A newly released video from National Geographic captures rarely seen polar bear cannibalism. The victim — a young cub — couldn't outrun the adult male that made a meal of it as its mother watched. (Warning: The video is graphic.)
This behavior has been studied (and even captured on video) before, and it probably happens more often than we'd like to think: Whenever seals become scarce or hard to hunt, as they do when ice disappears, male polar bears become desperate.
"This type of intraspecific predation has always occurred to some extent," Jenny Ross, who co-authored a study on a similar event she witnessed, told the BBC in 2011. "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."
Researchers have witnessed several less troubling signs of this desperation in recent years, including record-breaking dives in search of scant food and the hunting of species of dolphin that polar bears had previously ignored. But as impressive as it is that the 26,000 or so polar bears left on the planet are being resourceful, it's unlikely that this cobbling together of food sources will support the population.
“In the long term, the populations of these species of food for the polar bears are going to decline,” Peter Ewins, leader of Arctic conservation for the World Wide Fund for Nature, told National Geographic in September. “So it’s not going to be a persisting source of high fat for the polar bears.”
For now, there's no way of knowing for sure whether cannibalism is growing more common. We've certainly become more aware of it in recent years, but that might just be because of an increase in eco-tourism and research in the Arctic. But even if occasional cannibalism is a normal practice when food is scarce, the lean times caused by global warming are hardly going to help.