Polar bears are unable to compensate for food loss in warming Arctic, says study

BBC : As global warming progresses, polar ice is melting and polar bears’ habitat is shrinking. Because of other bears’ ability to hibernate, during which their metabolic rates slow, researchers thought that polar bears might be able to do something similar during the summer months, as food becomes scarcer. To investigate the possibility of such “walking hibernation,” John Whiteman of the University of Wyoming and his colleagues attached satellite collars and implanted logging devices on some two dozen polar bears in the Beaufort Sea, north of Alaska. Although the researchers found that polar bears lack the ability to alter their metabolism in response to diminished food supplies, they do seem to have developed a unique ability to remain immersed in cold water for long periods of time. They do so by allowing the outer portion of their body to cool substantially and directing their body heat inward to protect their vital organs. However, that ability cannot compensate for the food loss associated with climate change, say the researchers.