Relocated grizzly joins growing population in Cabinet-Yaak Ecosystem

A 2.5-year-old grizzly bear emerges from a culvert trap in the Cabinet Mountains on July 21. (Photo courtesy Montana FWP)

Montana Fish, Wildlife and Parks trapped and relocated a young grizzly bear in the Cabinet Mountains near the Montana-Idaho border, adding the 120-pound male to the small but growing population of grizzlies in the state’s northwest corner.

The bear became the 20th grizzly moved to the Cabinet-Yaak Ecosystem through an augmentation program launched in 1990 to save the population and boost genetic diversity. The last release occurred in 2016.

“We’re trying to increase the genetic structure of the population by bringing in unrelated individuals with no history of conflict,” said Kim Annis, FWP grizzly bear management specialist. “We have a really good family tree for the Cabinet Mountains that shows we might possibly have lost the population altogether without having continued this augmentation program.”

Working in partnership with the U.S. Fish and Wildlife Service, FWP captured the bear near Stryker Basin in the Stillwater State Forest. Biologists fitted the bear with a GPS radio collar for future monitoring.

It was released in a remote area west of Spar Lake in the Kootenai National Forest south of Troy.

Wayne Kasworm, a grizzly bear biologist for the U.S. Fish and Wildlife Service, said the grizzly population in the Cabinet-Yaak nearly vanished 30 years ago.

In 1988, biologists estimated that fewer than 15 grizzly bears remained, even though the Cabinet-Yaak spans 1,000 square miles in the Yaak River drainage and 1,600 square miles in the Cabinet Mountains.

“Knowing what we know now from sampling, I think that was actually a very generous estimate,” said Kasworm. “The number of bears were probably in the single digits.”

Kasworm said as many as 55 grizzly bears now reside in the Cabinet-Yaak Ecosystem. One female bear relocated in 1993 is responsible for at least 25 descendants over three generations. The bear produced 10 first-generation offspring, which gave rise to at least 14 additional grizzly bears and counting.

Biologists place the ecosystem’s recovery goals at 100 bears. Over time, Kasworm said, the animals will link with surrounding but separate ecosystems, including the Bitterroot Mountains to the south, the Northern Continental Divide to the east and British Columbia to the north.

“The ultimate goal is to see bears move into the Cabinet Mountains and reproduce. We haven’t seen documented gene flow or reproduction, and only in the last few years have we seen minimal movement into the Cabinet Mountains,” Kasworm said. “That’s another step forward.”