Gray whales were called devil fish by early whalers because of their violent defensive behavior when harpooned or approached in close quarters. They now inhabit only the coastal waters of the eastern North Pacific and make one of the longest mammalian migrations on earth, traveling 10,000 B 14,000 miles annually from the Bering and Chukchi Seas in the north to their mating and calving lagoons in Baja California and Mexico. Mothers and calves stay together for about a year. Grays are baleen whales, feeding on plankton, squid and fish and are prey only to killer whales. A mature gray whale is 35 to 40 feet in length, weighs 35 tons, and has a life expectancy of 50 to 60 years. Eastern Pacific gray whales were removed from the Endangered Species Act list in 1994, and the stock has been increasing in recent years.