Yellowstone Grizzly Bear vs. Pack of Wolves Filmed in 'Once in a Lifetime' Sighting

Stunning footage has emerged showing the moment a grizzly bear was surrounded by a pack of wolves and escorted from an area of Yellowstone National Park.

A video of the encounter was captured by Tied to Nature tour operator Adam Brubaker who was leading a group of visitors through a section of the park called Hayden Valley last Friday, an area that is also home to herds of bison and coyotes.

Brubaker, a qualified naturalist, described it as a "once in a lifetime" sighting on his Tied to Nature Facebook page. "I had the awesome opportunity to share this once in a lifetime wolf and grizzly sighting while on tour in Yellowstone today," he wrote.

"This grizzly was foraging in the far end of the valley when the wolves started to cross his path. The grizzly started standing up on his hind legs to get a better view of what was going on and then started to approach the wolves. Soon the rest of the wolf pack appears and escorts the bear into the trees," the Yellowstone guide said.

Brubaker said it was "hard to say" if the grizzly bear was trying to seize a wolf's kill, but one of the white-colored wolves in the pack did appear to have a "bloody face."

According to the National Park Service (NPS) website, most interactions between bears and wolves at the park involve food, with both species typically avoiding each other.

"Bears may benefit from the presence of wolves by taking carcasses that wolves have killed, making carcasses more available to bears throughout the year," the NPS said. "If a bear wants a wolf-killed animal, the wolves will try to defend it; wolves usually fail to chase the bear away, although female grizzlies with cubs are seldom successful in taking a wolf-kill."

"I could see that the two species were probably going to cross paths but I did not expect what was going to happen," Brubaker told Newsweek.

"For many people, this would be a once-in-a-lifetime encounter. Neither the wolves nor bears were injured. I believe I saw the same bear yesterday out in the same place this time with no wolves around. I have been a guide in Yellowstone for seven years and visiting the park for 20 and every day can offer something new or different."

The park service said on its website that the way bears and wolves behave when they interact can depend on many variables, including their respective age, sex, reproductive status, and whether they are hungry.

The wolves did not appear to attack the bear, and Brubaker could be heard telling the tourists in the video that it was not something he had ever seen before.

"I don't know if puppies are with this pack right now, but they are just moving him out. They are saying 'hey, we are coming through and we don't want you here,'" he said in the clip, which attracted hundreds of comments on the social media platform.

The NPS has said only a "few instances" of bears and wolves killing each other have previously been documented, with the wolves mostly targeting bear cubs.

In the comments section under the Facebook video, Brubaker said the bear came back out from the wooded area as soon as the large wolf pack moved on.

USA Today reported the wolves were believed to belong to the Wapiti Lake Pack. At the end of last year, the pack was deemed to be the largest in Yellowstone, with 19 wolves, by Yellowstone Wolf, a project tracking packs in the 3,472 square-mile park.

This article was updated with comment from Tied to Nature guide Adam Brubaker.