You might think not many creatures could get away with biting a grizzly bear in the rear end – and, let’s be honest, you’d be right.

But a grey wolf in Yellowstone National Park recently demonstrated that sometimes grizzly-butt-biting is not only apparently called for, but also possible to pull off without bodily dismantlement. There’s footage to prove it:


 

The video was taken along Crystal Creek by Gary Gaston on the morning of September 4th. This is on the legendary Northern Range of Yellowstone, famed for its herds of bison, elk, pronghorn, and other ungulates and excellent wolf- and bear-watching opportunities.

The presence of the dark-coloured wolf, the grizzly, and a whole squad of ravens suggested to Gaston that a carcass was nearby – most likely, he told For the Win/USA Today, the remains of an elk.

Whether wolf-killed, bear-killed, or felled by some other cause, dead animals are classic scenes of wolf/grizzly encounters. As the great field biologist Adolph Murie, who studied both carnivores for many years in Alaska’s Denali National Park, put it in The Grizzlies of Mount McKinley: “Both the grizzly and wolf are fond of carrion; consequently the two species renew acquaintanceship occasionally at a carcass.”

Gaston captured further footage of wolf-inflicted butt-biting a week or so later when he came across a yearling canine chomping on a bear's rear end in Yellowstone's Lamar Valley:


 

It's unclear if a carcass played a role in this second instance of backside nibbling – it's possible the wolf was simply trying to see off the bear in order to eliminate any competition for food and resources.

On the whole, both in Denali and Yellowstone and likely other corners of their shared North American range, grizzlies – perhaps the most hot-tempered of the world’s brown-bear subspecies – tend to have the upper hand/paw over wolves when the species clash. That’s especially true of large male grizzlies (“boars”), which are confident enough in their size, power, and swagger to shove even whole packs of wolves off kills:

But even female grizzlies (“sows”) with cubs sometimes attempt to drive wolves away from carcasses, though such behaviour may put the young bears at risk of being killed.

Wolves are no pushovers. Whether they’re defending or trying to commandeer a carcass, or – in another of the common situations that bring the species together – protecting pups at a den or rendezvous site from a too-close-for-comfort bear, they use speed, agility, and, frequently, teamwork to harass grizzlies. Last year, Yellowstone’s Wapiti Lake Pack was filmed running off a good-sized grizzly that quickly tired of being surrounded and charged on all sides.

Gaston’s footage shows that wolf/grizzly encounters are (a) sometimes one-on-one and (b) not always particularly tense or high-octane affairs. The grizzly’s defence from the wolf’s posterior nips is not a furious counterattack but rather the decidedly low-key, but pretty effective, tactic of ... sitting down.

It calls to mind yet another Yellowstone incident from 2020, when a huge boar grizzly killed a bull elk in the Yellowstone River near the park road and then proceeded to wow onlookers by feasting on it in full view for days afterward. Wolves showed up, surely with scavenging on the mind, and the grizzly – who seemed to ascribe to the credo of “work smarter, not harder” – mainly defended the carcass by lying on top of it and looking big and bad: