Watch: Grizzly Bear Eats a Still-Live Cow Moose

At first, it’s hard to tell if the moose is still alive. The cow is in terrible condition, with a ragged coat and at least one broken leg. The cow’s feeble movements could be mistaken for the grizzly shaking what otherwise appears to be a carcass. But a wide-open eye and ribs that rise as she breathes are evidence that the moose is clinging to life, even as the bear goes to work.

Wyoming wildlife photographer Kevin Fuchs captured the images and posted it on his own Instagram profile this spring, along with a warning to viewers.

“This grizzly bear has been seen on this moose before which had previous injuries including a broken hind leg, if not both,” Fuchs writes in the video caption. He suspects the moose was hit by a car, resulting in the broken hind legs and an apparent inability to escape the bear.

Grizzly bears, like all other bear species, are omnivores. In addition to fresh meat, carrion, and insects, they eat roots, berries, herbs, and other vegetation. Their diet also changes depending on the ecosystem in which they live.

“[Their diet] “It varies greatly by region,” said Jamie Jonkel, a bear biologist with Montana Fish, Wildlife, and Parks Outdoor living in September. “Even here in Montana, there are different types of habitats. If you compare the Yellowstone ecosystem to the Missoula area, it’s totally different. If you go up north around Glacier [National Park] and Libby, it’s totally different. Then you go to the coast in Alaska, and it’s different. There’s a lot of variety there.”

Despite this variation, meat is a required food source in every part of a grizzly bear’s range. The world’s largest brown bears, the Kodiak brown bears, rely primarily on salmon and other fish for their diet. Grizzly bears in Montana and Wyoming eat a lot of ungulate meat, such as elk.

“Bears use the most nutritious parts of their food to maximize their weight gain,” the Alaska Department of Fish and Game explains in a information sheet about Kodiak bears. “Grasses and herbs are used only when they are growing rapidly in the spring and early summer. Brains, meat, and eggs are the favorite parts of salmon. Internal organs of deer, elk, and cattle are the first to be eaten when one is killed or eaten. Berries are used most often when they are ripe and the sugars are at their highest.”

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That could explain the behavior of this particular grizzly. Organs are the most nutritious part of a prey animal, so this bear could be feeding on hindquarter meat, or it could be eating the intestines and colon of the moose. (Wolves exhibit similar behavior while hunting and have even been known to pull fetuses out of the wombs of pregnant females or cows.) This video is a stark reminder that predators and prey alike will do whatever they can to survive.