Verified field observations show that the mighty blue whale (Balanenoptera musculus), Earth's largest creature, has resumed its historic migration off the western coast of the United States. After nearly being hunted to extinction by man, the legal protections afforded the endangered whale have benefited enough for it to resume some historic living patterns. It was thought that populations of blue whales off California were separate from those found in the eastern North Pacific. Researchers from the Cascadia Research Collective, NOAA, and Canada's Department of Fisheries and Oceans identified 15 individuals off British Columbia and in the Gulf of Alaska, four of which were previously seen off the California coast. Blue whales are identified by photographic comparison of skin pigmentation patterns and small fins on their dorsal side. Some populations have not rebounded after commercial hunting was stopped, such as those formerly found in the North Pacific.[photo courtesy Cornell U.]