Delphinapterus leucas

Description

This whale's common name comes from the Russian word for "white," which is very appropriate since it is the only all-white whale in the world. Its genus name means "whale without fins," referring to the Beluga's lack of dorsal fins and short, rounded, wide flippers.

The beluga is one of the few cetaceans to have a well-defined neck and unfused neck vertebrae, meaning it can move its head in any direction. The head itself is melon-shaped, with a pronounced "beak."

One of the smaller members of whale order, the beluga averages 13-20 feet in length and weighs 2,975-3,300 pounds, with males being larger than females.

Distribution and Habitat

Belgua whales inhabit arctic and sub-arctic waters along the coast of Canada, Alaska, Greenland, Norway, and the Soviet Union. Their habitat includes inlets, fjords, channels, bays, and the shallow waters of the arctic seas that are warmed by continuous sunlight. They are also found at the mouths of rivers during summertime, where they feed, socialize, and deliver their offspring.

Diet

Belugas are opportunistic feeders, taking a variety of fish, marine molluscs, worms, octopus, squid, and other bottom dwelling creatures. Since their teeth are relatively small, belugas must use suction to trap prey in their mouths. They must also swallow their food whole, so prey size is limited by the size of the whale's throat.

Reproduction

The mating season runs from late February into early April. The males chase down the females, making all sorts of noises. The male throws down his tail and bends violently, then he throws his head up and down as his melon vibrates to ward off any other males who might attempt to mate with this female. Once a bond has been formed, the male and female swim in harmony and caress each other, until she swims underneath his belly. She puts her belly up against his and they continue to swim in harmony with each other. They mate only with absolute consent.

A single calf is born after a gestation of about 14 months. Births usually take place in estuaries because the water tends to be 10 or more degrees warmer, and are usually "attended" by a "midwife." The calf is about 5 feet long and grayish in color, and can swim almost immediately after birth. It is totally dependent on the mother's milk for a year, but lactation lasts 1.5 to 2 years.

It takes 4-7 years for females to sexually mature, 7-9 years for males. Females reproduce every 2-3 years, and stop reproducing in their early twenties. Life span in the wild is 32-40 years.

Other Behaviors

Belugas live in pods of 2-25 individuals. How pods come together is unknown, but age and sex seem to play some role. Several pods may come together during migrations, forming herds that can number into the hundreds or thousands.

Five to ten percent of a beluga's time is spent at the surface of the water. They are rarely seen breeching, although they will "bounce" vertically out of the water about one third of the body length. With an average maximum speed of about 6 miles per hour, belugas are fairly slow swimmers. They are, however, one of the very few whales capable of swimming backwards.

Belugas are constantly vocalizing and swimming around, over, and under each other. They also play with objects in the water, together or by themselves.

Considered one of the most vocal species of cetaceans, their voices sound like chirps, whistles, and squawks, which is why they are sometimes called "sea canaries." Belugas also use body language such as grinding their teeth or splashing around.

Scientific Classification

phylum Chordata
subphylum Vertebrata
class Mammalia
order Cetacea
suborder Odontoceti
family Monodontidae
genus & species Delphinapterus leucas

SOURCE
Animal Diversity Web animaldiversity.org/accounts/Delphinapterus_leucas/

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This page was last updated on September 22, 2017.