HELENA, Mont. — An investigation into the second of two fatal grizzly bear attacks last summer at Yellowstone National Park was unable to conclude if the same bear was responsible for both deaths, a report released Monday said.
But DNA tests show the bear that killed California hiker Brian Matayoshi in July fed on Michigan hiker John Wallace with one of her cubs in August, and evidence of two other bears in the area where Wallace's body was found much farther away – 65 feet and 492 feet from the body.
The report indicates there is no "clear evidence" to identify the bear that attacked and killed the 59-year-old Wallace from Chassell in Michigan's Upper Peninsula.
"The presence of bloody adult and cub tracks suggests that the adult female that killed Mr. Matayoshi and one of her offspring were likely involved in the consumption of Mr. Wallace's body," the report said. "This bear may or may not have been involved in the attack on Mr. Wallace, but this bear was at the fatality site."
Park officials decided against capturing or killing the mother bear, or sow, after Matayoshi's death. Investigators then concluded that Matayoshi and his wife had surprised the sow and its two cubs and the bear had acted defensively.
The report on Wallace's death by the Interagency Grizzly Bear Committee said it is not known why the bear or bears attacked Wallace on Aug. 25. Wallace was hiking alone and there were no witnesses.
The sow was euthanized last fall after DNA evidence linked it to the scene of the second mauling. The sow's cubs were taken to the West Yellowstone Grizzly and Wolf Discovery Center.
Park spokesman Al Nash on Monday defended the park's decision not to remove the grizzly after the first attack.
"We feel we made the best decision available with the information we had subsequent to the attack on Mr. Matayoshi," Nash said. "Subsequent events prompted us to take a look at the unique circumstances surrounding the Wallace incident and take action based on that information available."
Wallace stopped on the side of the Mary Mountain Trail in Hayden Valley, about eight miles from where Torrence, Calif., resident Matayoshi and his wife were attacked on the Wapiti Lake Trail, according to the report. It was probably morning, because Wallace's lunch was found uneaten.
Wallace appears to have taken off his daypack and may have been snacking on an energy bar when he was attacked.
Bite marks on his hand and arm indicate that Wallace tried to fight back, but he was not carrying bear spray.
A father and daughter hiking along the trail the next morning found Wallace's body partially on the trail and partially buried next to the trail "consistent with the food caching behavior of a bear," the report said.
The night before the attack, campground personnel gave Wallace a lecture about food storage and bear safety when he arrived at the Canyon Village campground. Wallace said that "he did not need to hear that information and that he was a `grizzly bear expert,'" the report said.
A sign posted at the Mary Mountain trailhead warned hikers that they were entering bear country, recommended carrying bear spray and recommended against hiking alone.