Associated Press: A conservation group filed today to protect Pacific walruses because of the threat to their northern habitat by global warming. The Center for Biological Diversity petitioned the U.S. Fish and Wildlife Service to list walruses as threatened under the Endangered Species Act because of warming and its effect on sea ice used by the animals as a feeding and resting platform. The group also said oil and gas development throughout the animals’ range was a threat. Bruce Woods, a …