Beluga Whale

The beluga whale (Delphinapterus leucas ) is an Arctic and sub-Arctic cetacean. It is one of two members of the family Monodontidae, along with the narwhal, and the only member of the genus Delphinapterus. It is also known as the white whale, as it is the only cetacean to regularly occur with this color; the sea canary, due to its high-pitched calls; and the melonhead, though that more commonly refers to the melon-headed whale, which is an oceanic dolphin.

The beluga is adapted to live in the Arctic, with anatomical and physiological characteristics that differentiate it from other cetaceans. Amongst these are its all-white color and the absence of a dorsal fin, which allows it to swim under the ice with ease. It possesses a distinctive protuberance at the front of its head which houses an echolocation organ called the melon, which in this species is large and deformable. The beluga's body size is between that of a dolphin and a true whale, with males growing up to 5.5 m (18 ft) long and weighing up to 1,600 kg (3,530 lb). This whale has a stocky body. Like many cetaceans, a large percentage of its weight is blubber (subcutaneous fat). Its sense of hearing is highly developed and its echolocation allows it to move about and find breathing holes under sheet ice.

Belugas are gregarious and form groups of 10 animals on average, although during the summer, they can gather in the hundreds or even thousands in estuaries and shallow coastal areas. They are slow swimmers but can dive to 700 m (2,300 ft) below the surface. They are opportunistic feeders and their diets vary according to their locations and the season. The majority of belugas live in the Arctic Ocean and the seas and coasts around North America, Russia, and Greenland; their worldwide population is thought to number around 200,000. They are migratory and the majority of groups spend the winter around the Arctic ice cap; when the sea ice melts in summer, they move to warmer river estuaries and coastal areas. Some populations are sedentary and do not migrate over great distances during the year.

The native peoples of North America and Russia have hunted belugas for many centuries. They were also hunted by non-natives during the 19th century and part of the 20th century. Hunting of belugas is not controlled by the International Whaling Commission, and each country has developed its own regulations in different years. Currently, some Inuit in Canada and Greenland, Alaska Native groups, and Russians are allowed to hunt belugas for consumption as well as for sale, as aboriginal whaling is excluded from the International Whaling Commission 1986 moratorium on hunting. The numbers have dropped substantially in Russia and Greenland, but not in Alaska and Canada. Other threats include natural predators (polar bears and killer whales), contamination of rivers (as with Polychlorinated biphenyl (PCBs) which bioaccumulate up the food chain), climate change, and infectious diseases. The beluga was placed on the International Union for Conservation of Nature's Red List in 2008 as being "near threatened"; the subpopulation from the Cook Inlet in Alaska, however, is considered critically endangered and is under the protection of the United States Endangered Species Act. Of all seven extant Canadian beluga populations, those inhabiting eastern Hudson Bay, Ungava Bay, and the St. Lawrence River are listed as endangered.

Belugas are one of the most commonly kept cetaceans in captivity and are housed in aquariums, dolphinariums, and wildlife parks in North America, Europe, and Asia. They are considered charismatic because of their smiling appearance, communicative nature, and supple graceful movement.

The beluga is also called the white whale because of its milky white skin and is the only whale species that is completely white. It is gray when born and this color fades gradually with age. It is small in size and lacks a dorsal fin. Belugas are toothed whales, with flexible lips that can produce a range of facial expressions. They have wide, paddle-like flippers and notches in their tails. Their necks are extremely flexible and they can turn their heads almost 90 degrees sideways. Their extremely thick layer of blubber provides insulation in freezing Arctic waters. Their bodies are fifty percent fat, much higher than other non-Arctic whales, with a body fat of only twenty percent.

Beluga whales occur in the Arctic and sub-Arctic waters of the Arctic Ocean. During the summer, they can mainly be found in deep waters, particularly along the coasts of Alaska, northern Canada, western Greenland, and northern Russia. The southernmost extent of their range includes isolated populations in the St. Lawrence River in the Atlantic, the Amur River delta, the Shantar Islands, and the waters surrounding Sakhalin Island in the Sea of Okhotsk. Belugas are migratory and the majority of groups spend the winter around the Arctic ice cap; when the sea ice melts in summer, they move to warmer river estuaries and coastal areas. Some populations are sedentary and do not migrate over great distances during the year. coastal areas, as well as the adjoining seas, preferring inlets, fjords, bays, channels, and the shallow Arctic waters warmed by continuous sunlight.

Beluga whales are diurnal and very social animals. During summer, thousands of them gather together in river estuaries to molt. They rub their bodies on the gravel of the sea bed to shed their yellow, withered skin from the previous year and to again become gleaming white. At this time, females with babies will often group together, while males gather in large bachelor groups. Belugas are able to dive deeper than 1,000 m, but usually, they are found on the surface, swimming slowly. During winter it may become necessary to form breathing holes amongst the ice, which they do with their heavy heads. Belugas are among the most vocal cetaceans. They use their vocalizations for echolocation, during mating, and for communication. They possess a large repertoire, emitting up to 11 different sounds, such as cackles, whistles, trills, and squawks.

Belugas are carnivores (piscivores, molluscivores) and eat a variety of prey, such as smelt, flatfish, flounder, salmon, sculpins, and cod. They also eat invertebrates such as crabs, clams, shrimps, worms, octopuses, squid, and more creatures that live on the seabed.

Beluga whales are polygynous, with a dominant male often mating with several females during one mating season. The mating season takes place between late February and early April. Gestation lasts 14 months and a single calf is produced. The calf has a grayish color and is very well-developed. The nursery pod stays together during the delivery, then all of them move off except for a teenage nursemaid. Birthing usually takes place near rivers because the temperature of the water is ten degrees higher there. This is for the benefit of the calf, which has less blubber than a full-grown adult. The newborn stays between the two females, their swimming pulling him along with the current. A calf totally depends on its mother’s milk for one year, and lactation lasts as long as 1.5 to 2 years. Females become reproductively mature in 4 to 7 years and males in 7 to 9 years of age.

Hunting by Inuit and Alaska Native groups is the biggest known threat to belugas across certain portions of their range. Further threats are contamination of river estuaries, infectious diseases, and disturbance by vessel transport, gas, and oil production. An increasing concern is noise, which can damage a whale’s hearing and affect its ability to navigate, communicate, and locate prey.

According to the IUCN Red List, the total size of the beluga whale population is 136,000 mature individuals. Currently, this species is classified as Least Concern (LC) on the IUCN Red List.

    Fun Facts

• Beluga whale offspring return to places where they have been with their mothers, who they remember and bond with year after year.
• Belugas are called "canaries of the sea," due to the vast range of sounds they produce, including whistles, squeals, moos, clicks, and chirps. Besides vocal communication they also communicate by means of rubbing or bumping against each other, chasing each other, and playing games.
• Beluga whales' dives can go as deep as 800 meters and may be for up to 25 minutes.
• The word "beluga" is from the Russian "bielo" meaning "white".
• Belugas can swim backward.
• Belugas can alter the shape of their forehead, known as a "melon", by means of blowing air around their sinuses.
• Belugas are able to see within and outside of water, but their vision is relatively poor when compared to dolphins.