Grizzly bears are known to displace wolves from food sources and claim the meat for themselves. But it doesn’t always work that way.

The accompanying footage, captured last Thursday in Yellowstone National Park, shows two wolves ambushing a “ginormous” grizzly bear that was approaching a carcass the wolves had previously claimed.

The startled bear took up a defensive position atop a slope as other wolves appeared, then the bear charged down the slope toward the carcass.

ALSO: Rattlesnake found in Texas bedroom, striking image stirs emotions

From photographer Julie Argyle via Instagram:

“A carcass, wolves, and a ginormous grizzly. After watching wolves feed on a carcass for most of the day, we noticed something moving near the tree line. There, coming towards the carcass at a dead run was this amazing Grizzly.

“The wolves had retreated to the sage and most were sleeping, unaware of the bear. Once the Bear reached the area where the wolves were, the wolves must’ve smelled him, and they immediately let out a low howl, stopping the bear in his tracks, and then all chaos broke out.”

Argyle told FTW Outdoors that the bear eventually reached the carcass, which was beyond her field of vision, but 20 minutes later the wolves were spotted "chasing it back up the slope and up to the tree line."

Grizzly bears are fresh out of hibernation and eager to pack calories. In early spring much of the diet for bears and wolves comes from winter-killed bison and elk, whose carcasses become uncovered during the thaw.

It’s likely that the bear in the footage returned to the carcass at some point.

This article originally appeared on For The Win: Yellowstone grizzly bear ambushed by wolves in battle over carcass