Conservation and wildlife
(WWF Statement via RedOrbit, 20 July 2011) -- As their icy Arctic habitat melts, polar bear mothers and their cubs are forced to swim long distances, which expose the cubs to higher mortality rates than cubs who do not have to swim as far, a study shows. “Climate change is pulling the sea ice out from under polar bears’ feet, forcing some to swim longer distances to find food and habitat,” co-author of the study, Geoff York of World Wildlife Fund (WWF), told Reuters. Polar bears are not naturally aquatic creatures. They rely on ice or land to hunt, feed and give birth, reports Reuters. Previous studies found that individual animals have had to swim hundreds of miles to reach ice platforms or land, but this is the first to show how these long swims expose polar bear cubs to greater risks. According to York, the current study is the first time these long swims have been quantitatively measured. Researchers used satellites to track 68 polar bear females equipped with GPS collars over a six year span, from 2004 to 2009. Data was gathered to find occasions when these bears swam for more than 30 miles at a time. Over those six years, there were 50 long-distance swims involving 20 bears, ranging up to 426 miles in distance, and with duration of about 12.7 days, according to the study presented at the International Bear Association Conference in Ottawa, Canada this week. At the start of the study when the bears were equipped with the GPS collars, 11 of the bears that swam long distances had young cubs. Five of the polar bear mothers lost their babies during the long swim, which represents a 45% mortality rate, report the study. For cubs that didn’t have to swim long distances with their mothers, the mortality rate was 18%.
Posted 24 July 2011; 4:10:36 PM. Permalink