Polar bear's epic nine day swim in search of sea ice

full article:

http://news.bbc.co.uk/earth/hi/earth_news/newsid_9369000/9369317.stm

snippets:

"This bear swam continuously for 232 hours and 687 km and through waters that were 2-6 degrees C," says research zoologist George M. Durner.

"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."

By fitting a GPS collar to a female bear, researchers were able to accurately plot its movements for two months as it sought out hunting grounds.

The scientists were able to determine when the bear was in the water by the collar data and a temperature logger implanted beneath the bear's skin.

The bears hunt their prey on frozen sea ice: a habitat that changes according to temperature.

"This dependency on sea ice potentially makes polar bears one of the most at-risk large mammals to climate change," says Mr Durner.