Critter of the Month: Fisher
Among a cathedral of towering cedars, shafts of rare November sunlight spilled through the sagging limbs, illuminating the misting moss and ferns. The stunning setting seemed to lend an apt air of reverence for the fifty-or-so folks gathered to witness the latest phase in a long-unfolding conservation story: the repatriation of once-extinct fishers to Washington’s forests. The group was waiting expectantly for a new group of fishers (Pekania pennanti) brought from Canada to be released this day in the wild southeast corner of Olympic National Park.
Carrying an about-to-be-released fisher after its journey from British Columbia
The expectant crowd gathered for the release
The guests of honor were likely experiencing a very different sense of anticipation. The five fishers had been captured over the preceding two weeks in Alberta and were cared for temporarily at the Calgary Zoo. Their long journey was now culminating as their travel boxes were carried to the edge of the forest. One by one, the box doors were lifted and dark eyes cautiously peered out. While one hesitant animal needed some coaxing to emerge, the others sprang out quickly, ditching the security of the crate as they disappeared into the forest in moments.
Fisher takes a peek out of the box….
…and is gone in a flash!
The Ongoing Journey of Fisher Recovery
As they launched their slender bodies rocket-like into the unknown of their new homes, the fishers had no idea of the weight of expectation riding on their furry shoulders. These cat-sized members of the weasel family disappeared in Washington by the 1930s due to loss of habitat and over-hunting for their luxurious fur. An intensive effort by biologists with the National Park Service, Washington Department of Fish and Wildlife, and many nonprofit and tribal partners over the last two decades has made significant progress in bringing fishers home.
Between 2008 and 2020, 250 fishers captured from more robust populations in British Columbia had been brought to Washington State and released into areas of prime fisher habitat in Olympic, Mount Rainier, and North Cascades National Parks.
A fisher at Northwest Trek Wildlife Park
Keeping Tabs as Fishers Disperse
Gauging the success of the fisher recovery program requires intensive monitoring of the whereabouts and reproductive activity of the fishers, a difficult task given the challenging terrain and large distances involved in searching for such small and secretive animals. Prior to release, fishers were implanted with transmitters to allow biologists to track their movements. Because the fishers roam in remote, mountainous areas, the only way to detect their signals is by taking to the air in small planes fitted with antennas.
Each individual transmits at a different frequency so they can be identified as the receiver picks up their location pings and their locations noted on a map. Of most interest to the biologists are the females. When their location points begin to concentrate, it’s likely they’ve created a den site. Ground crews sent in have found several dens and even used remote cameras to get photos of fishers with young, confirming that reproduction was occurring – a critical measure of the program’s success.
Tracking fishers above Mount St. Helens
Searching for a tiny fisher within hundreds of miles of forest
High above the fishers of Mount Rainier National Park
The Future of the Fisher
After the tracking devices run out of battery power, monitoring fishers becomes solely ground-based using cameras and collecting hair swabs and scat for genetic analysis. The lab tests will tell biologists if enough animals are breeding to maintain the genetic diversity so important for keeping the population healthy. When a population’s numbers are so low, this is a very real threat to their survival and will be closely monitored as recovery continues. Tests so far have documented both first and second-generation young from the original animals - an early sign of success!
While the release of these animals is indeed cause for celebration, it really represents just the beginning of the establishment of a population that can persist into the future. Released fishers may encounter many hazards as they venture into their new homes, including predation by larger carnivores and being struck by vehicles. It will be many years before biologists will know if their decades of effort have been successful in saving this once-extinct, now endangered mammal in Washington.
The story of fisher recovery is the story of persistence. Many dedicated people and organizations have worked tirelessly on this effort for decades. Through my work with Northwest Trek Wildlife Park and Washington’s National Park Fund, I’m grateful to work with a community of wildlife professionals and donors who share this vision.
Northwest Trek Wildlife Park fisher
Fisher Likes: Munching on rabbits, squirrels and even porcupines. They are one of the few predators of porcupines, having a talent for biting at the rodent’s soft belly while dodging the stabbing quills.
Fisher Dislikes: Having a misleading name. Fishers don’t eat fish. Their name is thought to come from the Dutch or French word for the European polecat, or “fitch.”
Fisher Super Power: Finding each other over long distances and tough terrain! With only a small number of fishers roaming large expanses of forests and mountains, it’s incredible males and females can find one another for breeding.
Wonder how you can help fishers?
You can find tons of resources here about Washington Department of Fish and Wildlife’s fisher recovery efforts.
You can support monitoring of fisher populations by donating to Washington’s National Park Fund priority science projects.