How Do You
Count Grizzly Bears?

By Linda Zajac ~ Photos courtesy of U.S. Geological Survey

Carefully.

	Researchers set up a fence to capture grizzly-bear hairs . . .
	Then they pour a scent that grizzlies can’t resist.

Roaming the wilderness in search of wild huckleberries, a grizzly bear sniffs the air. Something smells good. Like a kid tracking the aroma of fresh chocolate-chip cookies, the curious bear follows the scent.

Twigs snap. The 400-pound animal stumbles through the shrubs. It brushes against a barbed-wire fence. Finally, the search is over.

What did the grizzly bear find? It certainly wasn’t cookies. It was a pile of branches and pine needles soaked in rotten cattle blood and fish oil.

On the prairies, peaks, and plains in northwest Montana, researchers are on a mission. How many grizzly bears can they find on eight million acres? No one knows for sure. To protect the bears, researchers need to keep track of how many grizzlies there are and where they live.

How to Snag Bear Hairs
Field crews set up more than 2,500 scent stations to attract eager grizzly bears—and collect hair samples to help count the bears.

At each station, the crews create a corral by wrapping two rows of barbed wire around several trees. In the middle they put a treat. It’s a pile of branches that smells so bad it might make you sick.

Grizzlies love the scent. “They like to rub their necks and sometimes roll in it,” says Kate Kendall, a scientist with the United States Geological Survey.

A bear rolls in the stinky scent. Each bear must go through the fence to investigate the smell, and the fence catches a few hairs as the bear passes through.

You might be wondering what the researchers do when the grizzly bear arrives at a scent station. The researchers aren’t there waiting for the bears. After they set up the scent station, they leave. It’s not the grizzly bears the researchers are after—it’s their hair.

When a bear inspects the stinky lure, it has to cross the barbed wire, which harmlessly snags some of the bear’s hair. “We put the hair-snag stations out for fourteen days,” says Kendall. “Most of the bears come in during the first week.”

Secrets in the Hair
The hair samples go through a lengthy process. First, researchers collect the hair with tweezers. Then each sample is examined. Researchers choose only samples that have the hair roots, or follicles.

Next, each sample is soaked in a special liquid that breaks down the coating around the bear’s genetic information, or DNA. The DNA samples all look alike. But, like fingerprints, they are very different. You may be amazed at the information that is hidden in the DNA.

Every living thing has DNA. This group of molecules is a complete set of instructions for growing that individual—such as a germ, a tree, or a bear. By studying the DNA, researchers can tell if the hair came from a black bear or a grizzly bear. They can also tell if the bear was male or female.

A tuft of fur can tell a lot about a bear.

In fact, every single grizzly bear has different DNA. So the DNA is also like a name tag. Researchers won’t count the same bear twice because they will know if they have two hair samples from the same bear.

By keeping careful records, researchers will know how many different bears visited the scent stations. The study area is huge. Scientists know that some bears may never enter the stations. But their count of individual bears identified by their DNA from hair samples will help them estimate the total number of bears that live in the area.

To protect the grizzly bear, researchers need more information. By collecting hairs, they expect to have a population estimate for the northwest corner of Montana soon. They are only hairs away from an answer.

Why Bears Count
Why is it important to know how many grizzlies there are? Because outside of Canada and Alaska, there aren’t many grizzlies left.

No one knows how many of the bears roamed North America before European settlers arrived. One estimate says 50,000.

As settlers moved west, they moved onto land that was home to the grizzly bear. They built houses, roads, and towns. Grizzly bears were often shot or poisoned. People feared the bears would take their food, livestock, or even their lives.

By 1975, scientists believed that fewer than 1,000 grizzlies still survived. In that year, the bears came under the protection of the Endangered Species Act. Now, 1,200 to 1,400 grizzlies are estimated to live in the United States. But how accurate is the estimate? And is the number going up or down or holding steady?