A grizzly sow linked to two fatal maulings of hikers in Yellowstone National Park has been killed by rangers, and her two cubs have been placed in an educational zoo outside the park, Yellowstone Superintendent Dan Wenk announced Monday.
The 250-pound sow, estimated to be six or seven years old, was tied to both the mauling of Brian Matayoshi, of Torrance, California, on July 6 and that of John Wallace, of Chassell, Michigan, in late August.
While Mr. Matayoshi's wife witnessed her husband's mauling, Mr. Wallace was hiking alone on the Mary Mountain Trail and no other hikers witnessed his death. However, DNA tests on bear hair and scat samples collected from the scene where Mr. Wallace's body was found on August 26 matched the sow, the superintendent said.
In the first mauling, a review board concluded that the sow was acting defensively in attacking Mr. Matayoshi. But without witnesses, park officials couldn't explain why Mr. Wallace, 59, was attacked, or even if the sow had killed him.
“We will more than likely never know what role, if any, the sow might have played in Mr. Wallace’s death due to the lack of witnesses and presence of multiple bears at the incident scene,” said Superintendent Wenk. “But because the DNA analysis indicates the same bear was present at the scene of both fatalities, we euthanized her to eliminate the risk of future interaction with Yellowstone visitors and staff.”
A small number of grizzlies had been trapped by park biologists since Mr. Wallace's body was found so they could be DNA tested. After hair samples were taken for testing, the bears were released wearing radio collars so they could be tracked and, if necessary, recaptured if a match was made.
The female grizzly was captured last Wednesday, September 28. Her two cubs were captured the next day and placed in the Grizzly & Wolf Discovery Center in West Yellowstone, Montana.
The sow was euthanized on Sunday morning, October 2. She was not relocated to the Discovery Center with her cubs, park officials said, because (A)dult bears that are removed from the wild do not adapt well to captivity."
In the case of Mr. Wallace's mauling, park officials determined that at least nine grizzly bears were feeding on two bison carcasses in the area, including one carcass that was located 150 yards from where Mr. Wallace was hiking alone on the Mary Mountain Trail. Seventeen bear “daybeds” were also found in the same vicinity, they added.
Park officials plan to continue capture operations, reconnaissance flights, and DNA sampling and testing through the fall to determine whether any other grizzlies were involved with Mr. Wallace's death. Any future management decisions will be made on a case-by-case basis for any additional bears that are captured and provide a DNA link to the scene, they said.
Yellowstone hosts over 3 million visitors a year, with an average of just one bear-caused human injury a year. To the best of anyone's knowledge, this is the first time in the park's history that there have been two fatal bear attacks in one year. Since the park was established in 1872, there have only been seven recorded fatal maulings, according to park officials.