Wildlife experts say the National Park Service was justified in killing an adult female grizzly bear this week after DNA evidence placed the sow at the sites of two fatal attacks over the summer at Yellowstone National Park.
Brian Matayoshi, 58, of Torrance, Calif., was confirmed killed by the female bear near the Wapiti Lake Trailhead on July 6 (Land Letter, Sept. 22). Less than two months later, on Aug. 26, hikers found the mauled body of John Wallace, 59, of Chassell, Mich., on the Mary Mountain trail roughly eight miles away from the first attack.
DNA evidence obtained from hair and scat samples taken at the scene of the August attack showed the bear was at the site of the second attack and may have scavenged Wallace's remains.
The two attacks were the first grizzly-caused fatalities in Yellowstone park in 25 years.
On Sunday, Yellowstone officials euthanized the 6- to 7-year-old, 250-pound sow citing public safety concerns. The bear, which had two cubs, was not put down after the July mauling because investigators determined the attack was caused in part by Matayoshi's evasive actions, which included running and yelling for help, both of which may have provoked the bear.
"Having a bear who was definitely the cause of fatal injuries in one instance placed at the scene of another fatal attack led us to the decision that we had to remove that bear for future safety issues for visitors and employees," Al Nash, a Yellowstone spokesman, said this week
But Nash said the decision to kill the bear was difficult, in part because investigators cannot prove that the sow was responsible for both attacks, or if she simply wandered onto the scene of the second attack.
Although DNA evidence suggests as many as four bears may have eaten parts of Wallace's body before he was discovered, Nash said officials do not plan to analyze the stomach contents of the euthanized bear for traces of his remains.
"That was so long ago. We're talking over a month ago here," he said. "All we can confirm was that the [same] bear was at the scene of both incidents."
Erring on the side of caution
While the Park Service acknowledged the euthanized bear "had no known history of conflicts with humans," a factor that contributed to the decision to leave her in the wild after the July attack, experts interviewed this week said Yellowstone officials were right to err on the side of caution after the DNA evidence placed the bear at the site of the second mauling.
"If this bear was involved, or suspected of being involved in two fatal incidents, it's too dangerous to keep that animal in the habitat, and they don't need to keep that animal in the habitat," said Chris Servheen, grizzly bear recovery coordinator for the Fish and Wildlife Service in Missoula, Mont. "It was a perfectly logical decision from a management standard."
Mark Pearson, conservation director for the Greater Yellowstone Coalition in Bozeman, Mont., said the decision to kill the female grizzly could actually protect other bears that also left DNA evidence at the scene of the second mauling.
"It forestalls cries for more aggressive action against a half dozen bears or more, potentially," Pearson said. "You'd have seen calls to take out the seven, eight or nine bears that left DNA evidence at the second fatality without even knowing if any of them was involved in the original death anyway."
The decision to kill the bear comes as grizzly populations in the West are growing and the bears are expanding their range to areas where they haven't been seen in decades. Wyoming currently supports about 600 grizzlies, up from 224 in 1975, when the animal was first placed on the endangered species list (Land Letter, July 7).
But despite population gains over nearly 40 years, grizzlies in the greater Yellowstone area remain classified as threatened under the Endangered Species Act, elevating the stakes for wildlife managers faced with any decision to remove or kill a wild bear.
"Euthanization of a bear is always an absolute last resort," Nash said.
The bear was first heavily sedated, then a steel rod was fired into the animal's brain -- killing it instantly and without pain, Nash said.
The sow's two cubs were taken to the Grizzly and Wolf Discovery Center in West Yellowstone, Mont., which is operated by a nonprofit that cares for displaced animals, he said. The cubs will remain in captivity and will not be introduced back into the park, he said, although it's not clear how long they will stay at the center.
In the days since reports spread about the decision to kill the bear, Nash said officials have received telephone calls and emails protesting the decision.
But Nash said park officials did not make the decision lightly, and in fact spent considerable time weighing evidence in the two cases. In addition to gathering and analyzing DNA samples, investigators were aided greatly by an eyewitness account to the July incident from Marylyn Matayoshi, Brian Matayoshi's wife.
Marylyn Matayoshi was with her husband hiking on the Wapiti Lake trail on the morning of July 6, when another hiker pointed out a female bear and her two cubs about 500 yards off the trail. Marylyn Matayoshi took photographs of the grizzly only minutes before the attack.
After the bear mauled her husband, it approached Marylyn Matayoshi, who had hidden face-down behind a fallen tree. The sow picked her up by her daypack before dropping her uninjured on the ground.
Park rangers had little trouble identifying the bear from the Matayoshi attack, but officials determined the animal acted in self-defense and was not a public threat. "So we chose to monitor her movements, but not to capture, collar, or euthanize the bear at that time," Nash said.
After the second attack, however, hair and scat samples determined that the sow was among a group of seven bears that had been to the site of the second attack, and that at least four of the bears had fed on Wallace's body. They also knew from eyewitness accounts that at least five grizzly bears had been feeding on a nearby bison carcass.
Officials then began to suspect that the bear from the July attack might have been involved in the August attack. On Sept. 28 officials captured the sow from the Matayoshi incident and used DNA analysis to compare hair samples with evidence collected from the scene of the Wallace attack, Nash said.
They found a match, though Nash said that does not mean the same bear killed both hikers.
"We don't really believe there is a way for us to definitely know which bear may have killed Mr. Wallace, or if more than one bear was involved in the fatal attack," Nash said. "We believe that's going to be beyond what we will ultimately be able to determine."
NPS has not closed its investigation of the August attack, and Nash said the agency has "ongoing capture operations" in the area to collect hair samples from other bears in the field and compare them with samples collected on or near Wallace's remains.
Park rangers have also found 17 bear "daybeds" in the vicinity of the August attack site, Nash said, so they know there's a lot of bear activity in the region.
Nash said the Park Service has captured at least seven bears in the area since the attack, and if future DNA matches are found, more euthanizations could occur.
"So far, we have only one positive identification," he said. "It remains possible but not necessarily likely that we could capture another bear, have a DNA test on the hair sample and link another animal to this attack site."
As it stands, the sow killed Sunday is the second grizzly to be euthanized at Yellowstone National Park this year.
The Park Service euthanized a bear on Aug. 1 that charged at a hiker a month earlier on Storm Point Trail on the north edge of Yellowstone Lake, he said. Rangers had catalogued 25 instances of aggressive behavior by the 4-year-old male grizzly over the past three years, and it had become clear the bear had no fear of humans.
"This bear came close to hurting someone. He had a history of getting into developed areas, of charging at people," he said. "This grizzly had begun to associate food with people, so he was a safety risk."
Streater writes from Colorado Springs, Colo.