New Study Will Estimate Grizzly Bear Population in Northwest Montana

By Beacon Staff

A new research project in Northwest Montana will attempt to identify the number of grizzly bears using hair traps.

Beginning June 7, researchers working with the U.S. Geological Survey will collect hair from wire corrals and a network of bear rubs throughout the Cabinet-Yaak Ecosystem, one of six recovery zones defined by the U.S. Fish and Wildlife Service’s Grizzly Bear Recovery Plan. The study area extends beyond the recovery zone, which borders Canada and encompasses the Cabinet and Purcell mountain ranges in the northwest part of the state, to include all 2.4 million acres where grizzly bears are believed to be living. The project is a collaborative effort among city, county, tribal, federal and state agencies, as well as partners from private industry and the non-profit sector.

Through “hair of the bear” studies, individual bears will be identified by DNA collected from almost 800 scent-baited hair corrals and more than 1,200 unbaited, naturally occurring bear rubs such as trees, posts and poles that the animals rub. The hair corrals are set up by encircling a group of trees with barbed wire and pouring liquid scent in the center of the corral. When a bear passes under or over the wire to investigate the source of the odor, the barbs collect its hair. At the bear rubs, small strips of wire are attached to the rubbed surface to facilitate hair collection. No lure or attractants are used at these sample sites; rubbing is the result of natural behavior.

All hair collection sites will be at least one-third of a mile from all structures and at least 100 yards from roads and trails, according to the USGS. This method of estimating population size was successfully used in the Glacier National Park – Bob Marshall Wilderness complex in 2008. That study found 765 bears in the Northern Continental Divide area. That population is now estimated at roughly 1,000 bears.

Researchers believe at least 40 grizzly bears make their homes in the Cabinet-Yaak.

“Getting accurate counts of infrequently encountered animals in the wild is always a challenge, especially when individuals are difficult to distinguish from one another,” USGS Director Marcia McNutt said in a statement.

“The great advantage of using DNA for counting is that it not only distinguishes individuals reliably, but also can determine how related or inbred a population has become, an important parameter in monitoring genetic diversity in the wild.”

For more information, visit the Cabinet-Yaak Grizzly Bear Project website.

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