A video by the team at Yellowstone national park shows the extraordinary sight of a grizzly bear hunting alongside a pack of wolves, only to make off with their prey.

The footage, posted to the National Parks Service Facebook page in December, shows the multi-species pack hunting a large herd of elks. A few wolves break away to follow a smaller number of elks, and are successful in chasing a cow elk down.

Once the wolves have their kill, the bear rejoins them, grabs their meal, and runs off with it.

The sneaky act of one species stealing food from another (or any resource, for that matter) is known as kleptoparasitism, or parasitism by theft.

Whilst bears stealing the food of wolves is not unusual, hunting together is, The National Park Service told Insider, as the two species "usually ignore each other."

"Bears may benefit from the presence of wolves by taking carcasses that wolves have killed. 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."

The Parks Service added that grizzly bears and wolves have historically coexisted throughout a large portion of North America, with the majority of interactions involving food.

However, the wolves from Yellowstone national park have had more than their food stolen from them recently.

AP report that 20 wolves – roughly 17 percent of the grey wolves in Yellowstone – were killed by hunters in recent months.

A spokesperson from the park told AP that these kills are "a significant setback for the species' long-term viability and for wolf research."

This article was originally published by Business Insider.

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