Beluga, White whale, Sea Canary, Melonhead
The Beluga whale (Delphinapterus leucas) is a cetacean adapted to life 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. Belugas are commonly 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 highly sociable 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 cooperative animals and frequently hunt in coordinated groups. The animals in a pod are very sociable and often chase each other as if they are playing or fighting, and they often rub against each other. Often individuals will surface and dive together in a synchronized manner, in a behavior known as milling. 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.