Greenland whale description. The bowhead whale is the mammal with the longest life expectancy
In the seas and oceans of our planet there are truly gigantic mammals - whales. There is a scientific theory that they once descended into the ocean from the earth’s surface: this is evidenced by the structural features of these huge animals. And they are really huge and majestic. Thus, the bowhead whale, which will be discussed in our article, holds a confident third place in the imaginary championship of the largest living creatures on Earth (after the fin whale and the blue whale, whose weight can reach just under 200 tons). By the way, it is believed that it was he who served as the prototype for the famous character Miracle Yudo, the fish-whale, described in folk and literary fairy tales.
Main characteristics
Compared to its more powerful brothers, the bowhead whale is a mere crumb. Its weight can reach as little as 100 tons, although no one has yet had complete success in weighing a living adult animal. Thus, the mass of the bowhead whale, elephant, and rhinoceros (the heaviest land animals) is not entirely comparable. After all, an adult African elephant, for example, reaches a weight of only 6 tons, and a rhinoceros - even less (old males, according to researchers, do not exceed 5 tons in weight).
The maximum length of a whale is up to 22 meters (average - 18). Adults can dive to depths of more than 200 meters and remain without air for 40-60 minutes. Average travel speed is 20 km/h. The average life expectancy is about 40 years. However, according to scientists, some individuals can reach a very advanced age - up to 200 years. Accurate information is quite difficult to obtain due to poor knowledge of these mammals (observation is difficult due to the harsh habitat).
Appearance and habitat
The bowhead whale does not have a dorsal fin. It is also distinguished by a huge head (about a third of the entire body), a rounded body structure, and a wide caudal fin. This animal has the largest baleen - up to 5 meters. Almost all individuals have 2 humps clearly visible in their profile. The animal's subcutaneous fat reaches a thickness of 70 centimeters, which allows it to easily endure the cold. And the bowhead whale lives in the Bering, Chukchi, Barents seas, inhabits the North Atlantic and the Pacific Ocean in the northern part. The southernmost population is located in the Sea of Okhotsk. These mustachioed giants spend their entire lives in polar waters (hence the name - bowhead polar whale), constantly migrating: in the fall - to the south, in the spring - to the north, moving away from the ice. Sometimes a herd of whales walks, breaking ice up to 20 cm thick, like icebreakers, clearing their way.
Nutrition
Such a large mammal is conventionally classified as a predator: the bowhead whale feeds only on plankton (calanus crustaceans and pteropods). And the amount of food consumed per day is simply amazing - about 2 tons. The feeding method is typical for representatives of baleen whales. While eating, animals move through the water column with their mouths open. In this case, plankton settles on the baleen plates, of which the whale has many, and is removed with the tongue, after which it is swallowed. Whalebone is thin, which allows it to filter out especially small crustaceans.
Reproduction
The bowhead whale is a mammal. The female carries the calf for more than a year, then the calf is born (in April-June). A caring mother pushes the baby to the surface so that he can breathe air, otherwise he may choke. The length of a small whale is up to 4 meters. And it is born with a fully formed layer of fat, which provides thermal insulation in cold waters. The mother feeds the baby milk for up to six months, and then it switches to autonomous feeding on plankton.
People and whales
Due to its impressiveness and huge dimensions, this mammal has practically no natural enemies. The exception is killer whales, which occasionally attack sea giants (in schools of up to 30 individuals per whale). The main enemy of this animal is man. Hunting bowhead whales has long become a habit. By the way, it is not so difficult to catch up with the giant - this creature is slow and clumsy, although it is not without some grace. Typically, in earlier times, whales were caught using spears and hand harpoons, and rowing boats were used as vessels. A killed whale does not drown in water, which also makes hunting much easier.
Red Book
It got to the point that in the 17th century, up to 1,000 ships came to Spitsbergen, the habitat of the populations, trying to catch the bowhead whale. And in the 18th century, the annual production was 2,500 individuals. By the 20th century, this led to the fact that, for example, in the Barents Sea, these mammals were considered completely exterminated. And in 1935, a ban was established on the hunting of such an animal as the bowhead whale. The Red Book also includes this giant mammal as an endangered species. And the modern whale population numbers only up to 10 thousand individuals.
The bowhead (polar) whale is a representative of the suborder of toothless whales. Another name for this suborder is baleen whales. belongs to the genus of the same name and forms a separate species.
Bowhead whale: facts
About 200 years ago, this mammal was found throughout the Arctic Ocean. Today their numbers have noticeably decreased. Now it can be found in the Chukchi, Bering and East Siberian seas, rarely in the Beaufort Sea. In the western Arctic Ocean it is found in the northern part of the Barents Sea and near Franz Josef Land and Spitsbergen. Very rarely swims into the waters adjacent to Jan Mayen Island. It usually swims and searches for food in surface waters; it tries not to dive to depths, although it dives well to depths of up to 300 meters.
The body of this mammal reaches 21 meters in length. But this is an indicator for a male, females are smaller, their body reaches 18 meters in length. The body weight of the bowhead whale varies from 70 to 110 tons.
Its weight depends on nutrition and season. The whale has a large head; it is one-third the size of the body. Between the head and the body there is a semblance of a neck. The bowhead whale's oral cavity is arched and located high. This is due to the fact that the upper jaw is much smaller than the lower jaw.
The bowhead whale does not have a dorsal fin. But it has a powerful tail and side fins. The mammal's small eyes are located near the corners of the mouth. The oral cavity is large, filled with flexible vertical plates of whalebone. These plates reach 4.5 meters in length. Each of them has a fringe. The number of these plates reaches four hundred. The bowhead whale's body is usually dark gray in color. The body of some individuals may be dark blue or black. The neck, lower jaw, and often the belly are light in color. The sei whale looks completely different.
Bowhead whale: behavior and nutrition
The basis of the diet is plankton, namely: fish larvae and eggs, small crustaceans, and pteropods. This mammal eats approximately 2000 kg of this food per day. The whale swims at speeds of up to 15 km/hour. often makes jumps. This is a very interesting sight: a huge mammal emerges halfway out of the water and then falls to the side.
The bowhead whale is constantly in a state of migration. In summer, it swims to cold northern waters and returns to coastal waters in winter. The ice on its path does not create obstacles; the animal easily breaks the ice, the thickness of which can reach 20 cm. Whales migrate in an organized manner, the school forms a wedge and swims. Such organization increases the efficiency of hunting. Arriving at the place, the group breaks up. Some of the animals lead a solitary lifestyle, some individuals can gather in small flocks. The whale breathes very interestingly: to clear its lungs of nitrogen, it releases fountains of water into the air. It prefers to sleep almost on the very surface of the water.
Greenland polar whale: reproduction and life expectancy
In early spring, whales migrate to northern waters. It is there, in cold water, that females give birth to their young. This occurs from April to July. The body of a newborn reaches a length of 4-5 meters, but how much it weighs at birth is not known. The female feeds the cub with milk for 6 months. These whales have not yet been studied enough. They live in harsh conditions in the Far North. Most of their life is spent in ice, which makes them very difficult to study. There is an opinion among scientists that there are two species of whale living in the Arctic Ocean, and not one, but this theory requires proof.
The mating season occurs at the same time of year as childbirth. The bowhead whale's gestation period is about 13 months. Females can give birth to offspring once every 3 years. Therefore, at the same time, some females give birth, while others only mate. A newborn whale has a lighter color than its parents. At the age of one year the skin darkens. The bowhead whale lives for about 40 years, although some experts suggest that its actual lifespan is 100 years. However, this point of view has no evidence.
Enemies of the bowhead whale
Thanks to its dimensions has almost no enemies in the vast expanses of the Arctic Ocean. They are not afraid of him either. Only killer whales, whose second name is killer whales, are dangerous for them. They often attack bowhead whales and other marine mammals, but the damage they cause is much less than the damage to humans. People shot these mammals en masse and their population today is negligible. Now the bowhead whale, see photo below? included in the International Red Book. Fishing for this mammal is prohibited.
Order - Cetaceans / Suborder - Toothless whales / Family - Right whales / Genus - Bowhead whales
History of the study
The bowhead whale, or polar whale (lat. Balaena mysticetus) is a marine mammal of the baleen whale suborder. The only species of the genus of bowhead whales (Balaena).
Spreading
Polar whales are common in the eastern part of the Bering Sea, the Chukchi Sea, off the coast of Alaska, and in the Beaufort Sea. In the North Atlantic they inhabit Davis Strait, Lancaster Strait, the waters of Iceland, Jan Mayen, the Greenland Sea, the waters of Spitsbergen and the western part of the Barents Sea. We are found in the Pacific Ocean basin, in the northern part of the Bering Sea, the Gulf of Anadyr, the Bering Strait, the Chukchi Sea, and possibly in the East Siberian Sea. In the Atlantic Ocean basin - in the northern part of the Barents Sea, near Novaya Zemlya, Murman and Vaygach Island. The bowhead whale usually stays in the surface layers of water, in the coastal part of the seas. Searches for food most often along the edge of the ice or between scattered drifting ice floes.
Appearance
The bowhead whale belongs to the family of right whales, which have no stripes on their bellies. The body length of the bowhead whale is 14-18 m. Even with such a long length, the whale appears fat and clumsy due to the very large cross-section of the body. Weight on average 44-58 tons, depending on the time of year and fatness. The fat layer reliably protects the bowhead whale from the cold of the Arctic seas and serves as a reserve for the winter, when food becomes scarce. The body is massive, short, very thick, without a dorsal fin. The huge head is a third of the body length and is separated from the body by a noticeable neck band. The cut line of the mouth is curved upward in the form of a smooth arc. The lower jaw is massive, bucket-shaped, much larger than the upper. The eyes are very small, located low, near the corners of the mouth. The ear openings open behind and slightly below the eyes.
Huge curved mouth. Narrow snout. A sharply defined depression behind the respiratory opening. The head occupies a third of the entire length. Rounded back. Wide divided nostrils. Large stocky body. The black, blue-black, dark gray, or dark brown body is mottled with grayish spots. A pale gray or white patch extends around the thin part of the caudal peduncle (in individual cases). Wide oar-shaped fins. Pointed ends of caudal fins. Slightly concave tail edge. Distinct notch in the middle. The filtering apparatus contains 230-390 pairs of black long narrow plates up to 4.5 m high with soft fringe. The breathing hole is paired. The pectoral fins are large. Wide caudal fins can reach almost half the entire body length. The tail may have a white upper edge.
Reproduction
Mating of individuals of this species occurs in spring or early summer. The female's pregnancy lasts approximately 13 months, so the offspring are born in April-June of the following year. The length of a newborn whale is approximately 4 meters. Feeding with milk is carried out for six months, after which the young animals switch to a natural diet. The female usually gives birth to her next litter three years after giving birth.
Lifestyle
Bowhead whales occasionally jump out of the water, raise their tails, flapping their fins, and make reconnaissance jumps (usually single). It usually rises vertically from the water, with the back of the body usually remaining below the surface and falling to one side. Most of the jumps can be seen during spring migrations. Young animals may play with objects in the water. They feed either below the surface, or perhaps throughout the entire water column - moving slowly towards the surface with an open mouth. Animals sometimes feed in groups.
In the summer months, bowhead whales do not form aggregations; they are usually observed alone and less often in small groups (up to 5 animals). It gathers in herds only during migrations or on large accumulations of food. Bowhead whales undergo seasonal migrations, the timing of which is largely determined by the location and timing of movement of the Arctic ice edge. The wounded can remain under water for up to 60 minutes. When calm, it swims at a speed of 7.4 km/h, and when wounded, it swims at up to 16.7 km/h.
Typically spend 1 to 3 minutes on the surface, releasing 4 to 6 fountains. The fountain is condensed steam. Along with the fountain, foam is thrown out, which consists of a fatty emulsion. It absorbs excess nitrogen that accumulates in the animal's lungs. Can dive to depths of more than 250 m; average dive time is 4 to 20 minutes, but deeper dives are known.
They usually emerge in the same place. The fountain, widely divided by a blowhole, is V-shaped and exhales to a height of up to 7 m. The giant tail, more than 7 m in diameter, usually rises vertically into the air before diving deeply. Sometimes sleeping whales were observed when they lay motionless for a long time at the surface of the sea.
Whales form three local herds: Bering-Chukchi, Spitsbergen and West Greenland. The whales of the first of these pods winter in the northern and eastern parts of the Bering Sea. In the spring, they go through the Bering Strait into the Chukchi Sea, where most of them turn to the shores of Alaska in the Beaufort Sea, to Amundsen Gulf, and the other part goes to Wrangel and Herald Islands. Here they spend the summer and return to the Bering Sea in the fall.
The Svalbard herd apparently winters east of southern Greenland. In the spring, whales move to Iceland and Jan Mayen and then to Spitsbergen. In summer, most of the whales swim to the eastern shores of Greenland, and a smaller part - to the northern part of the Barents Sea, from where in past years, when the whales were more numerous, they entered the Kara Sea. In autumn, whales migrate south along the eastern shores of Greenland. The West Greenland whales spend the winter at the edge of the ice somewhat south of Davis Strait and Hudson Bay, and spend the summer in the Lancaster Strait and some other straits of the Canadian archipelago, in Baffin Bay. It is unknown whether these populations interbreed.
Habitat is associated with floating ice (usually where ice cover is 70%). Short seasonal migrations are associated with the formation and movement of ice (northern in summer, southern in winter). Living in the ice zone is common for them, because bowhead whales are able to cross an area of dense drifting ice hundreds of kilometers long, using minor openings and openings.
Nutrition
Bowhead whales feed exclusively on plankton, mainly consisting of crustaceans (mainly Calanus finmarchicus, as well as pteropods Limacina helicina). An adult bowhead whale can consume up to 1.8 tons of food daily.
Bowhead whales feed in a manner typical of all representatives of baleen whales. About 325-360 baleen plates up to 4.3 meters long hang from each side of the whale's mouth. While feeding, the whale moves through the water with its mouth open. In this case, planktonic crustaceans settled on the baleen plates are scraped off with the tongue and swallowed. A characteristic feature of the baleen of bowhead whales is its unusually thin structure, which allows the animal to filter out crustaceans that, due to their size, are inaccessible to other whales.
Number
Before the start of active fishing in the 17th century, the world population of bowhead whales was so numerous that, according to the captain of a ship sailing to Spitsbergen, his ship “had to push aside the herds of monsters frolicking in the water, as if it were pack ice.”
However, by the end of the 19th century, whaling brought this species to the brink of destruction. Dutch whalers alone killed at least 50 thousand individuals in the Spitsbergen area.
In 1935, the International Whaling Commission established a ban on the harvest of the bowhead whale, and the ban was subsequently confirmed several times. Since 1973, this whale has been included in Appendix I of the CITES Convention.
The modern population of bowhead whales, estimated at at least 10 thousand individuals, is mainly concentrated in the Chukchi, Bering and Beaufort seas.
Bowhead whale and man
Hunting the bowhead whale is the pinnacle of the unique marine hunting culture of the Eskimos and coastal Chukchi. For thousands of years, they successfully harvested these animals from leather kayaks using ingenious rotating harpoons made of bone and stone. There is a lot of evidence of this hunt in archaeological finds of the first centuries of the new era - these are the remains of whale harpoons, killing spears, cutting knives, rock paintings depicting scenes of whale hunting. Thousands of whale bones have been discovered in the ruins of ancient settlements on the coast from Uelkal to Cape Schmidt. They were used as the main building material in the construction of housing, pits for storing meat, kayak dryers, and grave treasures. Only at the ancient sanctuary on Yttyrgan Island in the Senyavin Strait were the skulls of 60 bowhead whales found.
The bowhead whale is a mammal belonging to the order Cetaceans, the family Right Whales. In Latin it is called Balaena mysticetus. There was a time when populations of these animals lived in the ocean spaces of the entire Northern Hemisphere.
However, today they are found only in the Bering Sea and in the area of the Spitsbergen archipelago, Davis Strait and Hudson Bay. According to scientists, the total number of these mammals does not exceed 10,000 individuals.
The bowhead whale is second in size only to the vomit whale. Its length can exceed 20 m, of which the head accounts for a third. Weight can reach up to 130 tons. Interestingly, females are larger than males. The color is predominantly dark, with only a large white spot under the lower jaw.
The structure of the oral cavity is specific, associated with the way of nutrition. On the curved jaws there are numerous plates (up to 400 pieces) more than 4 m high and less than 0.3 m wide, called baleen. The bowhead whale feeds on plankton and small fish. When getting food, it swims with its mouth open. Everything that gets into the plate is retained on the plates, scraped off with the tongue and swallowed. The weight of food eaten daily is estimated at 1.8 tons.
Its pectoral fins are shortened, widened, and rounded. The bowhead whale has smooth skin. The photos presented in the article demonstrate the absence of horny growths and attached crustaceans. Subcutaneous fat in an adult is approximately 70 cm. It is very important, because it neutralizes excess during immersion and protects against hypothermia. Their body temperature is normally the same as that of humans (they are also mammals). The eyes are small with a thickened cornea. They are protected from the effects of salt water by special glands that secrete an oil-containing liquid. Vision in water is poor, better on the surface.
The bowhead whale is capable of diving to a depth of 0.2 km and emerging after 40 minutes. The time spent under water depends on the amount of air in the lungs. His nostrils are located on the top of the head, they open only at the moment of inhalation and exhalation, the muscles of the nasal canal prevent water from entering the lungs. The whale begins to exhale at the surface of the water, the result of which is a fountain, the height of which can exceed 10 m. The need to inhale air forces these mammals to break through the ice thickness of 25 cm.
There is no auricle, but hearing is very well developed. perceives both sound and ultrasonic vibrations. The range of sounds produced is wide. The bowhead whale has a sonar that allows it to navigate well in the ocean. The time between the sound produced and its return indicates to the animal the distance to a certain object along the way.
Sometimes a polar whale (this is also the name of this giant) jumps out of the water, slaps its fins on its body and sinks onto one of its sides. Such attractions occur during migration and mating season.
Reproduction is not well understood, although pregnancy is known to last approximately 13 months. The cub is born 4 meters tall. For a year he feeds on his mother's milk. Whales become sexually mature at 20 years of age. They live on average 40 years.
Order: Cetaceans Family: Right whales Genus: Bowhead whales (Balaena Linnaeus, 1758) Species: Bowhead whale Rarity category: 1 - for the endangered North Atlantic and Sea of Okhotsk populations, 3 - for the rare Bering-Chukchi population.
Scientific name - Balaena mysticetus Linnaeus, 1758
Bowhead (polar) whale- Balaena mysticetus Linnaeus, 1758
Spreading: In the past, the bowhead whale was numerous both in the west and in the east. sectors of the Arctic, found in the area of drifting ice in the Greenland, Norwegian, Barents, Kara, East Siberian, Chukotka, Bering, Okhotsk, as well as Beaufort seas and along the Canadian arch. . In the circumpolar range there were 5 geographical, but not taxonomically isolated herds, of which 3 herds (Svalbard, Bering-Chukchi and Sea of Okhotsk) migrated within the Russian seas.
Habitat: An inhabitant of arctic and subarctic waters, it usually stays near the edge of floating ice. Capable of breaking ice up to 22 cm thick. The food of bowhead whales is the massive crustaceans - Calanus and Tizanoessa, which are caught at depths of about 50 m. Herds of up to several dozen animals gather in the feeding fields and during the rut. The maximum duration of diving is 85 minutes, the average is 15-17 minutes, females with cubs dive for 6-7 minutes. During spring migration they usually travel alone.
In the Chukchi Sea, near Herald Bank, groups of 50-70 animals were observed, in the Beaufort Sea, near Cape Barrow, a cluster of 56 animals was observed, and a group of 14 polar whales was photographed here on September 14, 1982. Body length at birth is 4-4.5 m, by the year it increases to 8.2 m, by puberty - up to 14 m and in physically mature individuals - up to 20 m. Sexual activity from March to May; pregnancy 13 months, birth from March to August, with a maximum in May. The lactation period is about a year. Pregnant females make up 15% of mature females. Life expectancy, judging by harpoons extracted from the body of whales, reaches 40 years.
Number: The total number before the start of fishing in the 17th century. approximately reached 50 thousand individuals. Under the influence of intensive fishing already in the 17th century. The number of the Spitsbergen herd decreased critically; in the 18th century. - West Greenland and Hudson herds, in the 19th century. - Bering-Chukchi and Sea of Okhotsk herds.
Extermination led to a widening gap between populations. The state of the numbers of different populations at the present time. time is not the same. The Svalbard, or North Atlantic, herd of bowhead whales is on the verge of complete extinction and requires urgent additional measures of protection and intensification of environmental research. The initial size of the herd reached 25 thousand at the present time. In time, perhaps only a few dozen whales have survived.
Only single individuals are found in the Barents Sea. The range of the herd has a seasonal pulsation: in the summer it sows. the border shifts to the high latitudes of the Arctic, to the zone of polar drifting ice (northern Spitsbergen, Franz Josef Land and Novaya Zemlya), and in winter, with the advance of ice from the north and south. the border shifts in the south, to the islands of Newfoundland, Iceland, Jan Mayen, and to the waters of the Barents and Kara Seas. The Bering-Chukchi herd of bowhead whales is showing a recovery trend.
In accordance with the decision of the International Whaling Commission, since 1998, the small indigenous peoples of Chukotka are allowed to catch up to 5 whales per year for traditional needs. In the middle of the 19th century. it numbered from 11.7 to 40 thousand individuals. Currently The number of whales is increasing over time. So, back in 1980, there were only 1500-3000 heads in this herd, according to other sources, in the west. 1,500 individuals lived in parts of the Chukchi Sea, and 3,000 individuals lived in the Beaufort Sea.
Currently At the time, the total number of bowhead whales in the Bering Sea, including the Chukchi and Beaufort Seas, reaches 6-9 thousand, with a possible 3% increase in the population per year. After wintering in the north. and east In parts of the Bering Sea, whales in the spring, following the ice, enter the Chukchi Sea, and one part moves to the Wrangel and Herald Islands, and the other into the Beaufort Sea, to the bay. Amundsen. By winter, whales again descend into the Bering Sea and Anadyr Bay. .
The southernmost entry into the hall is marked for the view. Osaka (33°29" N), where on June 29, 1969, a 6.4 m long calf was caught in a net. The Sea of Okhotsk herd of bowhead whales is in a threatened state and is still very poorly studied. Nothing is known about its migrations. Fishing in the 19th century The century was carried out mainly in the western, middle and northern parts of the Sea of Okhotsk from the Shantar Bay to the Penezhin Bay.
By the beginning of the 20th century. the population was on the verge of extinction. By the beginning of mass fishing (19th century), the number of this herd reached 6 thousand, and according to more conservative estimates - 2-3 thousand. Now there are 200-400 whales in the Sea of Okhotsk, which is 10-13% of the original population. Apparently, individuals from this population made separate trips to the south.
The main reason for the decline in the number of bowhead whales is overfishing in the 18th-19th centuries. Low fertility - the birth of a single calf every 4-7 years, a disturbance factor due to increased shipping, ocean pollution, which negatively affects the food supply, also to some extent limit the rate of restoration of the numbers of these whales.
Minor damage is caused by enemies - killer whales and sharks, as well as rare cases of whales freezing into the ice. The growth of the bowhead whale population, despite the existing long-term fishing ban (since 1935), is very slow. They tried to explain this by saying that the species had already stabilized its numbers, but at a very low level. However, the fact that the population is growing extremely unevenly (the Bering-Chukchi herd is growing relatively faster) rather indicates that limiting factors have been poorly studied, especially for the Svalbard herd.
Security: Listed on the IUCN-96 Red List, Appendix 1 of CITES. In 1935, hunting the bowhead whale was prohibited by the International Whaling Convention; in 1946, the ban was again reinforced by a decision of the International Whaling Commission
