A new video released by National Geographic shows a male polar bear pursuing a female and her young cub across the Arctic landscape, before killing the infant for food. While this footage is unique, the reality is that this type of event is nothing new or unusual, and polar bear cannibalism has been reported on numerous previous occasions by scientists studying the animals.
Despite being a top predator, polar bears are constantly at the mercy of the sea ice, which provides them with a platform for hunting seals. Seasonal fluctuations in sea ice levels therefore have a major impact on the ease with which the bears are able to access their prey. As such, the winter months tend to be the most fruitful in terms of hunting, although as the ice begins to thin during spring and summer, so too does the withering physique of the increasingly hungry bears.
With food resources running low beneath the midnight sun, male polar bears often turn to eating any cubs they come across, which represent their easiest source of nutrition. Because of this, mothers often have to be on the lookout for prowling males as they raise their young during the spring and summer.
The dramatic footage was captured by scientists aboard the National Geographic Explorer in Baffin Island, Canada, last summer. Appearing in the video, Ian Stirling of the University of Alberta explains that polar bear cannibalism could be on the rise as a result of climate change, which has been attributed with driving a reduction in sea ice levels, leaving polar bears with fewer hunting opportunities.
While this may well be the case, it is not accurate to state that climate change is the cause of this behavior as some news outlets have claimed as cannibalism has long been established as a natural element of polar bear conduct, and has also been observed in many other species.