Common name: beluga, sea canary, white whale
HABITAT AND GEOGRAPHICAL DISTRIBUTION
Beluga, scientific name Delphinapterus leucas is an odontoceta cetacean of the family Monodontidae which lives in the arctic and subarctic waters along the coasts of Canada, Alaska, Greenland, Norway and the Soviet Union as well as at the mouth of the St. Lawrence River (the largest riverway in the world that crosses Québec and the main outlet of the Great Lakes, the largest expanse of freshwater in the world).
The habitat of the beluga is represented by the coastal areas, by the not too deep bottoms, by the mouths of large rivers where the waters are not very salty and not very deep, representing a safe refuge from predators and areas rich in nourishment suitable for childbirth, breastfeeding and the growth of children.
Belugas are mammals that have sexual dimorphism as the male is always larger than the female and among all the cetaceans they are the only ones that have 50% of their weight made up of fat (the average is 20%).
They have a tapered body at the ends with a small head and a not particularly large tail. The head of the beluga has a characteristic shape, with a very high and prominent forehead with the echolocalizer in the center (the same mechanism of sonar that uses the reflection of sound waves). It is able to change the shape of the head simply by blowing air. It does not have a large set of teeth but only 8-10 teeth on each side of the jaw which are used for grasping prey and not for chewing.
It is a close relative of the narwhal, belonging to the same family, but from which it differs due to the fact that its head and neck are very mobile (it does not have the vertebrae of the neck fused together), more than any other cetacean which allows it , when it emerges from the water to look around, moving its head in all directions, almost resembling a periscope.
The dorsal fin is absent and there is only a small ridge running along the back. This feature is important because it allows the beluga to be able to swim without problem under the ice without any dorsal fin causing it any problems. The pectoral fins have a particular shape and are inserted into the body in order to allow ample freedom of movement.
The characteristic is its white color (unique among dolphins) even if at birth it is black or dark brown. The typical color will be acquired within five years.
Their average speed is 9 to 10 km / h and they are capable of diving to enormous depths but they normally spend time on the surface.
CHARACTER, BEHAVIOR AND SOCIAL LIFE
The beluga is a social animal that lives in herds of thousands of individuals.
They are very playful and curious animals that have fun with whatever comes their way: a piece of wood, a plant, etc.
Since they live in the arctic areas to breathe, holes are created in the ice that are used precisely to put out the head to breathe.
In the summer months, a large number of belugas gather in estuaries or in any case where the seabed is low and rich in gravel where they rub themselves to eliminate the old, withered and yellowed skin of the previous year and thus return to the white and shiny skin.
COMMUNICATION AND PERCEPTION
It is an animal that emits numerous high frequency sounds as a result of its vocalizations are so loud that they seem like the sound of birds.
They are animals that also use body language a lot, such as moving their teeth or splashing around in water.
The beluga's diet consists of different varieties of fish: salmon, cod, but also invertebrates such as crab, shrimp, clams, worms, octopus, squid, etc.
Since they do not have a developed set of teeth, they also use suction to grab prey to trap them in their mouth and then swallow them whole. Consequently, the prey cannot be too large otherwise they would risk suffocating.
REPRODUCTION AND GROWTH OF THE SMALL
The way of reproducing is not well studied. Mating takes place towards the end of February - April and there is a whole ritual during which the males, to attract the females, make all kinds of noises moving in a disordered way in the water. When a female chooses the male to mate with, she places herself under his belly and they swim together in unison (see video below).
The pregnancy of the beluga lasts about 14 months at the end of which a dark colored puppy is born who is immediately able to swim (see video below).
The female has special muscles in the mammary gland that allow milk to be sprayed directly into the baby's mouth (see video below).
It is nursed until about 1.5 - 2 years of age. The relationship that is established between mother and child is very strong so that the puppy practically swims attached to the mother.
Sexual maturity is reached in females at 4 to 7 years while in males at 7 - 9 years.
The interval between one birth and another is 2 - 3 years.
The main predators of the beluga are killer whales and polar bears. Polar bears attack belugas in the same way they attack seals: by stalking at the holes dug in the ice that these animals need to breathe.
At one time these animals were also hunted by man to obtain meat but above all fat.
STATE OF THE POPULATION
Beluga is classified in the IUNC Red list (2009.1) as critically endangered animals of nature, CRITICALLY ENDANGERED (CR). It has been recognized that the population of this cetacean is reduced to a few hundred specimens with a very low birth rate (it has been estimated that the population has decreased by 75% in the last 26 years).
Not much is known about the life of the beluga and this fact is a further handicap that prevents groped to take measures to try not to extinguish this species. The main reason known was hunting, which over the years had caused severe population reductions. But for many years now, this threat has been averted, so scholars do not understand why the population of this cetacean continues to decline.
SOCIAL, ECONOMIC AND ECONOMIC IMPORTANCE IN THE ECOSYSTEM
In consideration of the fact that the beluga is an animal that eats enormous quantities of fish where it lives (also because it does not move alone but in numerous flocks), it is considered negatively by fishermen with whom it does not have a good relationship.
It is a very docile and intelligent animal and it is common to see it in water parks where it is a real attraction (see video above).
The Delphinapterus leucas is known by several names:beluga which derives from Russian byelukha which means "white, sea canary", so called by the old whalers for the fact that it emits a very vast series of whistles, yelps and screams that resemble a bird, "white whale" for its candid color.
Some scientists call this whale belukha to differentiate it from the sturgeonbeluga, the fish from which caviar is extracted.