The Humpback Whale

The Humpback Whale - 2

Origin

The humpback whale is a marine mammal of the Balaenopteridae family (brazed whale), being the only representative of the Megaptera genus (humpback whales). The name of this species comes either from a dorsal swing that reminds of a hawthorn, or from an animal’s habit of bouncing strongly back during swimming.

The name of the megapetra genus comes from the “huge” Greek words and “the wing” referring to the extraordinary dimensions of the side swings.

It is a cosmopolitan species found throughout the planetary ocean and partly in the large semi-enclosed tropical to the large latitudes except the Arctic and Antarctic. Despite the wide spreading area, the population of whales is rarely rare.

He prefers seashore and seawater, going out into the ocean only during migrations. The northern hemisphere humpback whales are closer to shore.

Humpback Whale Groups migrate both locally, looking for food, and seasonally, with the change of seasons. They spend the warm season in cold and temperate areas, and the cold in subtropical and tropical waters for reproduction.

According to research, the humpback whales hunt in waters with a temperature of 21-28 degrees.

Every year, migrations take place in a pre-established order. At the end of the autumn, the first to go to the south are the mothers with breastfed whale babies that are moving the most slowly. After them go young whales, adult males, unmarried females, and finally pregnant females. At the end of winter, migration takes place in the same order, but in the opposite direction.

Humpback Whale’s Food

Humpback whales feed on sandy areas, and during migrations they are hungry to survive thanks to fat reserves under the skin. In winter we lose 25-30% of the weight.

The whales feed on pelagic crustaceans, fishponds and, more rarely, with cephalopod molluscs. This is because of this food ration that the whales prefer the small seas near the seaside.

The diet of the North Atlantic populations is made up of fish. Preferred species are herring (Clupea), squirrel (Scomber scombrus), sardines (Sardinops, Sardinella), capelin (Mallotus villosus), [2] Eglefin (Melanogrammus aeglefinus), Cod (Gadus morhua), Eleginus gracilis, Theragra chalcogramma, Boreogadus saida , fish of the genera Ammodytes, Pollachius and Engraulis.

The species Pleurogrammus monopterygius and the genus Scomberesocidae are the preferred whales of the northern Pacific.

In the whales’ stomach 500-600 kg of food, equivalent to 600 herring or 800 Alaska pollack fish, can fit. in the belly of some individuals were discovered and the digested remains of some marine birds.

Hump ​​pack is a very large animal with the gauge of a bus. The average body length of an adult varies between 13.5 m in males and 14.5 m in females.

Humpback Whale’s Features

The most imposing humpback whales reach the length of 17-18 m but are rarely encountered. The average weight is 30 t, and the maximum weight is 48 t. Of all the whipped whales, the humpback have the thickest fat layer in relation to the body size, which is still thinner than the blue whale.

Apart from the size, the only difference between males and females is the genitourinary shape of the uro-genital area: the females have a hemispherical prominence with a diameter of approx. 15 cm at the end of the genito-urinary tract.

The hump is different from the other whales bracing the shape and color of the body, the shape of the dorsal fin, the size of the pectoral, the “warts” on both lips and the pectoral fins and the irregular edge of the tail.

The corpse of the whale is short and “crowded,” licking in the front and slancing towards the tail. The head is wide, with the lips rounded in front; in some individuals it is only 3.2-3.5 times shorter than the whole body. The lower, massive front lip comes out 10-30 cm in front. The abdomen is lowered.

The pectoral (or lateral) swimmers are very long (28.3-34.1% of the body length), peculiarity reflected in the genus name – Megaptera. The exaggerated dimensions of the pectoral swings are explained by their participation in locomotion and thermoregulation. the dorsal swing is quite short, reaching 30-35 cm in height, instead it is thick and muscular; is located in the posterior half of the body.

The codend (or, more simply, the tail) is very large, with the underside and rectangular posterior edge positioned horizontally, as with all whales.

The color of the whales varies from one individual to another, which makes it easier to identify them. The back and sides are black or dark-gray, sometimes dark brown, always darker in color than other brazen whales.

The color of the throat and abdomen varies from black or pale (with white spots) to white. The pectoral swimmers are black, padded or white overhead and white underneath, but meet whimsically wholly or totally black swimmers.

The color of the upper part of the tail coincides with that of the back and the lower part with that of the abdomen. Albinos of this species are rarely encountered. Since each individual has their own color, they can be identified by the color of the lower part of the codend, which becomes visible during the dive after a jump over the water.

The vertebral column of the whales has 7 cervical vertebrae, 14 pectorals, 10-11 lumbar and 21 codels (total 52-53).

The humpback whales are grayish-black with brown, harsh fringes, sometimes the earlier frowns may be lighter or even whitish. Each half of the upper jaw has between 270 and 400 pans with a maximum length of 1 m (usually no more than 80 cm). Annually, they extend 8-11 cm. There are two longitudinal furrows on the neck of the neck and the abdomen.

Humpback whales are coastal animals and go ashore only in search of food and during migrations. Sometimes they get into the bays. during winter, mothers with chicks stay longer in shallow waters than other individuals.

Humpback whales do not have a well-defined living area, but some individuals and groups are returning to the same waters every year. Whales can change their summer and winter habits The humpback whale moves slower than other whipped whales, with their swim speed varying between 8 and 15 km / h. At the same time, the whale is one of the most energetic and “acrobatic” whales, its jumps above the water attracting the attention of tourists.

Hermann Melville describes it in the Moby Dick novel as follows: “It is the most playful and whiter the whale, scarps more foam than the others.”

Often, the humpback whale strikes the pectoral and codal fins on the surface of the sea, causing the foam, rolls on the back, pulls its head out of the water. Sometimes, they jump completely over the water in a vertical position for it to fall down with deafening. Such behavior is demonstrated in all seasons and by all individuals, including those who live in loneliness, but its purpose is not determined.

The duration of the dive depends on the season. Summer whales do not stay under water for more than 5-10 minutes, but the winter lasts 10-15 minutes (at most 30). Probably in the cold season it sinks to rest, and in the warm one rest on the surface.

Exiting above water, humpback whale emit water jets of 2-5 m in height over a range of 4-15 s. Due to the habit of raising their codecs during diving, they can be easily identified, as the color of the lower tail portion differs from one individual to another.

Humpback whales do not form long-term groups. Apart from the mother’s affection for babies, relationships between individuals are usually unstable and groups are spreading quickly.

During migrations and breeding regions, humpback whales are in groups of 2-15 individuals (most often 3-5), but they travel without a companion. Females with babies are often escorted by an adult male.

These “escorts” are also short-lived, since at any time another male may appear to chase the previous one. To show their superiority, males sometimes struggle with sea-going vessels on the surface. It has been found that lonely individuals are less aggressive than group members.

Humpback Whale’s Reproduction

Humpback whales are known for their unusual vocal repertoire, which probably plays a prime role during reproduction. Although females can make different sounds, only males can “play” long-lasting songs.

Each song is composed of some sounds dropped in a lower register, varying in amplitude and frequency, and lasting about. 10-20 minutes.

Songs can be repeated for several hours or even days. Males that escort females with chick sing more often than the rest. The songs differ from one population to another and can change during reproduction. The ballets sing both “solo” and group.

Like most whales, reproduction takes place in a particular season of the year. Reproduction, gestation and birth are usually concentrated in the winter-spring season when in subtropical or tropical waters. in this period, females enter the estrus, and spermatogenesis is increased in males. Ovulation of females in southern hemisphere populations ranges between June and November, culminating in late July.

Few females ovulate twice a year (16-28%) and those ovulating 3 times a year make up only 8% of the total female population. 2-20 males fight to conquer a single female. Sexual activity takes place in a very romantic atmosphere: the male and female swim one next to each other, touching the pectoral fins, hitting the water with the tail, then slowly rising to the surface, swimming vertically in the spiral, with the abdomen glued.

Gestation lasts about 11 months. The embryo develops very fast, increasing by 17-35 cm per month. Newborns have an average body length of 4.5 m and a weight of between 700 kg and 2 t. Mothers breastfeed the little ones up to 10-11 months, however, the baby can feed on its own already at the age of six months.

When the baby is “weaned”, it already measures 8-9 m and weighs 9 tons. The little whale consumes 40-45 kg of milk a day, with a fat percentage of 45-49%.

Mothers take care of their offspring until they reach the age of one year, less than two years old. The injured ones are removed to the adult surface to force them to breathe. Males do not take part in caring for them.

The exact longevity of humpback whales is not known, and this is possible because of the excessive whaling of the past, in which a lot of old individuals have been captured. Ipotetically, whales live around 40-50 years.

The oldest male ever captured, judging by the wax layers in the auditory channel, was 48 years old. The oldest woman was only 38.

They have few natural predators. during migration, young individuals can be attacked by orcs and sharks, which leave scarring on the tail and pectoral swellings. Diseases that are virtually untreated have not been studied.

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