[img=http://images.northrup.org/picture/xl/beluga/beluga-whale-smiling.jpg] > Belugas are also called white whales, and their unusual color makes them one of the most familiar and easily distinguishable of all the whales. Calves are born gray or even brown and only fade to white as they become sexually mature around five years of age. > White whales are smallish, ranging from 13 to 20 feet 4 to 6.1 meters in length. They have rounded foreheads and no dorsal fin. > Belugas generally live together in small groups known as pods. They are social animals and very vocal communicators that employ a diversified language of clicks, whistles, and clangs. Belugas can also mimic a variety of other sounds. > These whales are common in the Arctic Ocean's coastal waters, though they are found in subarctic waters as well. Arctic belugas migrate southward in large herds when the sea freezes over. Animals trapped by Arctic ice often die, and they are prey for polar bears, killer whales, and for Arctic people. They are hunted by indigenous people of the north, and by commercial fisheries that brought some populations, such as those in the Gulf of St. Lawrence, to near collapse. > Beluga feed on fish, crustaceans, and worms. The whale is related to the tusked "unicorn" whale known as the narwhal. The beluga is not related to the sturgeon of the same name, which has been heavily fished for its famous caviar.