USGS Polar bears were tracked during long-distance swims in Arctic waters.
An innovative use of radio collars has allowed researchers to gauge the long-distance swimming skills of polar bears in the Arctic Ocean waters north of Alaska. The research, by United States Geological Survey biologists, shows that the predator has a truly formidable ability to routinely cover extraordinary distances in the water. The bear clearly earns its designation under federal law as a marine mammal.
The researchers tracked 52 females from 2004 to 2009 (I was told that the necks of male bears are too thick to accommodate radio collars), then compared the recorded tracks of the bears with maps of sea ice through the same period. The biologists documented 50 swims with an average length of 96 miles. The paper, “Long-distance swimming by polar bears (Ursus maritimus) of the southern Beaufort Sea during years of extensive open water,” is published in the Canadian Journal of Zoology.