Pink or Amazon river dolphin. Pink dolphins

The Amazon dolphin is largest species of river dolphin, they usually grow up to two and a half to three meters in length and reach a weight of more than two hundred kilograms. Everyone who has ever met a bouto and seen them in person noted that they were plump, and their muzzle and tail were rather narrow. Which is strange with such a body volume. Buto have a steep rounded forehead, a long beak curved upward, covered with stiff bristles on top and bottom.

Nature knows how to surprise, despite the fact that we have already seen a lot in our lives, are familiar in person or from photos with various wonderful and unusual creatures of flora and fauna, there are still animals that can surprise even experienced zoologists with their existence. One of the brightest representatives of such wonderful animals is the river Amazonian dolphin. This species also goes by the following names:

Amazonian inia.
Bouto.
White river dolphin.
Pink dolphin.

Yes, Amazonian hoarfrosts have many names, but they all boil down to the fact that their owner is a river mammal, a dolphin with an unusual color.

It is almost impossible to see such an animal live. In an aquarium or zoo, pink dolphins are not able to live longer three years. Thus, it turns out that they die before they even reach sexual maturity. This suggests that they do not reproduce in captivity.

And keeping such dolphins is not very profitable: they will not be able to participate in various shows for the audience. After all, despite the fact that botos easily get along with people and are tamed, they are absolutely not amenable to training and refuse to perform even the simplest tasks or tricks. In addition, the character of these wonderful creatures deteriorates greatly in captivity and they become terribly aggressive towards people and fellow creatures.

Externally, Amazonian river dolphins are very different from other species of these mammals. Main feature bouto is a color change skin depending on age. The color of such an animal is very diverse in its variations. You can find river dolphins from bright red tones to very dark shades.

Typically, the body of Amazonian hoarfruits is bluish on top and reddish or pink underneath. With age, the color becomes lighter and lighter.

Nature has awarded the pink dolphin with a large number of teeth, usually more than a hundred. The bulk of a bowto's diet consists of solid food, so their teeth wear down quickly and are not very sharp.

One more distinctive feature This type of dolphin is their eyes. They are very small in size and consist of a cornea and lens, colored yellow. Thus, nature protected the buto's eyes from bright sunlight Amazonia.

Well developed and quite long neck allows the inia to turn its head, and the hump on the back replaces the upper fin. These dolphins have very thick cheeks, which is why they have to scan the bottom for food by swimming belly up. This gives them the opportunity to see what is happening underwater.

Lifestyle

These wonderful creatures live on the mainland of South America, in the Amazon River basin and throughout its entire river system of sources and tributaries.

You can meet the Amazonian dolphin in bodies of water:

Bolivia.
In the north of Peru.
Brazil.
Venezuela.

Some tributaries of the Amazon originate in the Orinoco River, so boutos are often spotted there too. In Latin America, the population of these animals is also widespread; the size of rivers or lakes does not matter much to them.

It is worth noting that the habitats of pink dolphins are as fabulously beautiful as the animals themselves. The waters of the Amazon are not clear, but white as milk. The huge amount of silt at the bottom gives this color to the river. This river is also home to the largest water lily in the world, named Victoria Regia or Victoria Amazonian. Along the banks of the Amazon grow a variety of unusual tropical plants and trees, as well as many palm trees.

IN natural environment Amazonian dolphins tend to spend their entire lives in only one place; they can only be forced to move to another part of the river or to another body of water by seasonal drops in water levels. In such cases, they go in search of a place where the riverbed is deeper. When river system returns to normal, the buto return home.

After heavy rainfall rivers often overflow their banks and overflow coastal zones. In such cases, local residents can often observe bootos frolicking in flooded areas. During the rainy seasons, some individuals may move to another river.

Unlike sea dolphins, which live in schools, Amazonian dolphins are solitary. They gather only during the mating season.

Sometimes you can see two such dolphins together - this is a mother and her calf.

The reproductive biology of this species is still little studied. There are suggestions that the buto are polygamous creatures. This conclusion was made on the basis of sexual dimorphism. Also, one of the signs of polygamy is aggressive fights between males for possession of a female. Fights are repeated every mating season and leave battle marks on the skin of males: bites and abrasions.

After the end of the breeding season, the males return to where they came from to mate, while the females remain in the channels or in flooded areas and wait for the cub to appear. The pink dolphin's pregnancy lasts about eleven months, and birth takes place within four to five hours. After the baby dolphin is born, the female herself pushes it to the surface so that it can take its first breath. Immediately after birth, the cub has a body seventy to eighty centimeters long and weighs six to eight kilograms.

Females with dolphins prefer to stay in shallow water as long as possible. Choosing such a place habitat is explained by a number of advantages.

Calm water, no strong current that the baby may not be able to handle.
There are no aggressive males nearby.
Large quantity varied food and lack of competition from other animals.
Lack of natural enemies.
The shallow depth allows the cub to independently and without problems float to the surface to take in air.

Females feed their young throughout the year from the moment of their birth, but they remain next to their mother for about three years. Typically, pink dolphins take fifteen to thirty-six months between births. It is not uncommon for a lactating female to be pregnant again.

Sexual maturity in Amazonian dolphins occurs in the fifth year after birth. At this moment, the body length of females is one and a half to two meters, in males from two or more meters.

The lifespan of a booto in the natural environment is at the moment is not yet known, but when kept in captivity they rarely live beyond thirty-three months.

Because Amazonian dolphins are solitary, they have no hierarchical division among their brothers. But this does not in the least prevent them from communicating with each other from time to time. For this, dolphins use about ten to twelve different sounds, reminiscent of high-pitched screams, barking, clicking, squealing and echolocation.

Buto are very active creatures; regardless of the time of day, they are always alert and busy swimming, communicating or searching for food. Representatives of this species swim rather slowly, the maximum speed they can reach is three kilometers per hour. But any modern boat cannot compare with them in maneuverability.

When diving, ini can survive under water for up to two minutes. In this way, they tear through the mud at the bottom to find hiding fish or crabs. Pink dolphins prefer to forage for food off the coast, at river mouths or near waterfalls. Of course, the water in these places cannot boast of cleanliness and transparency, so both to a greater extent rely on echolocation and hearing rather than vision.

Amazonian dolphins eat about twelve kilograms of food per day. Usually these are small fish, but turtles and crabs are also in demand among these creatures, and they will not refuse to feast on them, even if they are full. Such a “brutal” appetite explains the excessive fatness of the buto.

Sometimes inias team up with tukashi dolphins or large otters to drive a large school of fish, and then divide the prey among the participants in the hunt.

Role in the ecosystem

Pink dolphins play a big role in maintaining river ecosystems South America. Eating various types fish and even piranhas, they restrain the uncontrolled reproduction of these creatures. Buto never abandons their relatives in trouble and help them recover from their wounds.

The Amazon dolphin is the largest of the river dolphins. These dolphins are also known as bouto or inia.

The body length of these dolphins reaches 2.5 meters. Juveniles are light gray in color, which becomes lighter with age.

They have a full body, while the tail and muzzle are narrow. The eyes are small, the forehead is round, the beak is slightly curved - this is characteristic features Amazonian dolphins.

Representatives of the species live in water bodies Latin America. Depending on their habitat, 3 subspecies are distinguished: Inia geoffrensis boliviensis, Inia geoffrensis geoffrensis and Inia geoffrensis humboldtiana.

The habitat extends to the entire Amazon River basin, these live even in small lakes and rivers. Most often, they live in one place all their lives, only moving during seasonal migration. But if the water level in the river drops, dolphins have to find new channels. When the river floods, they can settle in flooded flat areas. During the rainy season, dolphins often move from one river bed to another.

Amazonian dolphins do not live in groups; only during the breeding season do they occasionally unite in small groups. Because they don't have social life, then there is no hierarchy. These dolphins are active both day and night.

Compared to other dolphins, ini have a different high speed- approximately 3 kilometers per hour. But if necessary they can swim with maximum speed 22 kilometers per hour. They can stay under water for up to 2 minutes. Amazonian dolphins can maneuver perfectly while swimming.

The diet of Amazonian dolphins consists of small fish. A dolphin consumes about 12 kilograms of food per day. They feed not only on fish, but also on crabs and turtles.

Dolphins get food from the banks of rivers or near waterfalls, since in these places the water is not clear and the fish do not have time to hide from the predator. In addition, Amazonian dolphins look for food in the mud. They also steal fishing nets. They sometimes hunt alongside dolphins and giant otters. Although Amazonian dolphins have good eyesight, during hunting they use touch, hearing and echolocation.

Amazonian dolphins living in nature are very curious and playful, they show interest in everything around them. They never leave their loved ones who are in trouble. Amazonian dolphins do not shy away from people and approach boats without fear. They can get used to humans, but they cannot be trained. In captivity they begin to show aggression, which is why they do not live in oceanariums.

Scientists probably do not know how reproduction occurs in Amazonian dolphins. There is an opinion that males fight for females. After the female gives birth to a baby, she lives with him for a long time in shallow water, because there it is easier for him to emerge to breathe. In addition, they do not live in shallow water large predators, and it’s easier to find food here.

The mother feeds the baby with milk for a year, but he does not leave her longer, remaining with her until he is 3 years old. Representatives of the species begin puberty at the age of 5 years. It is unknown how long Amazonian dolphins live in the wild, but they do not survive in aquariums for more than 33 months.

Inia geoffrensis (Boto)
Order Cetaceans - Cetacea
Suborder Toothed whales (Odontoceti)
Family River dolphins (Platanistidae)

This is the largest of river dolphins and relatively easy to observe. Other names - Amazonian river dolphin, pink stormy dolphin, pink dolphin., is considered by most of the scientific community to be a subspecies of the Amazon River dolphin.

General information

Status- vulnerable type (vulnerable)
Habitat- in rivers.
Number of groups- 1-2 (up to 15 during the dry season or in places rich in food).
Dorsal fin location- slightly behind the center.
Newborn weight- 7 kg.
Adult weight- 85-160 kg.
Newborn length- 75-80 cm.
Adult Length- males reach a length of 2.5 m, females are much smaller.
Lifespan unknown in nature.
Eating fish and crabs.

Area

The range covers the Amazon River system with its tributaries in Brazil, Bolivia, Northern Peru, Ecuador, Colombia, Venezuela (upper reaches of the Rio Negro), as well as the Orinoco River system, covering about 7 million km².

Highlight 3 (1998):

Inia geoffrensis geoffrensis- found in the Amazon basin;
Inia geoffrensis boliviensis- in the upper reaches of the Madeira River, separated from the rest of the Amazon by impassable rapids (Bolivia); in some classifications it is considered as a separate species;
Inia geoffrensis humboldtiana- Orinoco basin.

Population size and status

Amazonian inia is the most prosperous species among river dolphins. However, in the lists of the International Red Book it has the status "vulnerable species"(vulnerable).

Compared to the rapidly declining ranges of the lake and Gangetic dolphins, the range of the inia remains stable, and determination of the number is difficult due to the inaccessibility of its habitats. Presumably it is calculated tens of thousands.

Population increase and anthropogenic pressure have an impact on the environment negative influence on the ini population. Reducing the number of fish as a result of fishing is one of the problems. Hydroelectric dams both impede fish migration and separate ini populations, potentially reducing genetic diversity within subpopulations.

Deforestation in flooded areas leads to a decrease in the food supply for fish that serve as food for frost. Finally, water pollution agricultural pesticides and heavy metals (including mercury) from gold mines have a particularly negative impact on dolphins and their food supply.

Appearance

Steep forehead; a thin, slightly downward-curved beak with short bristles on the upper and lower jaws. They are located randomly and their ends are always directed backwards. The crescent-shaped blowhole is slightly shifted to the left. The neck crease may be noticeable. The neck is quite well defined, and the head can turn right and left up to 900. A hump replaces the dorsal fin. The dorsal spine extends in front of and behind the hump. The full body becomes thinner towards the tail.

The ini's eye is different from other cetaceans. If in Cetacea all adaptations are aimed at catching weak light, iniia have, as it were, “sunglasses”: the cornea and lens are yellow in color, protecting the eyes from sunlight.

This, as well as the large and protruding retina, the relatively large and retracted lens, indicates the adaptation of the eye to aerial rather than underwater vision. However, the behavior of the inias does not confirm this.

Young inii are pale-gray, adults are pale blue above, white below, sometimes pinkish; In lakes, individuals are darker than in rivers. The eyes are very small (the horizontal diameter of the eyeball is 13 mm, and the vertical diameter is 12 mm), but they function well.

The edges of the fins are often frayed. Teeth marks on the fins are left by relatives during fights or when pushing individuals out while helping them.

bright pink, bluish-gray or not quite white body
hump and ridge are replaced dorsal
large, paddle-shaped fins
long beak
plump body
slow swimmer
can make small jumps

Lifestyle and nutrition

Mostly saddles However, they perform seasonal migrations depending on fluctuations in water levels.

During the dry season, when the rivers become shallow, the ini stay in the riverbeds large rivers. During the rainy season, they move into small channels, as well as into flooded plains and forests. During river floods, Indians can swim across flooded land from one river basin to another.

Inias, as a rule, live alone or in pairs (usually a female with a baby), rarely in groups of 3-6 individuals. Large flocks are observed in areas rich in food or during the breeding season.

Not territorial. They do not establish a social hierarchy (in captivity), but they often show aggression towards each other, sometimes leading to death. Active both during the day and at night.

They swim slower than most dolphins: their usual speed is 1.5-3.2 km/h, maximum speed is 14-22 km/h. Very maneuverable. They dive shallowly; remain under water for 0.5-2 minutes. When exhaling, small fountains are released. They can jump more than 1 m out of the water.

Feeds food mainly small fish, eating 9-12 kg per day (about 2.5% own weight). Their diet is very diverse, including at least 43 species of fish from 19 families; prey sizes vary from 5 to 80 cm.

They prefer fish families Gorbylevs(Sciaenidae), cyclide(Cichlidae), characins(Characidae) and piranhas(Serrasalmidae); the structure of their teeth allows them to also eat Amazon river turtles(Podocnemis sextuberculata) and crabs(Poppiana argentiniana).

Their diet is most varied during the wet season, when the fish move to flooded lands and become more difficult to catch, and is more selective during the dry season. Ini feed most actively between 6-9 a.m. and 3-4 p.m.

They often hunt near the shore, in river mouths and under waterfalls, as well as where two rivers merge and the turbidity of the water disorients the fish, making it easier to catch. They dig through mud with their beak, taking food from the bottom. They can enter nets and steal fish from there.

In nature, inies are playful and quite curious. They take care of wounded and stranded relatives. They can swim up to boats and rub against them.

Lifespan in nature unknown. In captivity, Indians usually live no more than 33 months, although individuals have been known to live up to 10-26 years.

Cubs

The biology of reproduction is poorly understood. Presumably polygamous(signs of this are sexual dimorphism and aggressive behavior males). Males are often covered in bite marks and abrasions received during competition for a female.

Pregnancy lasts 11 months; labor lasts 4-5 hours. Birth the only one hatching occurs in May - July, i.e., during the period when the water is at its highest. The length of a newborn dolphin is 75-80 cm, weight is 7 kg; the female pushes it to the surface for the first breath.

Females with cubs remain in channels and on flooded plains when the water begins to subside (males return to the rivers earlier). This habitat has a number of benefits, including more food, the absence of strong currents and predators, and a reduced risk of aggression from adult males.

Lactation lasts up to 1 year, although the cub can stay close to its mother for up to 3 years. The interval between births is 15-36 months; frequently lactating females pregnant at the same time. Males and females reach sexual maturity by 5 years, with a body length of 2 m (males) and 1.6-1.7 m (females).

Amazonian inia and man

Commercial significance doesn't have. Portuguese colonists previously hunted river dolphins for lamp oil, but locals traditionally did not use their meat or skin. Body parts of dead frosts are used for amulets; fat in traditional medicine used as a remedy against asthma and rheumatism.

In the folklore of the Amazon peoples, boutos appear as the reborn souls of drowned people, or as werewolves (encantado), taking the form of beautiful young men and women. In addition to dispersing piranhas, anglers use their presence to detect schools of fish.

They catch frost, as a rule, by accident, when they inadvertently fall into fishing nets. They are also caught and destroyed by fishermen for damaging their nets and reducing their catch. Since 1988 this practice has been prohibited in Brazil and Bolivia and limited in Peru, Venezuela and Colombia.

They are well tamed, but they are aggressive and difficult to train, so they are quite rare in aquariums and oceanariums.

In aquariums, ini have 8-12 different types sounds: echolocation clicks, screams, high-pitched squeals, threat signals, barks, whimpers and others, but there were no whistles.

There are only four species of dolphins on the planet that are capable of living in fresh water and the Amazonian dolphin is one of them. It is known by many names - Amazonian dolphin, white river dolphin, inia, bouto and Amazonian river dolphin.

photo: Joachim S. Müller

The Amazon dolphin (Inia geoffrensis) is an aquatic mammal of the suborder of toothed whales. This is a medium-sized dolphin, with males larger than females. They can weigh about 160 kg and up to 2.5 meters in length. Their feature is the absence of a dorsal fin and more long nose than most other dolphin species.

They are very intelligent animals, just like all species of dolphins. When looking at their anatomy, it was found that their brains were 40% larger than the average human. Many people find it fascinating that the Amazon dolphin can move its head 180˚. This is possible because his vertebrae are not fused.

photo: Joachim S. Müller

There is a common misconception that the Amazon dolphin is a slow swimmer due to its body shape. In fact, it is capable of swimming faster than most other dolphin species. However, as a rule, he simply does not have such a need. These dolphins swim at a slower pace to conserve energy.

Everyone knows that dolphins are very social animals and the Amazon dolphin is no exception. They usually do not gather in groups of more than four individuals. However, this does not mean that they do not communicate with each other. Very in important ways communication counts include chirps, clicks and whistles, as well as many non-verbal signals.

photo: Paulo Neves

They are very tolerant of each other as they are not territorial. The range they use to search for food often brings them into contact with each other. Many experts as well as observers are fascinated by the antics of Amazonian dolphins. They often rise to the surface, where they perform many interesting and exciting tricks: moving on their sides, swimming on their backs, jumping and spinning.

As you may have guessed from their name, these dolphins are native to the Amazon River. They are also found in the Madeira and Orinoco rivers. Amazonian dolphins live only in fresh water with warm temperatures.

photo: Gabrielle Sim

They migrate to find more warm water in the cool season. This can also cause mating because it tends to be very popular during migration. Migration also helps to obtain enough food.

The Amazonian dolphin feeds mainly on small fish, eating 9-12 kg per day (about 2.5% of its own weight). Its diet is very diverse, including at least 43 species of fish from 19 families. All food is consumed whole, so it is easy for this dolphin to eat entire schools of fish.

photo:PRO Harold Moses

Females are ready to breed at the age of about 7 years, and males about 10. Partners search for each other using vibration and through the use of their voice messages. Before they begin mating, they will go through a courtship process. During this period, the couple will spend a lot of time communicating and playing.

The gestation period lasts 11 months. After which the female gives birth to one calf, which weighs about 7 kg and is 75-80 cm long. It can stay with its mother for up to three years. During this period, his mother prepares him for independent life.

Since these dolphins live primarily in the Amazon River, where there are no sharks or killer whales, they have no real problems with predators. However, they certainly have a few problems with people.

The Amazon dolphin is classified as a vulnerable species on the IUCN Red List.

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The Amazon dolphin (lat. Inia geoffrensis) belongs to the family Iniidae from the suborder of Toothed whales (Odontoceti). It is also called inia. Among the Indians of the Amazon, there is a widespread belief that tipsy white tourists who decide to swim in local rivers in a drunken state regularly turn into it.

Having visited long time in the skin of an animal, they sometimes take on human form again and then behave more civilized.

In the vicinity of the Rio Negro River, old-timers claim that they have witnessed how cunning dolphins sneak into Indian settlements on full moon nights in the guise of representative lords in white suits and hats, and return back to the river in the morning. Because of such nightly promenades, young dark-skinned women are increasingly giving birth to light-skinned babies.

This was even filmed in Brazil in 1987 feature film Ele, o boto (He, the Amazonian dolphin), which aroused great interest among sentimental Brazilians. In it main character he flatly refused to recognize the aquatic mammal as his son and even tried to kill him. The burning brunettes were indignant at his unworthy behavior for a long time.

Spreading

There are 2 known subspecies that live in the northern part of South America. Subspecies I.g. geofrensis is found in the Amazon and its tributaries, and I.g. humboldtiana is distributed in the Orinoco and its basin. Since 1994, previously considered as subspecies I.g. boliviensis is considered a separate species, diverging from its fellows about 2.8 million years ago.

The Amazon dolphin is observed in Bolivia, Brazil, Colombia, Ecuador, Peru and Venezuela. Total area The area it occupies is approximately 7 million square kilometers.

During periods of heavy rainfall and subsequent floods, mammals are able to change their place of residence and migrate to areas richer in food, including flooded plains. Seasonal migrations depend on the water level in reservoirs. During drought, animals gather in the beds of deep rivers.

Behavior

Representatives of this species usually live in pairs or alone, sometimes in groups of up to 4 individuals. Most often you can observe a female with her cub in natural conditions. During high-water floods, they prefer to hunt individually, and during periods of drought they are able to unite for joint hunting.

Unlike Amazonian dolphins, with less socialization, they have a calmer and more balanced character. As a rule, they do not show aggression towards their fellow tribesmen.

These animals are not very playful and do not like jumping into the air, but they are very curious and study with interest any objects that are unusual for them. They willingly grab fishermen's oars and rub their bodies against fishing boats, they can catch thrown sticks, and sometimes they entertain themselves with turtles like balls. They are amenable to training much worse than other related species.

Inia is a relatively slow swimmer. Its normal speed is 1.5-3 km/h, but if necessary it can swim at a speed of 14-22 km/h.

Then the tip of its snout, part of the head and the dorsal fin appear above the surface. To monitor environment dolphins put their heads above the water; young animals, unlike adults, often jump up to 1 m above the water surface. They breathe every 30-110 seconds.

Nutrition

The Indian's daily diet is very varied. It includes about 43 different fish from 19 families. The length of prey ranges from 5 to 80 cm, but the predominant prey is about 20 cm. The most common prey are cichlids, tetras and. The structure of the teeth allows them to bite through the shells of crustaceans and turtles.

Animals feed around the clock, but their peak activity is observed in the early morning and afternoon.

For more effective hunting, they are often located near waterfalls and river mouths, where it is much easier to catch fish. When the opportunity arises, small fish (Sotalia fluvialis) and (Pteronura brasiliensis) become their prey.

In captivity, Inia geoffrensis have been repeatedly observed sharing food among themselves. Whether they do this in natural habitats is unknown. Their natural enemies are black caimans (Melanosuchus niger), bluntnose sharks (Carcharhinus leucas), jaguars (Panthera onca) and (Eunectes murinus).

Reproduction

Sexual maturity in females occurs at the age of 6-7 years, when they grow to 175-180 cm. Males become sexually mature 2-3 years later, reaching a body length of more than 2 m. Mating season takes place during the dry season, when rivers become shallow, and lasts about a month. Duration of mating is 3-4 hours.

Pregnancy lasts approximately 315 days, and childbirth lasts 4-5 hours. Cubs are born during floods in May or June. Newborns weigh about 8 kg and feed on mother's milk for a year. Their body length is about 80 cm. The interval between pregnancies is 2-3 years.

The bond between a mother and her child is very strong. Usually he leaves her and moves on to independent existence only after the appearance of the next offspring.

Description

The length of adult individuals is 2-2.5 m, weight 100-150 kg. Males are larger than females and some can weigh up to 207 kg. The weight of females does not exceed 154 kg.

Skin color changes with age. In young animals it is dark gray, but gradually changes to silver and pinkish. Males are painted in brighter colors. In adults, the back is dark, dark pink or even brown. Color is also affected by water temperature and geographic location.

The structure of the cervical vertebrae allows you to turn your head in different sides at 90°. Large pectoral fins remind isosceles triangles. Thanks to the long humerus bones, they have a high degree of mobility and allow the animal to easily maneuver in the thick of aquatic vegetation. The dorsal fin is relatively poorly developed, and the caudal fin is wide and triangular in shape.

The eyes are small, but provide good vision in water and air environment. There is a characteristic thickening on the head used for echolocation. The narrow, elongated muzzle ends with a beak slightly curved downwards. The front teeth are sharp and conical, while the back teeth are flat and blunt. The mouth can have from 88 to 144 teeth.

Lifespan of an Amazonian dolphin wildlife not reliably known, presumably 20-30 years. In captivity they usually do not live longer than 3 years. The exception was the male Apure, who was caught in 1975 in the waters of the Orinoco River and then lived in the Duisburg Zoo in Germany. He died of old age on October 9, 2006, at the age of almost 50, according to zoologists.