“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.” -
Almost all cetaceans have a dorsal ﬁn, which acts as a surface to control attitude and prevent roll, yaw, and side-slip.
Among odontocetes, only right whale dolphins, the ﬁnless porpoise and both members of Monodontidae, the beluga or white whale and narwhal, lack a dorsal ﬁn.
Both beluga and narwhal possess, like finless porpoise, an irregular, notched dorsal ridge running along the caudal portion of the back, but the low (4–5 cm high) dorsal ridge of monodontids (also called a cuticular crest) appears insufﬁciently large to act as a suitable hydrodynamic control surface on these 4–5 m long odontocetes.
Researchers suggest that these fat pads, when elevated, form a pair of prominent vertical stabilizers that (perhaps in conjunction with the dorsal ridge) enhance an animal’s ability to control heading and limit roll.
Each year in July, hundreds of beluga whales congregate to mate and give birth in the mouth of the Cunningham River where warm, fresh water blends with the cold, salty arctic sea. During high tide they swim upstream with their backs barely covered by the shallow water, their stomachs rubbing the small rocks of the riverbed.