USGS CoreCast

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Jennifer LaVista: Welcome and thanks for tuning into this episode of CoreCast, I’m Jennifer LaVista. The size and distribution of grizzly bear populations in North West Montana has just been released been the U.S. Geological Survey. To learn more about this study, I called USGS Research Biologist, Kate Kendall, to bring us up to speed on these furry creatures. Kate, thanks for joining us.

Kate Kendall: My pleasure.

Jennifer LaVista: Tell me, why is it important to study grizzly bears in this area?

Kate Kendall: It’s important because there are only five grizzly bear populations remaining south of Canada. And although this population has been listed as threatened since 1975, there was no ecosystem-wide information about how the population was doing.

Jennifer LaVista: So how did you go about setting them?

Kate Kendall: Because bears are difficult to find in our area, because we have very thick vegetation, we selected methods that don’t require us to observe bears in order to sample and count them. We collected bear hair from barbed wire hair traps and natural bear rub trees and use the DNA analysis to identify the species, sex and individual identity of the grizzly bears and black bears that left the hair behind.

Our hair traps consist of 100 feet of barbed wire stretched around several trees at knee height to form a small coral. And then we placed a scent in the center and when bears crossed the wire to investigate, they usually leave hair snagged on several barbs.

Bear rub trees are another good source of hair. And they don’t require the use of any sort of attractant. Bears often rub their backs and shoulders on trees, signposts, power poles as a form of chemical communication with other bears. We just took advantage of that natural behavior to provide a second source of bear hair samples.

Jennifer LaVista: Tell me a little bit about these videos that I’m seeing.

Kate Kendall: Well, to learn more about how bears respond to our hair traps and their behavior at rub trees, we set up remotely triggered still and video cameras at hair snare sites. We’ve gotten some really fantastic footage that gives us a window onto the bears world. The video of bears at rub trees are especially interesting and amusing. And they definitely look like the bears enjoy the process of rubbing on these trees. We were amazed when we first started getting this video footage.

Jennifer LaVista: Do you have a favorite video?

Kate Kendall: Oh, we’ve got lots of favorites but I think the bears, the grizzly bears, there’s a couple of them, one we call “the dancing bear” that just gets this kind of rhythm going. Rubbing on the tree and kind of shimmies on down to a squat and then back up again, that’s one of them. And then there’s another one that he kind of does this hand jive thing while he’s rubbing and it’s just very amusing.

Jennifer LaVista: So what did your study find?

Kate Kendall: Well, during 14 weeks that we sampled in 2004, we collected 21,000 grizzly and black bear hair samples from our hair traps and 13,000 hair samples from bear rub trees. From individual bears that were identified from the hair samples, we estimated that in our 7.8 million-acre study area, the population had 765 grizzlies.

Jennifer LaVista: Wow.

Kate Kendall: And then by plotting the location of all records of bear sightings and DNA detections from 1994 to 2007, we found that grizzly bears had expanded their range by 2.5 million acres outside of the area thought to be occupied in 1993.

Jennifer LaVista: Are there any other agencies or organizations that are interested in this information?

Kate Kendall: We had 12 state, federal and tribal agencies that manage grizzly bears, or their habitat, that were partners in this study and are very interested in the results. The U.S. Forest Service, Flathead, Lewis and Clark, Kootenai and Helena and Lolo National Forest. Glacier National Park, Montana Department of Fish Wildlife and Parks and the Department of Natural research conservation. The Blackfeet Nation, the Confederated Salish and Kootenai Tribes, the U.S. Fish and Wildlife Service and the Forest and Land Management.

The agencies that were cooperators in this study use the information to design their programs and their management policies in order to encourage and promote grizzly bear population recovery. And they may use it to design timber harvest strategies that are compatible with grizzly bear use. Make road density standards that also are good for bears.

We also have numerous private organizations that also cooperated with the study and are interested in the results. Such as Plum Creek Timber Corporation, the Nature Conservancy’s Pine Butte Swamp Preserve, the Boone and Crockett Roosevelt Ranch, Northwest Connections, the Glacier National Park Fund and thousands of private citizens.

Jennifer LaVista: How can we build on this study to continue to have a strong understanding of how many bears are in the ecosystem?

Kate Kendall: Well, we’re looking into how to design hair snare sampling to effectively monitor grizzly and black bear population trends using non-invasive methods such as hair traps and rub trees alone or in combination with other sources of data such as management records. Because of the large proportion of the population that can be sampled very quickly with hair snaring, this approach promises to be an effective way to monitor bear population, abundance and growth rate over time.

Jennifer LaVista: Kate, is there anything you’d like to add?

Kate Kendall: This study was successful in large part due to the hard work of my core staff and hundreds of field technicians. I just want to acknowledge their enthusiasm and dedication because it was really critical to the great results that we got.

Jennifer LaVista: Excellent. Well, thank you so much for joining us, Kate.

Kate Kendall: Well, thanks for having me.

Jennifer LaVista: And that does it for this episode of CoreCast. To learn more about the Northern Divide Grizzly Bear Project, check out NRMSC.usgs.gov or click on the link at the bottom of the CoreCast page.

Speaker 3: Do not forget to enter the “Be a CoreCast Host for a Day Contest”. The lucky winner, you guest it, gets to host their very own episode of CoreCast. The contest ends September 26 so make sure to enter by sending your name and email address to corecast@usgs.gov.

Learn more about the contest by listening to episode 60 of CoreCast at usgs.gov/corecast. Remember, we’re only using your contact info for the purposes of picking a winner. If you’re under 18, get your parents’ permission. USGS employees and their immediate families are not eligible.

Jennifer LaVista: CoreCast is a product of the US Geological Survey, Department of Interior.

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