Just how far can a polar bear swim?
Polar bears (Ursus maritimus) are capable of swimming incredible distances, according to a new study published in Zoology, which recorded polar bears regularly swimming over 30 miles (48 kilometers) and, in one case, as far as 220 miles (354 kilometers). The researchers believe the ability of polar bears to tackle such long-distance swims may help them survive as seasonal sea ice vanishes due to climate change.
"Summer sea ice conditions in the southern Beaufort Sea have changed considerably over the last 20 to 30 years, such that there is much more open water during summer and fall. Historically, there had not been enough open water for polar bears in this region to swim the long distances we observed in these recent summers of extreme sea ice retreat," explains co-author Karen Oakley, of the USGS Alaska Science Center.
Oakley and other scientists with the United States Geological Survey (USGS) used GPS collars to track 52 female bears from 2004 and 2009 recording 50 swims with an average of 96 miles (154 kilometers). The scientists even found evidence that cubs may be able to survive such swims as well. Out of ten observed polar bears with cubs, the scientists were able to find that six of them still had their cubs a year later.
Continues at Polar Bear.
Swimming Bear image by USGS.