A dolphin is a representative of the suborder of toothed whales, the order of cetaceans, and the dolphin family (Delphinidae). The graceful body of the dolphin has a spindle-shaped, streamlined shape, which allows these mammals to quickly cut through the surface of the water. The dolphin's speed reaches 50 km/h.
People and dolphins
People have known about the extraordinary intelligence and intelligence of dolphins for a long time. These adorable animals rescue people from ships in distress, preventing them from drowning. You could even say that dolphins are the smartest animals on the planet. Many trainers believe that the intelligence of dolphins can be equated to that of humans, these animals behave so intelligently and unusually.
There is a joke about dolphins that says that if a person had not overtaken the dolphins and had not climbed down from the tree earlier, they would have come out of the water and now would have been the kings of nature, replacing us.
The dolphin is smart, kind, beautiful, he is an excellent learner, analyzes and remembers.
Dolphins are directly related to the formidable inhabitants of the oceans, killer whales and whales. There are about 50 species of dolphins. These include the harbor porpoise, black dolphin, gray dolphin, white-faced dolphin, and Atlantic white-sided dolphin.
The most popular is the bottlenose dolphin (large dolphin), which is what people mainly mean when talking about encounters with representatives of this species. They are well studied and tamed. Bottlenose dolphins are featured in films and participate in programs for the rehabilitation of children suffering from various neurological ailments.
Dolphin - description and photographs. What does a dolphin look like?
A dolphin is not a fish, but a mammal. Common to all species is an elongated, streamlined body, which is crowned by a small dolphin’s head with a beak-like mouth. Each jaw has 80-100 small conical teeth. The dolphin's teeth are slightly inclined inward. The transition between the muzzle and the frontal part is well defined. Almost all members of the dolphin class have a prominent dorsal fin. The skin is elastic and smooth to the touch. The length of a dolphin can reach 4.5 meters depending on the species.
Dolphins move very easily in the water; they practically do not feel its resistance thanks to special fatty secretions on the skin that facilitate gliding. Interestingly, the friction of water quickly wears off a dolphin’s skin. Therefore, in the deep layers of the skin they have a significant supply of regenerating cells. The dolphin constantly sheds, changing up to 25 layers of skin per day!
Dolphins have small eyes and poor vision. This is due to the fact that animals practically do not use them for hunting. The nostrils are transformed into a blowhole located on the crown.
How do dolphins breathe?
Whales and dolphins are related and can stay underwater for long periods of time without surfacing. The blowhole is closed during such periods. But, like other cetaceans, dolphins still need air underwater and periodically float to the surface to breathe.
Do dolphins have ears?
Dolphins do not have ears. But this does not mean that they have no hearing. Eat! True, it functions differently from other mammals. Sounds are perceived by the inner ear, and air cushions located in the frontal part serve as resonators. But these animals are fluent in echolocation. They accurately determine the location and dimensions of an object by the reflected sound, and the distance to it by the wavelength.
How do dolphins sleep?
Dolphins also have another interesting physiological feature: They never sleep. Animals hang in the water column, periodically rising to the surface to breathe. During rest, they are able to turn off alternately the left and right hemispheres of the brain, that is, only one half of the dolphin’s brain sleeps, and the other half is awake.
Where do dolphins live?
The dolphin's habitat is exclusively water bodies. The dolphin lives in almost all places on our planet, with the exception of the Arctic and Antarctic regions. Dolphins live in the sea, in the ocean, and also in large freshwater rivers (Amazonian river dolphin). These mammals love space and move freely over long distances.
Dolphin language
Dolphins are animals social, they live in packs, which can number from 10 to 100 (sometimes more) individuals, fighting off enemies with common efforts. Within the pack there is practically no competition or fights between them; fellow tribesmen coexist peacefully with each other. Dolphins communicate using sounds and signals. Dolphin language extraordinarily varied. The “conversation” of these mammals includes clicking, whistling, barking, and chirping. The spectrum of dolphin voices extends from the lowest frequencies to ultrasound. Moreover, they can put simple sounds into words and sentences, passing information to each other.
What do dolphins eat?
The diet of dolphins includes exclusively fish, with preference given to sardines and anchovies. The hunting method used by the animals is also interesting. A school of dolphins finds a school of fish and uses special sounds to force it into a tight group. As a result of such hunting, most of the school becomes prey for dolphins. This feature is often used by seagulls, attacking frightened fish from the air. There are known facts when dolphins helped fishermen by driving a school of fish into their nets.
Sharks and dolphins
Interesting fact: sharks and dolphins live in symbiosis. They often hunt together without showing any aggression towards each other.
Dolphin species
There are 17 genera in the dolphin family. The most interesting species of dolphins:
- White-bellied dolphin (black dolphin, Chilean dolphin) ( Cephalorhynchus eutropia)
lives exclusively on the coast of Chile. An animal with rather modest dimensions - the length of the stocky and rather thick body of this cetacean does not exceed 170 cm. The back and sides of the white-bellied dolphin are gray, while the throat, belly area and parts of the flippers adjacent to the body are completely white. The flippers and dorsal fin of the white-bellied dolphin are smaller than those of other dolphin species. This type close to extinction, protected by Chilean authorities.
- Common dolphin (common dolphin) ( Delphinus delphis)
The length of the sea animal often reaches 2.4 meters, the weight of the dolphin varies between 60-80 kilograms. In the area of the back, the common dolphin is colored dark blue or almost black, the belly is white, and along the light sides there is a spectacular stripe of a yellowish-gray hue. This species of dolphin lives in the Mediterranean and Black Seas, and feels at ease in the Atlantic and Pacific oceans. Common dolphin found on the east coast South America, along the coasts of New Zealand and South Africa, in the seas of Japan and Korea.
- White-faced dolphin ( Lagenorhynchus albirostris)
a large representative of cetaceans with a body length reaching 3 meters and weighing up to 275 kg. A distinctive feature of the white-faced dolphin is its very light, sometimes snow-white muzzle. The habitat of this mammal includes the waters of the North Atlantic, the coast of Portugal and Turkey. The dolphin feeds on fish such as capelin, navaga, flounder, herring, cod, whiting, as well as mollusks and crustaceans.
- Large-toothed dolphin ( Steno bredanensis)
The body length of this marine mammal is 2-2.6 meters, weight varies from 90 to 155 kg. The height of the dorsal fin is 18-28 cm. The color of the dolphin is dominated by gray, with whitish spots scattered throughout. This species of dolphin is common off the coast of Brazil, in the Gulf of Mexico and the Gulf of California, and lives in the warm waters of the Caribbean and Red Seas.
- Bottlenose dolphin (large dolphin or bottlenose dolphin) ( Tursiops truncatus)
The length of the animal can vary from 2.3 to 3.6 meters, and weight from 150 to 300 kg. The body color of the bottlenose dolphin depends on its habitat, but generally the species has a dark brown upper body and a grayish-white belly. Sometimes a faint pattern in the form of fuzzy stripes or spots is observed on the sides. The bottlenose dolphin lives in the Mediterranean, Red, Baltic and Black Seas, and is often found in the Pacific Ocean along the coasts of Japan, Argentina and New Zealand.
- Broad-snouted dolphin (beakless dolphin) ( Peponocephala electra)
distributed in the waters of countries with tropical climate, especially massive populations live along the coast of the Hawaiian Islands. The torpedo-shaped, light gray body of the animal is crowned with a cone-shaped head of dark gray color. The length of the mammal often reaches 3 meters, and an adult weighs more than 200 kg.
- Chinese dolphin ( Sousa chinensis)
This member of the genus of humpback dolphins lives in the waters along the coast of Southeast Asia, but migrates during the breeding season, so it is found in bays, quiet sea lagoons and even rivers washing Australia and the countries of South Africa. The length of the animal can be 2-3.5 meters with a weight of 150-230 kg. Surprisingly, although dolphin calves are born completely black, as they grow, the body color changes first to light gray, with slightly pinkish spots, and adults become almost white. The Chinese dolphin feeds on fish and shellfish.
- Irrawaddy dolphin ( Orcaella brevirostris)
A distinctive feature of this type of dolphin is the complete absence of a beak on the face and a flexible neck, which gained mobility due to several skin and muscle folds behind the head. The body color of the Irrawaddy dolphin can be either light gray with a blue tint or dark gray, while the belly of the animal is always a shade lighter. This aquatic mammal reaches 1.5-2.8 meters in length and weighs 115-145 kg. The dolphin's habitat covers the waters of the warm Indian Ocean, from the Bay of Bengal to the northern coast of Australia.
- Cruciform dolphin ( Lagenorhynchus cruciger)
lives exclusively in Antarctic and subantarctic waters. The color of the dolphin is black and white, less often – dark gray. The striking white marking covers the sides of the mammal and extends to its muzzle, framing the eye area. The second mark runs longitudinally along the back of the body, intersecting with the first and forming a pattern in the form hourglass. An adult cross-shaped dolphin has a body length of about 2 meters in length, the weight of the dolphin varies between 90-120 kilograms.
- Killer whale (killer whale) ( Orcinus orca)
a mammal that belongs to the dolphin family, the genus of killer whale. The male killer whale is about 10 meters long and weighs around 8 tons. Females are smaller: their length reaches 8.7 meters. The pectoral flippers of killer whales have a wide oval shape. The teeth of killer whales are quite long - up to 13 cm in length. The sides and back of the mammal are black, the throat is white, and there is a white stripe on the belly. There are white spots above the eyes. Sometimes completely black or white individuals are found in the waters Pacific Ocean. The killer whale lives in all waters of the world's oceans, except the Sea of Azov, the Black Sea, the Laptev Sea and the East Siberian Sea.
Dolphin breeding, baby dolphins
Dolphins do not have a distinct mating season. Reproduction occurs at any time of the year. As a rule, the leader of the pack mates with females. Pregnancy lasts approximately 18 weeks and is quite difficult. The female dolphin becomes clumsy, loses the ability to move quickly and often becomes the prey of enemies. A female dolphin gives birth to 1 calf approximately once every 2 years. Small dolphins, about 50-60 centimeters long, are born right afloat, fully capable and able to follow their mother from the first minutes.
Baby dolphins They feed on their mother's milk, eat often and grow quickly. Feeding stops by the age of one and a half years, when the baby dolphin begins to feed on fish on its own.
The upbringing and training of children is carried out exclusively by females. Male dolphins are not the kind of caring fathers.
- The level of development of dolphins is extremely high, so they devote a lot of time not only to obtaining food, but also to communication, games and even sex. These are perhaps the only animals (except humans, of course) sexual relations which go beyond procreation. These mammals play with great pleasure: dolphins jump out of the water several meters, simply hovering for a moment or making complex figures, pirouettes, and spins in the air. Playing dolphins often attract the attention of ship passengers.
- Unlike fish, a dolphin swings its tail in an up/down direction.
- In the mouth of a sexually mature dolphin there are 210 sharp teeth, and they play a role only in capturing food, but dolphins swallow their prey without chewing, since they do not have a chewing reflex.
- Dolphins don't sleep! More precisely, only one hemisphere of their brain sleeps, while the other is awake and intuitively pushes the dolphin to the surface of the water to take another breath.
- Currently, it is prohibited to hunt these interesting and charming animals. Despite all the protective measures, the number of dolphins is declining, and some of them are almost extinct. Nowadays, many water parks are working on breeding endangered species, as well as studying and training dolphins.
Dolphins have long been one of the most beloved waterfowl for humans. And this is not surprising! After all, dolphins are the most peaceful, intelligent and friendly creatures on the planet! When we talk about dolphins, we always imagine trained cetacean creatures performing acrobatic tricks. However, there are countries that are categorically against dolphinariums, believing that these smart creatures should not live outside the natural environment, because the number of dolphins is already significantly decreasing from year to year. And only the human factor is to blame for this.
A little history
It is assumed that the sperm whale, whale, dolphin, including the porpoise descended from the same ancestors - mammals that inhabited the earth millions of years ago, but were not strictly land animals, but rather loved to hunt and live in the water. These are mesonychids - omnivorous creatures with hooves like those of horses and cows, with a predatory, wolf-like appearance. According to approximate data, mesonychids lived for more than sixty million years, and they inhabited the modern continent of Asia, part Mediterranean Sea(in ancient times it was the Tethys Sea). These animals most likely ate any small aquatic animals and any fish that then inhabited the numerous swamps off the coast.
And due to the fact that mesonychids spent most of their lives in any body of water, their appearance gradually began to develop in width, streamlined, their limbs turned into fins, while the hair on the skin began to disappear, and underneath it, thick subcutaneous fat developed and intensified. To make it easier for animals to breathe, the nostrils ceased to fulfill their original function: in the process of evolution, they became a vital organ for the animal, since creatures could breathe through them, and all thanks to their displacement to the top of the head.
Even for a long time It was believed that the ancestors of cetaceans, including dolphins, were indeed mesonychids; however, they “borrowed” most of all from hippopotamuses, and this is proven by numerous molecular studies. Dolphins are not just descendants of these artiodactyls, they are also deeply similar and part of their group. Until now, hippos and hippos live mainly in water; they only spend a couple of hours on land to eat. That is why scientists suggest that hippos are one of the evolutionary branches of cetaceans. It’s just that whales went further than hippos, they completely abandoned life on land and completely switched to life in the water.
And if the relationship between hippopotamuses with hooves and legless cetaceans seems strange to you, then we would like to give another version of the taxonomy, for example, land animals with 4 legs that evolved from fish. It’s just that we shouldn’t be surprised that long before our civilization appeared, the evolution of dolphins proceeded so rapidly.
Description of dolphins
Dolphins are large waterfowl that breathe air, unlike fish, whose breathing function is provided by gills. Sea dolphins are in the water all 24 hours, and this is where they give birth to little dolphins. Since the female feeds her babies herself, they are therefore warm-blooded creatures, mammals.
Unlike their relatives, whales, dolphins are more beautiful creatures. Apart from sharp teeth, no sinister intrigues can be found in their intelligent and friendly gaze. So, an adult dolphin can be 2.5 meters long and weigh only three hundred kilograms. Whereas it can be nine meters long and weigh eight tons. Males are always larger than females, by at least 20 centimeters. They have more than eighty teeth. The color of the body and fins is black or gray, while the belly is white.
The largest body cetacean dolphins have a brain that is amazingly awake all the time while the dolphin is sleeping. The brain allows the animal to breathe all the time, even when it is sleeping: this way the dolphin will not drown, because the supply of oxygen for cetaceans is very important for life.
Scientists have called dolphin skin a natural miracle. This is their wealth! When dolphins calmly dampen the water turbulence, when the body needs to slow down a little.
This is interesting!
The creators of submarines have long looked closely at how dolphins swim. Thanks to the dolphins, the designers were able to create an artificial skin for the submarine.
Dolphins: what they eat and how they hunt
shellfish, different kinds fish and other aquatic animals are the food of the dolphin. Interestingly, dolphins can eat a lot of fish in a day. Dolphins hunt fish in schools, and each member of the school can eat up to thirty kilograms. All this is due to the fact that dolphins are animals that, when too low temperature conditions oceanic or sea water(below zero degrees Celsius) you must always maintain your own temperature so that it is optimal. And warm-blooded dolphins are helped in this by thick subcutaneous fat, which is constantly replenished through huge amounts of food. That is why dolphins are always on the move, hunting, and only at night allow themselves to rest a little.
A school of dolphins can very quickly catch up with a school of fish, because in the sea these animals are aces. If the dolphins are already close to the beach, they instantly form half rings around the fish in order to push their future food to the shallow water and eat there. As soon as dolphins capture schools of fish, they do not immediately rush at them, but then continue to keep them in a circle so that they do not swim away, and each member of the pod can have lunch or dinner with their favorite food.
To see dolphins, just look for a school of fish. These cetaceans will definitely live where there are a lot of fish. In summer, dolphins can be found in abundance in Azov, when mullet and anchovy move to the sea to feed. Dolphins also swim close to the Caucasian shores in early autumn, when fish begin to migrate in herds.
As you may have noticed, it is rare to see one dolphin in the ocean, since these animals are very friendly, love to live in schools, hunt together, and even dolphins can jump beautifully and perform their tricks together with their comrades. Be that as it may, dolphins never got along with killer whales. There are also still poachers who hunt these friendly earthly creatures. Despite everything, dolphins trust people and even know how to communicate not only with each other, but also with other animals. They will never leave their comrades in trouble. And in case of severe danger, they can even help a person. There are so many legends and stories in the world about dolphins saving people’s lives. Some even watched as dolphins pushed boats that were carried away by the winds to the shores.
Dolphin breeding
Unlike other inhabitants water world, dolphins are the only ones that are born with tails, not heads. And that's true. Loving mothers do not leave their babies even two or three years after birth.
This is interesting!
Dolphins are incredibly sensual and compassionate animals. A little dolphin, even after it becomes a completely independent adult male or female, never leaves its parents under any circumstances.
And not only do dolphins experience great affection and love for their own fellow creatures, but even for whales, other animals (they don’t like killer whales) and for people. Once a female and male have babies, they never leave each other, even after having numerous babies. Who else but dolphins know how to love their young, tenderly and lovingly treat them, teach them, take them hunting, so that soon the children themselves know how to hunt fish.
This is interesting!
If dolphins are hunting and sense danger, they lead their babies behind, but if there are no external threats, the baby dolphins calmly swim in front of their parents. Interestingly, after the cubs the females swim, and then the males - the protectors.
Relationships with people
Since each dolphin lives in peace and harmony with its fellow tribesmen and whales, it behaves accordingly. The sense of help in these animals is particularly developed. They will never leave a sick dolphin to die; they will even save a choking person at sea if, by a lucky chance, they find themselves nearby. Dolphins can hear a person’s cry for help far away, since their hearing is very developed, as is their brain.
The fact is that dolphins spend all their time in the water, which is why their vision is weakened (weak water transparency). Then, the hearing is perfectly developed. The dolphin uses an active location - the hearing is able to analyze the echo that occurs when it produces characteristic sounds from any objects surrounding the animal. Based on this, the echo tells the dolphin what shape and length the objects around him are, what they are made of, and in general, what they are. As you can see, hearing fully helps fulfill the visual role for the dolphin, which does not prevent this peace-loving creature from feeling complete in such a complex world.
It's easy for a person to tame a dolphin. Fortunately, like a dog, the animal is easy and simple to train. All you have to do is entice the dolphin with a delicious fish. He will perform any somersault for the public. Although dolphins have one flaw, they can forget any trick very quickly if a person forgets to feed them on time.
Why do we all treat dolphins differently than other animals? Looking at these cute and funny creatures, you forget about how huge these animals are, and how, despite their size, they are the only cetaceans that can safely be classified as the best “friends”.
Dolphins are like grandmothers on a bench, overly curious. They swim up to a person with interest, flirt with him, throw a ball, and even smile, although few people notice this. They are designed to smile at us, laugh with us. Well, we can’t call a dolphin’s face a muzzle, the smile on their face is cheerful and friendly – that’s what attracts us to them!
Dolphins love us, we love them. But there are... heartless people who, for the sake of profit, forget about humanity and kill these peaceful creatures. In Japan, dolphin hunting is amazing! They don't even think about talking about sympathy for dolphins. On other continents, dolphins are placed in dolphinariums for the amusement of people. In cramped conditions in which they do not live longer than five years (for comparison, in nature, dolphins live up to fifty years).
This is interesting!
The Indian state has become the fourth state in the world to ban the construction of dolphinariums. The first countries to ban keeping these cetaceans in captivity were Asian Chile, Costa Rica, and Hungary. For Indians, dolphins are the same as a person who also has the right to freedom and life in nature.
Dolphin therapy
The history of the great friendship between sea dolphins and humans goes far into the past, even before scientists began to call these animals dolphins. Researchers of the body language of cetaceans have come to the conclusion that they have developed verbal communication abilities in the same way as humans. If a mentally ill child, an autist, spends a lot of time with dolphins and “communicates” with them, then this will have a beneficial effect on him. The child begins to smile and laugh. The British talked about this back in the 70s of the last century. Subsequently, dolphin therapy began to be actively used to treat not only mental and neurological diseases, but also many physical ones. Swimming with dolphins together is useful, you can relieve stress, strong headache, neuralgia and even rheumatism.
Abnormalities in behavior
All of you have probably seen this picture on the news or on the Internet, when the beaches are full of dolphins that have stranded themselves. Often they are thrown out on their own because they are very sick, injured, or poisoned. Dolphins clearly hear sounds from the shore, which are very similar to cries for help from their fellows. Therefore, upon hearing such a cry, dolphins rush to the shore to help, and often find themselves trapped.
Dolphins, perhaps one of the most amazing creatures on our planet. The Polynesians and ancient Greeks had legends that dolphins were once people and have not yet forgotten about it. Sailors, no matter what flag they sailed under, considered meeting dolphins a happy omen. Over the past two centuries, a huge number of versions have been put forward about what dolphins are. Some researchers consider them highly developed animals, others - an alternative form of civilization, and still others - people from outer space. Attempts to “establish contact” with dolphins have been known since ancient times. However, most of them are broken by the language barrier...
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Dolphins are excellent swimmers and divers. Scientists have long tried to find an explanation for Gray's paradox: a swimming dolphin spends half as much energy as required by the laws of hydrodynamics. Not long ago it became clear that the secret of such economical energy consumption is the special structure of the skin, which dampens the turbulent turbulence that occurs during movement.
A number of experiments were carried out with coatings for ships and submarines, and fuel consumption for prototypes dropped dramatically. Dolphins also use their oxygen reserves extremely sparingly. Compared with person, which uses only 20% of the oxygen it inhales, the dolphin is able to absorb up to 80%. Some of the oxygen is used immediately, and some is stored in the blood and muscles. This is what allows dolphins to carry out water up to half an hour.
The aquatic environment has changed not only the appearance of dolphins, but also their perception system. Unlike terrestrial animals, for which vision is the main thing, aquatic animals, as a rule, are forced to rely on other senses, primarily hearing. Dolphins can perceive a much wider range of sound frequencies than humans. The human ear perceives sound waves with a frequency of up to 15–20 kHz, the dolphin’s ear – up to 150–200 kHz. But that is not all. His hearing is 100 times more sensitive than human hearing, and his ability to distinguish sounds and decompose the general sound background into component frequencies is 3-4 times greater than human capabilities.
Each dolphin in the ocean has its own name, which it responds to when its relatives call it. He receives it immediately as soon as he is born, and it is a characteristic whistle lasting 0.9 seconds. Dolphins not only call each other by name, but also introduce themselves when meeting strangers. And identifying a relative by voice without seeing him is a piece of cake for them.
Dolphins are mammals from the family of toothed whales of the cetacean order. There are about forty species of these animals on the planet, and they can be seen anywhere in the World Ocean. Most dolphins prefer to live in tropical and subtropical latitudes, but there are some that like colder waters, so you can see them near the Arctic, and some species are found both there. For example, although the white-beaked dolphin lives mainly in North Atlantic, it can often be seen off the coast of Turkey.
Most members of the family (for example, bottlenose dolphins, white-beaked dolphins) are marine inhabitants, but there are four species that prefer to live in fresh river or lake water. The river dolphin lives in Asia, as well as in the waters of the South American Amazon and Orinoco rivers.
Unfortunately, if previously representatives of this family were often encountered, now the river dolphin, due to loss of habitats and pollution, environment, a decrease in the amount of food and small populations has practically disappeared and is listed in the Red Book.
Description
The length of dolphins ranges from one and a half to ten meters. The smallest dolphin in the world is Maui, which lives near New Zealand: the length of the female does not exceed 1.7 meters. Large inhabitant depths of the sea The white-faced dolphin is considered to be about three meters long. The most major representative is a killer whale: the length of males reaches ten meters.
It is worth noting that males are usually ten to twenty centimeters longer than females (the exception is killer whale dolphins - here the difference is about two meters). They weigh on average from one hundred fifty to three hundred kilograms, the killer whale weighs about a ton.
The backs of sea dolphins can be gray, blue, dark brown, black and even pink (albinos). The front part of the head can be either plain or white (for example, the white-faced dolphin has a white beak and the front part of its forehead).
In some species, the front mouth is rounded and there is no beak-shaped mouth. In others, small ones, the head ends in an elongated mouth in the shape of a flattened “beak”, and the mouth is shaped in such a way that it seems to people watching them that they are always smiling, and therefore they often have an irresistible desire to swim with dolphins. At the same time, the impression is not spoiled even by the huge number of teeth of the same cone shape - dolphins have about two hundred of them.
Thanks to their elongated body and smooth, elastic skin, these animals hardly feel the resistance of the water while moving. Thanks to this, they are able to move very quickly (the average speed of a dolphin is 40 km/h), dive to a depth of about one hundred meters, jump out of the water nine meters in height and five in length.
One more unique feature of these marine mammals is that almost all species of dolphins (with the exception of the Amazon river dolphin and several other species) see well both underwater and above the surface. They have this ability due to the structure of the retina, one part of which is responsible for the image in the water, the other - above its surface.
Since whales and dolphins are relatives, like all representatives of cetaceans, they are quite capable of staying under water for a long period. But they still need oxygen, so they constantly float to the surface, showing their blue muzzle and replenishing air reserves through the blowhole, which closes under water. Even during sleep, the animal is fifty centimeters from the surface and, without waking up, swims out every half a minute.
Way of life
Dolphins live in schools and do not tolerate loneliness very well. Although they do not have a leader, they carry out all actions in coordination: they hunt together, raise children, have fun, performing amazingly beautiful jumps one after another.
The dolphin is considered one of the most intelligent mammals on our planet: the weight of its brain is 1700 grams, which is three hundred grams more than a human, and the convolutions in the cerebral cortex are also twice as large. This explains their highly developed social consciousness, ability to sympathize, readiness to help sick and wounded relatives, as well as drowning people.
Dolphins help quite actively: if one of the members of the pod is injured or barely stays afloat, they support him near the surface so that he cannot drown and choke. They do the same in relation to a person, also helping to get to the shore. Some scientists explain why dolphins do this by caring for the population: each individual in the pod is valuable - and everything must be done to save its life.
Language
Animals use gestures to communicate (turns, jumps, various styles swimming, head, fins, tail), as well as voice: the sounds of dolphins are about 14 thousand signals, and everyone has heard about the songs of dolphins. These unique animals are capable of perceiving vibration frequencies of up to 200 thousand per second, while the human ear is up to 20 thousand.
They are also four times more capable of analyzing dolphin sounds by separating frequencies from each other (to find out why dolphins have these abilities, see Lately a lot of research is being done). Communication occurs mainly with the help of ultrasound (it is especially convenient for them to use it to transmit sound over vast distances).
Dolphin songs are not only ultrasound: the sounds of dolphins often sound at a medium frequency and are expressed by clicks, creaks, and whistles (studies have shown that they perceive their speech as hieroglyphic pictures).
There are two types of dolphin sounds:
- Sonar or echolocation - animals hear the echo of a beating sound and identify it;
- Whistling or chirping - these sounds of dolphins are used for close communication with relatives and the animals express their emotions with them. Scientists counted about 186 different types“whistles”, which, like human speech, contain sounds, syllables, words, phrases, paragraphs, context and dialect.
Nutrition
Dolphins' diet is based on fish, squid, and shrimp (some dolphins in the ocean are quite capable of diving to a depth of 260 kilometers to catch their favorite prey); killer whales eat marine mammals and birds.
They catch fish in different ways. Sometimes the whole school of dolphins searches for her, sometimes in a separate group or they send a scout to look for her.
If the hunt takes place in the open sea, dolphins surround a large school of fish, crowding them into a heap, after which they take turns diving there and feeding. If they are fishing near the shore, the strategy is somewhat different: a school of dolphins drives the schools towards land, after which the fish are easily caught in shallow water.
Reproduction
The ability to reproduce in females appears between the fifth and twelfth years of life, in males - between the ninth and thirteenth. Their pairs are unstable and the animals change partners every time.
Exactly how long pregnancy lasts has not been established; the period is estimated to range from ten to eighteen months. When giving birth, the female is very close to the surface so that, as soon as the baby is born, she raises her tail high, giving him the opportunity to take a breath of air before falling into the water.
Usually one baby is born, about half a meter long, and until six months the mother feeds it with milk and protects it. Newborn babies usually do not fall asleep during the first month of their life and do not allow their mothers to sleep, swimming around them and surfacing every thirty seconds, forcing them to be constantly on alert.
Relationships with people
People and dolphins have a long and complex history: until recently, animals were actively hunted, which led to the complete and partial extinction of some species. After fishing was banned, the situation got better, but a new trend emerged: catching these animals for show (especially since they are very smart and catch everything on the fly) and giving people far from the sea the opportunity to swim with dolphins. It should be noted that the idea is not the best, because if in natural conditions the inhabitants of the sea live from thirty to fifty years, in captivity - only seven.
Their rapid death is primarily influenced by an overly passive lifestyle, even despite constant training to participate in the show, extremely limited space and water quality: the lack of a full range of nutrients and minerals they need.
Recently, people and dolphins have learned to interact better (primarily this concerns humans, since these animals are sociable, friendly and peaceful). Moreover, communication with these mammals benefits almost everyone: by giving the opportunity to listen to the songs of dolphins, communicate, stroke the blue back, feed fish, swim with dolphins, psychotherapists and doctors effectively use them to treat diseases in children such as cerebral palsy, early childhood autism, etc.
