More Fishers Come Home to the Olympics


December 14, 2021

By Karen Povey, WNPF Board of Directors

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 brought from Canada to be released this day in the wild southeast corner of Olympic National Park.

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.

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 our state 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. Washington’s National Park Fund has provided long-term support to the recovery effort, thanks to the incredible generosity of our donors.

The Ongoing Journey of Fisher Recovery

The long road toward fisher recovery moved from planning to action in 2008 when animals captured in British Columbia were first released into Olympic National Park. By 2020, 250 fishers brought from Canada had been released into areas of prime fisher habitat on the Olympic Peninsula and in the Cascades with release sites in Olympic, Mount Rainier, and North Cascades National Parks.

A fisher with tracking collar races out of his carrying container
A fisher emerges at Olympic National Park, by Karen Povey

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. And most importantly, these wide-ranging animals must find each other for breeding. Gauging the success of the 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.

Keeping Tabs as Animals Disperse

During a Washington’s National Park Fund virtual field trip in March 2020, Patti Happe, Wildlife Branch Chief at Olympic National Park offered an overview on how the recovery team kept tabs on the original 90 Olympic fishers as they dispersed and established home ranges. When released, fishers were fitted with radio-tracking collars or implanted transmitters which allowed them to be located during flights over the park. The results showed that the animals – especially the males – wandered widely, even venturing far out of the park to some coastal locations in Neah Bay, Ocean Shores, and near Port Angeles.

Map of fisher locations captured through aerial tracking
Fisher locations after the first phase of releases in Olympic National Park in 2011, detected through aerial tracking

The tracking results were mostly encouraging, revealing that many fishers remained alive years after release and most eventually stopped wandering and set up home ranges. Ground crews were able to find several den sights and even use remote cameras to get photos of fishers with young, confirming that reproduction was occurring – a critical measure of the program’s success. However, biologists had some concern that the ranges of males and females didn’t overlap as much as hoped, which might limit the ability of some fishers to find one another for breeding.

To gain a better perspective on what was happening with breeding and to continue to monitor the fishers’ locations after their transmitter batteries died, the monitoring shifted to a ground-based approach in 2013. Crews set over eighty sampling stations throughout the Olympic Peninsula, consisting of a tree-mounted camera, chicken bait to ensure the fisher would move into camera view, and hair snares at the base of the tree.

Fisher sampling station set up in Olympic
Sampling station set-up with a camera, scent lure, bait, and hair snare

By 2016, biologists had gathered enough data to conclude that thirty-five individual fishers were alive and well on the Peninsula. They also assessed DNA gathered from the hair snares to determine the parentage of offspring, discovering both first and second-generation young from the original animals. So that was all really good news!

More Breeding Pairs Needed to Keep the Population Healthy

However, further analysis of the genetic samples indicated that just a handful of female fishers had produced most of the kits, leaving many animals unrepresented as parents. This is concerning because it’s important to have as many individuals as possible in a population be breeding to diversify its genetic makeup. Low genetic diversity leaves a population much less resilient in the face of disease outbreaks or environmental changes. In further study, scientists conducted computer modeling to predict the long-term genetic fitness of the population. This resulted in a recommendation to periodically add more fishers from Canada to introduce new genes.

And that brings us back to the crowd gathered that sunny fall morning. Project biologists have high hopes that the new fishers (along with five others released elsewhere in the park) will breed with existing Olympic animals, providing an infusion of new bloodlines to diversify – and thereby strengthen – the population’s genetic profile. Ideally, fisher populations in the Olympics and Cascades will someday be connected so this genetic swap can take place naturally.

The story of fisher recovery is the story of persistence. We salute the many dedicated people and organizations that have worked tirelessly on this effort for decades. It takes commitment to save endangered wildlife and those of us at Washington’s National Park Fund are grateful to work with a community of wildlife professionals and loyal donors who share this vision.

Cover photo of fisher by Karen Povey.