It is an image that is sure to shock many people.

An adult polar bear is seen dragging the body of a cub that it has just killed across the Arctic sea ice.

Polar bears normally hunt seals but if these are not available, the big predators will seek out other sources of food - even their own kind.

The picture was taken by environmental photojournalist Jenny Ross in Olgastretet, a stretch of water in the Svalbard archipelago.

"This type of intraspecific predation has always occurred to some extent," she told BBC News.

"However, there are increasing numbers of observations of it occurring, particularly on land where polar bears are trapped ashore, completely food-deprived for extended periods of time due to the loss of sea ice as a result of climate change."

Story here.

Infanticide has tended to be more a means of bringing a female into a condition where she will be receptive to mating, and far less about food. But extreme habitat change, and resultant food shortages are obviously impacting on behaviour.

chairman bill wrote:Infanticide has tended to be more a means of bringing a female into a condition where she will be receptive to mating, and far less about food. But extreme habitat change, and resultant food shortages are obviously impacting on behaviour.

I think you are certainly correct when looking at animals that live in areas with abundant food, but in areas where there are severe food shortages the primary reason for infanticide could well be for food.

If your saw last nights Frozen World you would see the reason. When the bears come out of hibernation there is not enough time to hunt properly before the ice-flows melt. Summer is also lasting longer so the ice forms later causing once again a short hunting season before going back into hibernation.

I think there is a serious danger here of over-interpretation.

A few years back, there was an aerial survey of polar bears, in which just over 20 were found dead. Since this was the first such survey, the significance of this finding was moot. Nevertheless, a bunch of people, including reputable scientists, jumped to the conclusion that the bears had drowned due to melting ice leaving them stranded. That was before someone actually found out how incredibly far they could swim!

Polar bear infanticide, for all we know, might have been a regular feature of their behaviour going back thousands of years. Just not observed before. Not a good idea to jump to conclusions too enthusiastically. Such jumping may be under a low ceiling, resulting in concussion.

Lance wrote:I think there is a serious danger here of over-interpretation.

A few years back, there was an aerial survey of polar bears, in which just over 20 were found dead. Since this was the first such survey, the significance of this finding was moot. Nevertheless, a bunch of people, including reputable scientists, jumped to the conclusion that the bears had drowned due to melting ice leaving them stranded. That was before someone actually found out how incredibly far they could swim!

Polar bear infanticide, for all we know, might have been a regular feature of their behaviour going back thousands of years. Just not observed before. Not a good idea to jump to conclusions too enthusiastically. Such jumping may be under a low ceiling, resulting in concussion.

That must have been quite a few years ago, people have been aware that polar bears are effectively aquatic mammals for a very long time.