Environmental stresses reducing size of polar bears
By Victoria Gill, Science reporter, BBC News Polar bears have shrunk over the last century, according to research. Scientists compared bear skulls from the early 20th Century with those from the latter half of the century. Their study, in the Journal of Zoology, describes changes in size and shape that could be linked an increase in pollution and the reduction in sea ice. Physical “stress” caused by pollutants in the bears’ bodies, and the increased effort needed to find food, could limit the animals’ growth, the team said. The researchers used the skulls as indicators of body size. The skulls from the later period were between two and 9% smaller. “Because the ice is melting, the bears have to use much more energy to hunt their prey,” explained Cino Pertoldi, professor of biology from Aarhus University and the Polish Academy of Science, and lead scientist in this study. … “We also know from previous studies that some chlorinated chemical pollutants have affected the fertility of the females,” he continued. … He said: “Polar bears are one of the most polluted mammals on the globe.” …
