Warning: the video below contains graphic footage.

A raw video that was taken during a National Geographic expedition on Canada's Baffin Island in the summer of 2015 shows the grizzly side of polar bears, as a large, fast male cannibalizes a young cub in front of his mother, the magazine reported. The gruesome phenomenon, which has long been known by people native to the Arctic, typically takes place in the late summer and autumn when seals, typical prey for polar bears, are less available due to their journey into the sea.

"One of the only things that's left to eat is, in fact, cubs of various ages," said Ian Stirling, a biologist at the University of Alberta. "The footage itself is quite rare, but the event probably isn't."

Given the larger, more aggressive nature of male polar bears, when times get tough, cannibalism is the easier route to take in comparison to making the search for food. Females, despite the fact that they can become even more starved than males while nursing their cubs, typically try to avoid conflict.

As shocking as this may seem, polar bears aren't the only animals that turn to the flesh of their own during hard times - hippopotamuses, tiger salamanders, sloth bears and numerous other species are known to participate in this behavior, according to the Daily Mail.

Some researchers claim that climate change may be to blame for this kind of behavior, pointing to the record-breaking number of dives that polar bears are taking in search of food that has become less and less abundant, NDTV reported, although others claim that there is no evidence yet to support this idea.

"In the long term, the populations of these species of food for the polar bears are going to decline," said Peter Ewins, leader of Arctic conservation for the World Wide Fund for Nature. "So it's not going to be a persisting source of high fat for the polar bears."