A female polar bear recently swam over 400 miles in water barely above freezing, apparently in search of ice that had not been melted by climate change. It's a tale that's equal parts insane, tragic, and completely terrifying.
The bear was being tracked with a GPS collar by researchers from the US Geological Survey. Zoologist George M. Durner explains the bear's remarkable trek:
"This bear swam continuously for 232 hours and 687 km and through waters that were 2-6 degrees C. We are in awe that an animal that spends most of its time on the surface of sea ice could swim constantly for so long in water so cold. It is truly an amazing feat."
Polar bears are known to swim, but never over distances or times as great as this. By tracking this particular bear's journey, we now know just how far bears can travel across open water...although it isn't without its consequences. The bear lost more than a fifth of her body fat in two months as a result of this journey, and her yearling cub was unable to survive the trip. Whatever this trip was, it definitely wasn't a pleasure cruise.
Indeed, Durner suspects these journeys would have been unnecessary in previous years, when there were enough pockets of free ice during summer months to keep travel times short:
"In prior decades, before 1995, low-concentration sea ice persisted during summers over the continental shelf in the Beaufort Sea. This means that the distances, and costs to bears, to swim between isolated ice floes or between sea ice and land was relatively small. The extensive summer melt that appears to be typical now in the Beaufort Sea has likely increased the cost of swimming by polar bears. his dependency on sea ice potentially makes polar bears one of the most at-risk large mammals to climate change."
We've learned that polar bears are even more powerful than we could have possibly imagined, but it still may not be enough to save them if climate change keeps melting the summer ice. Still, humanity better keep this in mind if we don't move on climate change - even an entire ocean won't protect you from a pissed off polar bear.
[via BBC News]