Northern Continental Divide Grizzly Population Booming, Scientists Say

Dec 13, 2016

The grizzly bears in the Northern Continental Divide Ecosystem (NCDE) have spoken, and they are telling us that everything we’re doing to recover their population has worked. That was the message from state and federal bear experts at the Interagency Grizzly Bear Committee Winter Meeting today in Missoula.

Dr. Kate Kendall is an emeritus scientist with the U.S. Geological Survey who came out of retirement to present her findings on population trends:

"We have three independent lines of evidence showing that the grizzly bear population in our ecosystem has expanded significantly since 2004," says Kendall.

Kendall has been collecting hair snags that bears leave on natural rub trees throughout the ecosystem. Her genetic data shows the population is growing at a rate of 5.6 percent per year.

"It’s higher than I thought, expected to see," says Kendall. "That’s a very healthy growth rate and suggests that there’s plenty of good habitat for bears and good protection for them."

That growth rate is slightly higher than what Dr. Cecily Costello, a wildlife biologist with Montana Fish Wildlife and Parks, found. She’s been capturing live bears and tracking their survival and reproductive rates. Her data also shows a substantial increase in the NCDE population, up from about 760 bears in 2004 to just above 1,000 bears now.

Other research presented at the meeting indicates that genetic diversity in the NCDE population is increasing too, and that bears are filling into areas that historically had lower density.

"We think that those are benchmarks which would indicate that the population has recovered," says Costello. "So we’re confident that we have the data to justify a process of trying to get them de-listed."

The U.S. Fish and Wildlife Service is working on a de-listing proposal for grizzlies in the Yellowstone ecosystem, but there’s no formal proposal to de-list the bears in NCDE at this time.