Polar bear, Ursus maritimus, which means “sea bear”. Male Polar Bear walking on the tundra. This bear has not had anything to eat for about 8 months. He is waiting for the ice to freeze on Hudson Bay so that he can hunt for Harp Seals. Adult male polar bears weigh from 775 to more than 1,500 pounds, 350 to more than 680 kilos. Polar Bears are endangered due to global warming. It is estimated that the Churchill population will be unviable in 30 years, and it is the largest single Polar bear population in the world.