How Wildlife Investigators Found a Killer Grizzly in Yellowstone

A grizzly bear crime
April 2 2012 6:00 AM

A Death in Yellowstone

On the trail of a killer grizzly bear.

(Continued from Page 7)

The John Wallace mauling would take place just eight weeks later, and only a few miles from where Brian Matayoshi had been killed. But Chris Servheen and Kerry Gunther both say that at first they didn’t assume the cases were related. The Wallace investigation faced significant obstacles. The investigators, you’ll remember, didn’t reach his body until a day after the attack. Scientists couldn’t get any DNA from the bear hair and saliva found on Wallace’s body. The genetic material might have degraded in the body bag by the time the autopsy was performed, or washed away in that storm the night after Wallace’s death.

But as the investigation went on, Servheen and Gunther realized that there was mounting evidence against the Wapiti sow. They had the bloody paw prints from a mother bear and cub. Then they found a DNA match, between the scat that had been dropped next to Wallace's hat and bandanna and a sample taken from an animal hair that had snagged on Brian Matayoshi's glasses while he was being attacked the month before. The Wapiti sow—a bear that had already mauled to death one Yellowstone tourist—had been at the scene of the second killing, too.

The fact that she'd been at the scene didn't prove she was guilty, but the evidence continued to pile up. DNA from scat found about 25 feet from Wallace’s body turned out to be a match for her distinctive blond cub. The bloody, big and little paw prints were consistent in size with her own and those of her young cub, and there were no other female grizzlies with similar-aged cubs roaming Hayden Valley, as far as the rangers could tell. She was by far the most likely suspect in the Wallace death. It was time to bring her in.


The easiest way to catch a bear is with something called a culvert trap, named for the tubular devices that channel water. On Aug. 26, the day Wallace's body was found, rangers closed off nearly the entire Hayden Valley, comprising about 10 percent of the Yellowstone parkland, and, in the weeks that followed, they baited aluminum and stainless-steel tubes with animal carcasses in 10 different locations—including the sites of both the Wallace and Matayoshi maulings, next to the rushing water in Otter Creek, and near the burbling geysers of Crater Hills. Starting at the end of August, rangers rode out to check each of these traps on horseback, hoping to find the Wapiti sow.

A grizzly in a culvert trap. Photo taken at the Grizzly and Wolf Discovery Center.
Photo of a display at the Grizzly and Wolf Discovery Center. Original photo by Kevin Frey.

Photograph for Slate by Jessica Grose.

At first the traps only succeeded in luring some very old male bears, the ones that are most aggressive around carrion. Younger, smaller bears are more skittish about fighting over meat, and so are mother bears with young cubs. Gunther and his men knew the Wapiti sow would be difficult to catch, but when she hadn’t turned up by late September, they started getting nervous. Yellowstone’s bears start to den up for the long winter in October, and they’re generally all hibernating by the end of November. If they couldn't trap her before she went into hibernation, they might lose her for good. In the spring, she could find a new home range somewhere in the deep woods of Yellowstone’s nearly 2.2 million acres, hidden under the forest cover.

It was maximally frustrating, because they were seeing the Wapiti sow and her cubs all the time from their regular aerial missions over Hayden Valley. The larger cub’s blond mug made the trio impossible to miss. But Gunther's crew was hoping to avoid their Plan B, a mission to shoot the bear from the sky with a Telazol-filled dart gun. That would be dangerous for a ranger, who would have to dangle from a helicopter for the shot. It would also be more dangerous for the bear, which could be killed painfully if shot in the wrong place.

The aerial-gunning maneuver was set for the morning of Sept. 29. But on the evening of Sept. 28, bear managers received an automated radio signal from one of their culvert traps along the Yellowstone River, about 6 miles from the site of the Wallace killing. When rangers arrived the next morning, they found the Wapiti sow in the aluminum tube, and she was agitated. Her cubs were darting around the trap, making little bawling noises. It didn’t take much to corral them into a culvert trap next to their mom's—they just wanted to be near her, and they were confused.

On Oct. 1, hair and blood samples from the sow and her cubs were successfully matched to those found at both the Wallace and Matayoshi crime scenes. At that point, the group of federal, state, and local officials who decide on the fate of grizzlies involved in crimes—including Chris Servheen and Kerry Gunther—knew what they had to do. The Wapiti sow was to be euthanized the next day, on Gunther’s birthday.

He had to do so knowing that he would be shrinking a population of about 600 grizzly bears in the Yellowstone region. As a reproductive female, one of about 250 now living in the Yellowstone ecosystem, the Wapiti sow was even more valuable. Bear managers count on having 91 percent of the bears like her survive from year to year to keep the grizzly population thriving.

Servheen and Gunther felt they had made the right decision, but acknowledged they would never know for sure which bear killed Wallace. It would be months before the investigation would be completed, and its full details released to the public. Additional DNA analysis done in January would show that hair found on a log about 20 meters from Wallace’s body belonged to a different female grizzly, No. 693 in their DNA database. After the release of the official report on Wallace’s death in March, Yellowstone’s superintendent Dan Wenk said that he was considering euthanizing No. 693, even though she had no history of aggressive behavior. Such a decision would be one taken in extreme caution, says Servheen. As far as he and Gunther were concerned, they’d done the best they could, based on the information at hand. They also knew that the decision might not be popular, and they girded themselves for blowback.