Bear researchers study grizzly bear health, habits and habitat | Montana News

Can grizzly bear births be detected remotely?

Data so far seems to say yes, biologists can often detect bear births by analyzing activity data from radio and GPS tracking collars put on grizzly bears.

The apparent correlation between parturitions (observed after spring caving) and spikes in sow activity during caving (detected by collars) was shared by Cecily Costello on Thursday. Costello, who received his PhD from Montana State University in 2008, is a research biologist in the Montana Department of Fish, Wildlife & Parks. She oversees the agency’s grizzly bear trend monitoring program for the Northern Continental Divide Ecosystem, which surrounds one of the designated protected species recreation zones. She is also Chair of the Science Team for the NCDE Subcommittee of the Interagency Grizzly Bear Committee.

Costello shared the research development along with reviews of a wealth of other ongoing and potential future studies at the NCDE subcommittee’s winter meeting Thursday in Missoula. The two-day gathering at the Doubletree Missoula Edgewater Hotel ends Friday at noon.

In interviews with dozens of frequently collaborating wildlife biologists, non-profit workers, researchers, bear managers and officials from a range of state, federal and tribal agencies, Costello stated that using collar data to detect bear births “is working really well so far. ”

“It’s not 100%,” she said, “but it had a pretty high level of accuracy in estimating.”

And once bears are born, Costello and other researchers hope to figure out where and when they go. Because some bears leave the NDCE, merging birth rates with NCDE population estimates could result in an overcount of bears because it does not take into account the number of bears leaving the ecosystem each year.

“As males get older, they move farther from their natal territory compared to females,” she said, “and after that they stay out for a while.”

A more accurate understanding of the rates and times at which males and females are leaving the ecosystem could lead to more accurate population estimates of how many bears remain in the ecosystem, according to Costello.

Another study is more interested in what bears do when they leave a native ecosystem. Costello shared a map researchers created of known granaries on the prairie of the Rocky Mountain Front, immediately east of the NCDE. By comparing the tracking collar data to grain bin locations, the researchers hope to determine the frequency and duration of bear visits to the bins; whether the bears seek out the trash cans or just opportunistically eat from them when they stumble across them; and whether there are common features in the bins most commonly raided by bears.

An overlapping study, she said, is examining the effectiveness of using livestock guard dogs to deter bears from raiding trash cans.

Costello made the switch from what goes into bears to what goes into bears and says she was approached by Brian Balmer, an environmental pollutant specialist at the US Fish and Wildlife Service. Balmer, she said, specifically wants to study the effects of mine contaminants, such as heavy metals and semimetals, on grizzly bears. The NCDE region is dotted with mines more than a century old, many of which were abandoned and constructed long before environmental regulations were put in place to prevent contamination.

“No one has ever really looked at whether these affect grizzly bears or even black bears in this area,” she said.

Costello said she is willing to work with Balmer to provide existing blood and hair samples that he can use to determine historical levels of contaminants in bears, as well as samples from recently captured or deceased bears.

A “retrospective metals analysis,” she said, “could provide a look through time to see if there’s been a change.”

Other analyzes focus more on the state of the bear habitat itself.

Kathy Ake of Flathead National Forest serves as the NCDE Habitat Database Manager. She reported that in 2021 she prepared a semi-annual report on the extent of motorized access in the NCDE in 126 sub-units. Open roads have been shown to increase bear mortality and displace bears from productive habitats.

More accurate mapping, she said, could show that a street is actually in a slightly different location than where it historically appeared on maps. This could result in more road kilometers being traveled in one sub-unit and less in another, changing the percentage of road travel in both. But actually nothing has changed in these cases on site, she emphasized.

Overall, 71% of the NCDE is “safe core” with minimal road density. This represents an increase of more than 10,000 acres from 2019 and an increase of more than 56,000 acres from 2011. However, only about 17,000 acres of the change since 2011 was due to active land management; the rest was due to things like better mapping data or land swaps, neither of which really change the conditions on the ground.

“A lot of changes on the Blackfeet (reservation) and Rocky Mountain fronts,” she said. “A lot of it is land swaps, I can tell you.”

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