Last April US Geological Survey's biologists attached cameras and radio collars to four free-ranging female Alaskan polar bears. One of the resulting videos shows one of the bears in action in the Beaufort Sea, checking out a potential mate, swimming below ice, and trying to eat a frozen seal.
Female polar bears were used exclusively for the camera rigging; the necks of male polar bear males are wider than their heads, so collars easily slide off.
The full footage will be studied to improve understanding of polar bear behaviour amid continuing concern. Populations of these ferocious predators are generally believed to be at risk as a result of habitat decline as sea ice melts due to climate change.