Editor's note: Some viewers may find the images in this post disturbing.

While filming off the coast of Canada's Baffin Island, the crew of the National Geographic Explorer happened upon a scene rarely witnessed by humans: a male polar bear cannibalising a cub. The gruesome phenomenon has been studied since the '80s, but this newly released footage shows just how tough life in the Arctic can be.

Bear-on-bear predation events like this occur most frequently in late summer and autumn, something biologists like Ian Stirling chalk up to lack of food. During the summer months, local seal populations move offshore, leaving hungry male bears with few food choices. 

"One of the only things that’s left to eat is, in fact, cubs of various ages,” he told National Geographic. That said, the behaviour has also been witnessed in spring, a time when seal pups are abundant in the area. 

It might be tough to watch, but cannibalism and infanticide are common in the natural world. In some cases, like this pup-eating bull seal, the deed is driven by competition for a mate. Banded mongoose mothers kill any young born before their own, to ensure their babies receive ample protection from members of the mob (yes, a mongoose group is called a mob).

Scientists are unsure how climate change and retreating sea ice will affect cannibalistic behaviour in polar bears, but it's something Stirling and his colleagues hope to study in years to come. 


Top header image: foilistpeter, Flickr