Scientists track polar bear’s nine-day swim

Scientists working in the Arctic have tracked a polar bear that swam non-stop for nine days.

A team, from the US Geological Survey, followed the bear in 2008, as it left Alaska and swam

north to the sea ice. They published details of the remarkable feat in the journal ‘Polar

Biology’. Victoria Gill, reports.

Polar bears are superb swimmers. But their hunting ground is the surface of the Arctic ice,where resting seals make easy and calorie-rich prey. In the summer though, a swim between ice floes to catch seals can turn into a marathon.

The researchers fitted the female bear with a radio collar, and tracked her as she swam

continuously for nine days – the longest polar bear swim ever recorded. She covered almost

700 km in waters as cold as 2C. Then she hauled herself out of the water and travelled afurther 1,800 km – intermittently swimming and walking on the surface of the ice.

When the team recaptured the bear, she had lost almost a quarter of her body weight and her

year-old cub, which had been travelling alongside her, had disappeared.The scientists say that the

retreating Arctic ice could be forcing polar bears to take greaterrisks in search of food, embarking on ever more perilous long-distance journeys.

Victoria Gill, BBC News

Vocabulary and definition

superb	very good indeed
calorie-rich	full of calories, which provide energy
prey	animal which is being hunted by people or another animal
ice floes	large areas of ice which float on the sea
hauled	pulled or carried with great effort
intermittently	sometimes or occasionally
cub	here, young polar bear
retreating	here, melting ice
embarking	starting, beginning, or setting off
perilous	very dangerous

More on this story: http://news.bbc.co.uk/earth/hi/earth_news/newsid_9369000/9369317.stm

Read and listen to the story and the vocabulary online:

http://www.bbc.co.uk/worldservice/learningenglish/language/wordsinthenews/2011/01/110128_polar_swim_page.shtml