Photographer Iain D. Williams was on assignment in the Canadian Arctic where he grabbed shots of a male polar bear killing and cannibalizing his cub.

He notes:

On one day we observed a male polar bear feeding upon what appeared to be some type of carrion – perhaps a seal or a other small animal.  However, upon closer inspection it was revealed that the small carcass was not a seal but rather a baby first year polar bear.  The location of the feeding male was given away by two ravens which could be seen from some distance jumping and flying about.

Circling the male was a female bear which appeared to be in obvious distress. The female was not walking as polar bears usually do – steadily and surely, but instead had a stiff gait and was walking erratically.  Further, the bear’s head was swaying from side to side and the mother was making low vocalisations.

Although cannibalism is not unheard of in the animal world, it isn’t commonly observed amongst polar bears.  There are several hypothesis for cannibalism, however, all are unfounded.  Perhaps the male bear is removing future competition by killing the cub, or is killing the cub to cause the female mother to become ‘available” again for mating.

Although these are plausible reasons, it’s more likely that the male bear was exceptionally hungry  and seized the opportunity for nutritional gain by feeding upon the cub. As mentioned earlier the bears are congregating to feed on ringed seals on the ice.  If the ice is not forming earlier enough, then the hungry bears become starved and after reaching such a poor condition may seek alternate prey such as young bear cubs or other animals.

Reuters adds a comment from Iain that explains that the image above of a polar bear carrying the head of the eaten cub is actually a female bear who came in to take the body away after a male polar bear had already eaten the body. Nonetheless, pretty disturbing photos.