A male polar bear carries the head of a polar bear cub it killed and cannibalized in an area about 300...
A male polar bear carries the head of a polar bear cub it killed and cannibalized in an area about 300 km (186 miles) north of the Canadian town of Churchill in this picture taken November 20, 2009. Climate change has turned some polar bears into cannibals as global warming melts their Arctic ice hunting grounds, reducing the polar bear population, according to a U.S.-led global scientific study on the impacts of climate change. Picture taken November 20, 2009. REUTERS/Iain D. Williams (CANADA ANIMALS ENVIRONMENT IMAGES OF THE DAY) For best quality see GF2E63F03YF01