Yellowstone National Park officials euthanized a grizzly bear Thursday after DNA tests confirmed it attacked and killed a hiker last week, a park spokeswoman said.

The adult female bear was killed because it had eaten part of the Montana man's body and hid the rest, which is not normal behavior for a female bear defending its young, spokeswoman Amy Bartlett said.

"If a bear consumes an individual, it's not allowed to remain in the population," she said. "It's not a risk we're willing to take."

The bear's two cubs also fed on the body, park officials determined, but arrangements were being made to transfer them to a zoo, Bartlett said. If no zoo had been willing to take them, the cubs likely would have been killed, too.

"Cubs can adapt to a facility much easier, and there is no danger of them learning humans are food," she said.

An autopsy confirmed 63-year-old Lance Crosby of Billings died of a bear attack. He worked as a nurse in the park's medical clinics and was hiking alone and without bear spray in the park's Lake Village area.

His body was found by park rangers Friday about a half-mile from the nearest trail. It was hidden by dirt and pine needles and had wounds that indicated Crosby tried to fight back.

Park officials captured the adult bear that night and its two cubs later. DNA tests confirmed bear hair samples collected next to Crosby's body belonged to the 259-pound grizzly and teeth wounds found on Crosby's body also matched the bear, which was at least 15 years old, Bartlett said.

No other bears had been spotted in the area at the time of the attack besides the grizzly and the two cubs.

Park officials received the DNA test results Thursday, and the bear was quickly euthanized. Officials heavily sedated the bear before firing a captive bolt into its skull, Bartlett said.

Yellowstone officials had previously said they would euthanize the bear if the tests confirmed it was the attacker. That prompted a backlash by people who objected to killing the grizzly when the hiker hadn't take precautions to avoid an attack by carrying bear spray or hiking with another person.

Hundreds of calls and emails over the bear's fate have poured into park offices over the past week, Bartlett estimated.

Montana Gov. Steve Bullock's office received more than a dozen calls and emails from people seeking the governor's intervention to spare the bear, Bullock spokesman Mike Wessler said, even though the state had nothing to do with the National Park Service's decision.

Arrangements were being finalized to move the cubs to a facility accredited by the Association of Zoos and Aquariums, park officials said. Bartlett declined to say where they were going, but said the facility was expected to make an announcement Friday.

The area surrounding the site where Crosby was attacked has been closed to hikers as a precaution. The closures were to be lifted Thursday.

Crosby is the sixth person killed by grizzlies since 2010 in and around Yellowstone. There are an estimated 750 bears in the park and nearby areas of Montana, Idaho and Wyoming.

Bears involved in fatal attacks are not always killed, particularly when the attack is considered a defensive one in which the animal was protecting its young.

"Had this bear just had a defensive attack, we would probably be looking at a different outcome," Bartlett said.