Fishers flourish in former forest home

Fishers in the northern Sierra Nevada, den and rest in cavities found in large, older trees. Members of the weasel family, fishers are adept climbers as they hunt their preferred prey, gray squirrels. In 2004, fishers in California, Oregon and Washington were being considered for listing as threatened or endangered. Credit: Aaron Facka/Oregon State University

Long-term collaborative study successfully concludes as fishers thrive on managed forest in northern Sierra.

By Susan Sawyer
February 6, 2018

A sleek, grizzled brown cat-sized fisher is huddled in a wooden box attached to the back of a wire trap in the bottom of a forest drainage. A shiny chicken bone hanging from twine inside is a reminder of how the 2 year-old female was lured inside the night before.

Dr. Aaron Facka of Oregon State University approached the trap quietly as others aimed cameras toward the presumed fisher escape path.

The Stirling fisher translocation project was a successful collaboration between U.S. Fish and Wildife Service, California and Sierra Pacific Industries to return fishers to a portion of their historic range in the northern Sierra Nevada. Credit: Aaron Facka/Oregon State University

Dr. Deana Clifford, senior wildlife veterinarian for the California Department of Fish and Wildlife, swiped a handheld wand over the box, listening for a signal. A beeping indicated the fisher had an implanted microchip from a recent capture. Fisher identity confirmed, Facka pulled the rear panel from the box and gently tapped the top. In a blur of fur, the fisher streaked out, feet flying over leaves and limbs, disappearing deep into the forest in mere seconds.

Dr. Deana Clifford weighs an adult fisher in the mobile lab. Blood, scat, DNA and other samples were taken from each fisher trapped during the project. Credit: Aaron Facka/Oregon State University

For the group, who represented the partners responsible for the nearly decade-long fisher translocation project, the moment symbolized the successful collaboration to return fishers to a portion of their historic range. 

Tina Bartlett, north-central regional manager for the state and Bjorn Erickson, a U.S. Fish and Wildlife Service Recovery Division biologist, commented it was the first time they had seen a fisher in the wild. “They sure don’t hang around long for a photo opportunity,” said Erickson.

Members of the weasel family, fishers (Pekania pennanti) could be described as a mishmash of wolverine, bear, otter and squirrel. Their main prey on this site is gray squirrels, but, as Clifford said, “A fisher will eat anything smaller than a fisher.”

Fishers in western North America once ranged from California’s southern Sierra Nevada north to British Columbia, but over-trapping and loss of habitat reduced fisher populations throughout its range. Even though California prohibited commercial fur trapping of fishers in 1946, their population continued downward.

In 2004, fishers in California, Oregon and Washington were being considered for listing as threatened or endangered. During the review process in 2006, Sierra Pacific Industries offered one of their properties in the northern Sierra Nevada as a potential site to translocate fishers. Working with the state, they determined the 160,000 acre Stirling Management Area east of Chico, Calif. as most suitable for the project.

Fishers in the northern Sierra Nevada use cavities found in large, older trees, and are adept climbers as they hunt their preferred prey, gray squirrels. Credit: Aaron Facka/Oregon State University

Although fishers had been reintroduced to many locations in North America in the last 100 years, this was the first attempt in California to re-establish them in part of their former range. Another primary goal was understanding if and how fishers survived on managed/logged forests in western North America.

“This is one of the fundamental differences between our translocation and all others,” said Facka. “The relationship between science, conservation, and partnerships between agencies, private landowners and academic researchers was a crucial part of the fisher success story.”

The Service worked with Sierra Pacific Industries and the state to develop a Candidate Conservation Agreement with Assurances which supported fisher translocation and better understanding of fishers in managed forests. A more recent agreement provides for large older trees with cavities for fisher denning and resting.

A fisher trap baited with a chicken leg and tucked into a hollow log in the bottom of a forest drainage, where fishers typically travel. Credit: Pam Bierce/USFWS

Laura Finley, Service fisher project lead in the Yreka Fish and Wildlife office, stressed the importance of the collaborative effort. “We've been engaged in this partnership since its inception; fisher translocation/relocation may not have happened without the Stirling agreement with SPI, along with the hundreds of thousands of dollars invested by the Service,” said Finley.

From December 2009 through December 2011, field teams began trapping and moving 40 fishers from existing populations in northern California to the Stirling site.

Dr. Roger Powell, North Carolina State University fisher project field research leader, uses telemetry to locate a collared fisher in the forest. Every fisher during the course of the study was collared to track movement, survival and reproduction. Credit: Aaron Facka/Oregon State University

Dr. Roger Powell, renowned fisher expert from North Carolina State University was hired to lead the research project, along with Facka who was working on his Ph.D. at the same university. Each translocated fisher was microchipped and fitted with a radio-collar to track their movement, survival and reproduction as they established new home ranges within the property.

Funding for a project of this scale was key to its longevity and ensuring quality research. Dan Tomascheski, Sierra Pacific Industries vice president, estimated total costs of the project to be close to $4 million, largely funded by his company.

“We knew we had fisher habitat," said Tomascheski. "SPI wanted this project to succeed, despite the doubts and comments from the outside that fishers would die or the project was doomed to fail.”

“SPI was invested from the beginning, and we knew to trust in and follow the science,” he said.

Since translocation, the fisher population thrived in their new forest, with no apparent adverse effects from logging activity, which included noisy timber harvest equipment and over 20 logging trucks running daily. Round-the-clock monitoring by trail cameras, radio telemetry and trapping showed the fishers were healthy, reproducing and expanding their range onto a nearby national forest and private land.

An adult fisher being anesthetized and processed in the field lab. Blood, scat, DNA and other samples were taken from each fisher trapped during the project. Credit: Aaron Facka/Oregon State University

Although the fisher field project was to end after seven years, researchers felt more data was needed, so Tomascheski secured funding through 2017. Last November, the final push began to trap fishers and remove any remaining collars, providing an opportunity for the cooperating partners to meet the field team, possibly see a fisher and recognize the successful conclusion of this translocation.

This 30-day effort, the ‘final fisher frenzy,’ involved coordinating several teams checking 100 traps daily while dodging weather, locating dispersing juveniles and avoiding black bears stealing chicken legs from traps.

Dr. Deana Clifford explains the mobile lab for processing fishers to a group representing the partners for the translocation study. Credit: Susan Sawyer/USFWS

A total of 61 fishers were trapped, with blood, DNA and scat samples taken from each. Enough valuable data was collected over the entire project that Facka expects to be writing professional journal papers on fisher-related topics over the next several years.

Whether it was fate or not, on the last day of the ‘frenzy’, Facka captured the only surviving fisher from the original 40 translocated, a male first released as a juvenile in December 2011. As the fisher was released, researchers felt the project had come full circle.

“When we started the field project, none of us had met or worked together before. We took an eight-year journey together to advance the science and conservation of fishers, and became a second family along the way,” said Clifford. “This project demonstrates collaborative conservation can work.”

A fisher peers from a trap box, where it was lured in by a chicken leg the night before. During the last month of the Stirling study, 61 fishers were trapped one last time to remove radio collars and collect final data. Credit: Aaron Facka/Oregon State University

Representatives from the partners involved in the long-term fisher study met with field team members for a day in the forest last November. From left: Dr. Aaron Facka; Dan Tomascheski, Sierra Pacific Industries vice-president resources; Dr. Deana Clifford, senior wildlife veterinarian, California Department of Fish and Wildlife; Tina Bartlett, California Department of Fish and Wildlife north-central regional manager; and Bjorn Erickson, recovery division biologist, U.S. Fish and Wildlife Service. Credit: Susan Sawyer/USFWS

 

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Susan Sawyer

About the writer...

Susan Sawyer is the Klamath Basin public affairs officer covering Yreka, Klamath Falls and the Klamath Basin refuges. She grew up with a family who instilled a deep appreciation of the outdoors.

When finished unpacking a multitude of boxes from her move to a new home, she will return to her off-duty interests: bird hunting, traveling, classic rock and blues, and spoiling her animals.