacific Northwest (particularly in western Washington), the Trump administration denied protection under the Endangered Species Act to most of the species in May 2020. Only two naturally occurring populations remain. There are 100-500 in the southern part of California’s Sierra Nevada mountain range and an estimated 3,000 in northern California and southern Oregon, a sharp decline from the tens of thousands that once roamed most of North America’s west coast.

Logging could be a contributing factor to the decision to not grant protection to the species, as fishers live in habitats that are great for logging purposes. A recent lawsuit in California has even challenged the US Forest Service as a way to stop different logging projects in the Sierra Nevada mountains. But the US isn’t the only government failing the fisher, as British Columbia has also been accused of not doing enough to protect the species.

Current Threats

In addition to not being protected by the Endangered Species Act, fishers face numerous other threats. Logging projects up and down the west coast threaten their habitat and wildfires from the last few years have ravaged their habitat too. Pesticides and rat poison like Anticoagulant rodenticides are now a threat and can damage a fisher’s liver and blood vessels before killing them.

Difference Between Fishers, Weasels, Pacific Martens, and Wolverines

As a part of the Mustelid family, fishers look very similar to their relatives, weasels, Pacific Martens, wolverines, and others. As far as size, wolverines are the largest members of this family at 20-40 pounds and weasels are by far the smallest. Weasels will often weigh less than a pound, making them significantly smaller than most of their relatives. Coat colors also differ between Mustelid species, with weasels generally having light brown or white coats and fishers and wolverines have dark coats.

It can be difficult to see any of these animals out in the wild but it’s not impossible! Like any other wild animal, fishers (and relatives) should be given plenty of space if you do come across them. Fishers tend to avoid developed areas and humans and they’re rather elusive, meaning they’re not particularly dangerous to humans. In other parts of North America, fishers have occasionally preyed on domestic animals like cats, rabbits, and chickens, but predation is rare on the west coast.

Ultimately, fishers are an important part of an ecosystem and a rather interesting species! These solitary and elusive animals can be hard to see out in the wild and can be confused with relatives like Pacific martens and wolverines. But even so, fishers need our help against threats like wildfires, climate change, and often unintentional poisoning.

Have you ever seen a fisher before?

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