SALMON, Idaho (Reuters) - A hiker killed by a mother grizzly bear this summer in Yellowstone National Park may have unwittingly helped provoke the attack by running from the animal, a report released on Tuesday said.
The final report on the incident, marking the first fatal bear mauling in Yellowstone since 1986 and one of two such attacks this summer, did not alter earlier conclusions that the grizzly involved had acted to protect its young.
But the report suggested that the victim, Brian Matayoshi, 58, of Torrance, California, might have survived his July 6 encounter with the grizzly had he and his wife, Marylyn, heeded advisories posted on signs in Yellowstone's bear country.
Investigators determined that the female grizzly was provoked by a perceived threat from the couple, who were out hiking along the Wapiti Lake Trail when they happened on the bruin and its two cubs foraging for food.
The Matayoshis first saw the grizzly and its cubs from a distance before proceeding along the trail away from the animals, according to the report released by Yellowstone rangers and federal and state bear managers.
A short time later, the pair unknowingly backtracked toward the grizzly, spotting the bear just 100 yards away, then hurriedly retreated, looking behind to track its movements.
Marylyn Matayoshi told officials the bear "started coming at us, and Brian said, 'Run,'" which they did, while yelling.
The grizzly attacked the husband first, puncturing a vital artery in his thigh. The bear then lifted his wife by her backpack, dropped her, and moved quickly away from the area.
Marylyn Matayoshi said she used a jacket as a tourniquet for her husband's leg injury, and that after one long, last breath he neither spoke nor moved again. Unable to get reception for her cell phone, she hollered for help.
Investigators said the Matayoshis were not carrying bear spray, despite trailhead signs advising it and warning of danger as hikers entered bear country. One sign cautioned, "If a bear charges stand still, do not run."
Officials said the bear's chase response was likely heightened by the Matayoshis' instinctive reactions to flee.
"In addition to the unfortunate circumstance of being at the wrong place at the wrong time, a possible contributing factor to the chase that ensued was that the victims ran from the bear while screaming and yelling," investigators said.
A surgeon hiking nearby heard the shouts and logged one of two 911 calls by his hiking party.
"I'm a trauma surgeon, I can give this person medical assistance, but only if you guys say I should go in," the physician, whose name was redacted from transcripts, told a dispatcher in a recording of the call.
It was not clear what role the surgeon may have played in the aftermath of the attack. But the report said Brian Matayoshi died shortly thereafter from blunt-force trauma and blood loss from his arterial wound.
Because the bear was believed to have behaved in purely defensive manner, and had no known previous conflicts with humans, park authorities decided to let it roam.
A second Yellowstone hiker was found dead the following month from a separate grizzly attack.
Yellowstone spokesman Al Nash said on Tuesday that three bears have since been trapped near the site of the second attack, and a DNA analysis of hair samples is under way.
Nash said officials have not yet "ruled out or ruled in" the possibility that the female grizzly from the July 6 mauling was involved in the subsequent fatality.
Last Friday, a grizzly killed a hunter after the man's friend shot and wounded the animal in the mountains that straddle northeastern Idaho and northwestern Montana.
That brought to three the number of deadly encounters so far this year between humans and grizzlies in the Lower 48 states, where they are listed as a threatened species.
That compares to an average of one fatal attack every two years, said Gregg Losinski, member of a federal-state task force on grizzlies. He said overall conflicts between grizzlies and humans are so far fewer this year compared to last year.
Editing by Steve Gorman and Cynthia Johnston