Relocation project aims to give fishers a boost in North Idaho

Fishers aren’t easy to find.

They’re sneaky, secretive and there just aren’t that many of them. They live in old growth forests, den in tree cavities and maintain large home ranges with low population densities. A male fisher’s home range might cover between 35 and 40 square miles. No other male would be found inside that range, and there might only be one or two females and a few juveniles.

Trying to catch one in a live trap takes persistence. The trap has to be checked every day. Most days, it will be empty. Joel Sauder, an Idaho Department of Fish and Game biologist who has worked with the species for more than 20 years, said it can take as many as 50 to 100 trap nights to catch a single fisher. Sometimes even more.

“It’s just a low odds game,” Sauder said. “Even in great fisher habitat.”

With enough traps in enough places, though, the odds tilt slightly in your favor.

This fall, Sauder worked with the Idaho Trappers Association to get live traps out across central Idaho. Over the course of about six weeks in November and December, they caught a total of 11 fishers.

The small carnivores then spent a short time at a holding facility near Orofino before being trucked north to the Coeur d’Alene Mountains, where they were released back into the wild.

It was the first year of a relocation project that’s meant to increase fisher numbers in the Coeur d’Alenes, a range that sits between more robust populations to the north and south.

Fishers exist in the Coeur d’Alenes, Sauder said, but because the population is small and isolated, the range is considered a gap in the species’ distribution. To fill the gap, Fish and Game plans to move a total of about 30 fishers over three winters.

Doing so helps not only fishers in that mountain range, but the populations in the Cabinets and in the mountains south of Interstate 90. Having more of the small mammals in between them could help connect those populations, and interbreeding could boost genetic diversity for a species that was once on the brink of extinction.

“Populations are always more robust when there’s good gene flow,” Sauder said.

Fishers have thick, brown fur. They grow to more than 3 feet long and more than 10 pounds, making them the mid-sized member of their carnivorous family – bigger than a marten, smaller than a wolverine. Sauder describes them as “a cross between a wiener dog and a house cat.”

Native to the forests of North America, they were once widespread from the Northern Rockies to the Pacific Coast. Fires and logging in the early 1900s decimated their habitat, and overtrapping all but eliminated them from the western portion of the Lower 48.

They are believed to have been wiped out in Washington by the mid-1900s. Around the same time, Sauder said, people realized they hadn’t seen one in Idaho in a while, which prompted the state to end its fisher trapping seasons.

“We thought fishers had been extirpated from Idaho and Montana at that time,” he said.

A study of a specific genetic signature from a fisher found in the early 2000s eventually showed that the species was never technically extirpated from Montana or Idaho. Even so, they never existed in any significant numbers, and their absence was obvious enough to convince wildlife managers to begin reintroducing them.

In the 1960s, Idaho wildlife officials brought fishers to the Bitterroot and Clearwater mountains of north central Idaho from British Columbia, where populations remained strong. In Montana, fishers from the Midwest were relocated to the Cabinet Mountains in the 1990s. Both efforts worked well, resulting in populations that grew and expanded.

Fishers have been reported elsewhere in North Idaho. This winter, the Kalispel Tribe’s natural resources department started a study in the Selkirks between Priest Lake and the Pend Oreille River with hair snags and track surveys to see if they could find any. Bart George, a biologist for the tribe, said they saw tracks from one this winter.

They have been seen sporadically in the Coeur d’Alenes. An Idaho Fish and Game map of fisher sightings from 1960 to 2022 shows a handful of sightings. Sauder said hair snagging projects have also confirmed their presence.

He said adding fishers to the range is a way to “jump-start what is a low density population.”

The project had been in the works for years. Last fall, the time was finally here. Idaho Fish and Game provided live traps and transport boxes to trappers, and they hit the woods in November.

When they found a fisher in their trap, they’d get word to Fish and Game, which would send someone to pick the animal up and bring it to the holding facility in Orofino.

Sauder said the fishers stayed there until they had a group of them to move at once. Moving them as a group makes them more likely to stay where they’re released.

All of the 11 relocated fishers – seven males, four females – were fitted with GPS collars that provide real-time location data, allowing Sauder to keep an eye on them.

He said a couple of them were caught in traps and died. One went south, crossing Interstate 90. Another headed for Montana.

The rest, however, are doing exactly what he wants.

“Most of them are sticking in the Coeur d’Alenes,” Sauder said.

This summer, the collars will fall off. At that point, Fish and Game staffers can go pick them up and download all the data they’ve gathered over seven months. It will give them a picture of the types of habitats the animals use.

Then, next November, trappers will be back to checking live traps every day, looking for the next batch of transplants.

“The more you can move, the better,” Sauder said.