Beluga Whale

CLASS: Mammalia
ORDER: Cetacea
SUBORDER: Odontoceti
FAMILY: Monodontidae
GENUS: Delphinapterus
SPECIES: leucas

The beluga, a medium-size toothed whale, is white, a color adaptation to its environment - it lives primarily in the Arctic. Its white color is also the source of its name, which comes from the Russian word for white. Some scientists call this whale "belukha", to differentiate it from the beluga sturgeon (the fish from which we get caviar). Thick blubber makes it possible for the beluga to live in extremely cold water, and a back with no dorsal fin allows it to move freely under ice.

Physical Description

The beluga's body is thick, muscular, and tapered at both ends, with a small head and a narrow caudal peduncle (tail stock). Its head is rounded, and it has a short beak and a prominent, protruding forehead called the "melon". The beluga's neck is narrower than the necks of other whales, and it also differs from most whales — whose neck vertebrae are fused — in that its 7 neck vertebrae are free, which allows it to nod and turn its head.

Surface Characteristics

Color

Adult belugas are almost completely white. Calves are dark gray ; they become lighter in color with age and at full maturity they become white, though they retain some dark color on the edge of the flippers and flukes.

Fins and Fluke

Because it has no dorsal (back) fin the beluga can swim freely under floating ice. Instead of a fin it has a narrow ridge which runs down the rear half of its back. The ridge is sometimes notched, and may be a dark color. Its flippers are short, broad, and curled up at the tip in adults. The fluke is broad with a deep central notch.

Length and Weight

Adult males measure 5 meters (14-16 feet), with a maximum length of 5.3 meters (20 feet), and weigh about 3,300 pounds. Adult females measure 3.9-4.2 meters (13-14 feet), with a maximum length of 5.2 meters (17 feet), and weigh about 3,000 pounds. Females are considerably smaller than males on the Eastern side of the Atlantic.

Feeding

The beluga's diet is varied, and consists of small squid, crabs, clams, shrimp, sandworms, and various kinds of fish such as capelin, sandlance, and polar and arctic cod. It is especially fond of young salmon, and groups of belugas sometimes gather at the mouths of rivers to feed on the salmon as they return from their fresh water spawning grounds to the sea. A beluga consumes 50-60 pounds of food a day. It has about 10 conical shaped teeth on each side of its upper and lower jaw. Because it swallows its food whole, the beluga's teeth are not used for chewing, but for grasping and holding prey.

Mating and Breeding

Male belugas reach sexual maturity at 8-9 years, females at 5 years. Mating occurs in spring, and each summer many belugas migrate in great numbers to the comparatively warm, shallow waters of fresh water rivers to calve. In some places, like Svalbard, they are resident in coastal waters year round with no pattern to movements. Newborn calves are 1.4 meters (4-6 feet) long and weigh 110-130 pounds (50-60 kg). Gestation is about 14 months, and females bear calves every 2-3 years. The mother's milk, which is squirted into the mouth of the calf, is 30% fat.

Range Map

Distribution and Migration

Natural History

Among the most vocal of the cetaceans, the beluga produces a wide range of sounds that can be heard clearly on the surface of the water. We believe it creates sounds through its blowhole, which is located just ahead of the neck crease. Its squeaks, chirps, whistles, clicks, and other vocalizations can even be heard through the hulls of boats, and earned it the name "sea canary", which it was called by early whalers. It also produces a wide range of low and high frequency sounds that we cannot hear. . While these vocalizations have been documented in many locations, research shows some populations of belugas are relatively silent. The rounded melon on its head contains oil, and the whale can change the shape of the melon. Scientists believe that the melon plays a part in the beluga's echolocation system.

Status

Belugas have been hunted for centuries by native whalers for food, oil and "porpoise leather". They are still hunted by native people throughout most of the Arctic. Their natural enemies are orcas (killer whales), and in some areas, polar bears. Some belugas have been captured for display by oceanariums. Entrapment is ice is also a potential source of mortality. The current population is estimated to be 200,000 world-wide.

Bibliography

Perrin, W., B. Würsig, and J.G.M. Thewissen, Eds. Encyclopedia of Marine Mammals. New York, NY: Academic Press, 2002
Jefferson, T.A., M.A. Webber, R.L. Pitman. 2015. Marine Mammals of the World: A Comprehensive Guide to their Identification, 2nd edition. Elsevier/AP.

Acknowledgements

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