The fisher king
On the comeback trail with Northern California’s most mysterious weasel
Having a conversation with Roger Powell is sort of like watching Animal Planet. The North Carolina State University professor speaks in a deliberate, almost hushed voice as he describes the fisher, a slender, weasel-like mammal whose name probably won’t ring a bell with most people. To call him an expert might be an understatement.
Powell—who sports a gray billy-goat beard—has been studying the fisher for more than 30 years, though his interest in the animal dates back even further.
“From the time I was a kid, I was fascinated by weasels,” he explained. “Mostly from what I read in books.”
It’s no wonder Powell is taking part in a new project to examine and reintroduce the fisher to Butte County. The animal vanished from the region in the 1920s.
Over the past month, four female fishers have been released into the wild just outside Stirling City, 104 miles north of Sacramento. Researchers and biologists from the California Department of Fish and Game and the U.S. Fish and Wildlife Service will release 40 of the creatures over the next three years in hopes of rebuilding the population in the area and learning more about these speedy, rarely seen animals.
“We don’t anticipate failure,” said Powell, who receives the animals’ coordinates in North Carolina via radio collars and surgically implanted transmitters. “But if we don’t document it, we can’t learn from it.”
The fisher is a quick and slender predator that, when seen, is often mistaken for a wolverine or even a small bear cub. Despite its name, the animals rarely eat fish, mostly feeding on small rodents, rabbits, and even birds and snakes. They’re voracious eaters, too. A full-grown 5-pound female can eat a rabbit a little less than half its weight, a meal that can last the creature several days.
“It’s kind of like feast or famine,” explained Powell. “It’s like Thanksgiving again and again and again.”
Male fishers weigh as much as 10 pounds and are extremely strong. The creatures are among the few predators that can kill a porcupine, because their bodies are skinny and low to the ground, enabling them to overcome the prickly critter by biting it repeatedly in the face. The process can take up to a half-hour.
Perhaps it’s all the moving around that gives the animals such an appetite. Fishers will travel great distances—up to 60 miles in rare cases—before finally settling on a home range, where they will hunt, mate and make their homes inside of old, hollow trees.
It was the devastation of forests in the late 19th century that caused severe decline in fisher populations. Fisher pelts were also sought after in the late 1800s and early 1900s, fetching more than $100 each.
The population hit an all-time low in the United States in the 1930s. It wasn’t long before states began to offer protection to the animals (Powell notes that protection wasn’t offered in California until the ’40s). While it’s considered a “candidate species” and has been warranted certain protections, the fisher has never officially been placed on the endangered-species list.
Populations these days are nowhere near their historic levels, but the animal’s future is looking better.
The seven-year, $380,000 study—funded by the DFG and FWS—is one of several in the country working to rebuild fisher populations. A similar reintroduction project was initiated two years ago in Washington, a state that lost its entire population to trapping by the early 1900s.
Richard Callas, a senior environmental scientist with the DFG, has been in the field over the past few weeks working closely with the translocation of the fishers, trapping the animals in the wooded areas on the 160,000 acres in Shasta, Trinity and Siskiyou counties owned by Sierra Pacific Industries. Callas says the females released in Butte County are all doing well so far. By the end of the winter, nine females and six males will have been returned to the area, and there are plans to release an additional 15 by the end of the year.
Because fishers generally are solitary mammals and are prone to cover a lot of terrain, scientists are taking several measures in order to keep tabs on the critters. Small transmitters are surgically implanted in the females’ abdomens, while the larger male fishers will be fitted with radio collars. Using hair samples—taken from adhesives set at bait stations—scientists also will be able to use DNA to find out the parents of newborn fisher kittens.
Aaron Facka, a North Carolina State University grad student working under Powell, is the “hands-on guy” heading out in the field almost daily. It’s not surprising that he’s developed a new appreciation for an animal that to this day remains a relative mystery.
“The kinds of things you see them do are pretty awe-inspiring,” Facka said. “My hopes are they’ll do well and that there will be a [fisher] population in the Sierras long into the future. And we hope to learn a little something about these guys.”