Since ancient times, dolphins have been considered intelligent and friendly creatures who willingly communicate with people and, at the first call, come to their aid. Last but not least, this stereotype arose because of the "smiling" face of dolphins. And the dolphin Flipper helped shape it to modern Westerners. This is the hero of the American television series of the same name, who pulled his human friend out of various troubles. In recent decades, people increasingly want to swim with wild dolphins. But according to scientists, it can be unsafe for either one or the other. Let's see if it is worthwhile to closely associate with wild dolphins?
In the myths of the ancient Greeks, and later the ancient Romans, gods, demigods and nymphs ride on dolphins. Dolphins saved the heroes of several myths drowning in the sea from death. According to one of the stories about the lord of the seas Poseidon, when he decided to marry, the girl who liked him got scared and fled. The dolphin, one of the messengers of God, persuaded her to return and marry her. In Hindu mythology, the goddess of the river Ganges rides a dolphin. In the legends of the peoples of Oceania, dolphins can change their appearance, turn into humans and conceive children with earthly women.
The relationship of dolphins with humans has been repeatedly mentioned by both ancient authors and writers or travelers of a later time. Most often, it was about joint fishing, during which dolphins drove the fish to the people standing in the sea, or drove it into the nets. Part of the catch went to the fishermen, and part to the dolphins. Pliny the Elder mentions the joint fishing of an unknown species of dolphins and fishermen during the migration of mullet in the Mediterranean Sea. A similar process is described by an English traveler observing Australian aborigines. River dolphins living in the Amazon, Ganges or Yangtze, and marine species off the West African coast or the coast of Brazil took on the role of fish beaters.
The ancient Roman author Pliny the Younger describes the case of "friendship" of an unknown species of dolphin with a boy, a resident of a city on the coast of North Africa. The dolphin's games and tricks attracted crowds of visitors to the city, making it difficult for locals to be in their hometown. In the end, the visitors so worried the townspeople that they eliminated the cause of the excitement - they killed the dolphin.
But how does the relationship between people and dolphins develop beyond myths and legends?
Up. A female named Bebe from the Miami Aquarium as Flipper the dolphin. Down below. Still from the television film "Flipper", 1964.
Dolphins in the home circle
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Most often, in various kinds of stories about the relationship between people and dolphins, we are talking about the bottlenose dolphin or bottlenose dolphin (Tursiops truncatus). They live off the coast and are a widespread and well-studied species of dolphins. Therefore, by default we will mean the bottlenose dolphin.
Bottlenose dolphins live in flocks of two to 15 individuals. Their composition is inconsistent and varies depending on age, gender, family ties or season. They usually consist of females with newborn cubs, or adolescents of different sexes. Several flocks can temporarily unite in "super flocks", the number of which can reach thousands of individuals.
Adult males from some Atlantic populations form "alliances". This is how dolphin observers call them, although judging by their occupation, they should rather be called "gangs". They consist of two or three individuals that follow the adult females and force them to swim with them. Two or three "unions" are often combined into "super unions" competing for females. Researchers suggest that this is how males guard and intimidate receptive females with whom they can mate.
First, the "allies" catch the female: they circle around her, preventing her from swimming away. So that she does not try to escape, the males bite her, beat her with their tail or other parts of the body. The researchers described a case where the pursuit and intimidation of a female lasted more than an hour. During this time, the victim and the pursuers swam seven kilometers. The female manages to escape from the annoying "gentlemen" only in one of four cases. Sometimes "unions" of males beat off captured females from each other. At the same time, they act directly strategically: they unite against competitors two by two. And once scientists noticed how a gang of two males and a lone dolphin fought for a female. As a result, the female remained with her “allies,” and the male lost consciousness during the struggle, but nevertheless remained alive and eventually swam away.
Researchers have repeatedly described (1, 2) cases of infanticide in several populations of bottlenose dolphins. Marine biologists once observed an attempt by two adult males to kill a newborn calf. Fortunately, his mother saved him. In other cases, scientists saw the consequences - the dead bodies of dolphins washed up on the shore with traces of internal damage that led to the death of animals. These included bruises of soft tissues and internal organs such as the liver or lungs, broken ribs, and injuries to the skull. The nature of the injuries indicated that the cubs did not fall under the ship's propeller or in the fishing nets, but were killed, and not by predators, but by relatives.
The cause of infanticide in bottlenose dolphins is likely the same as in some other species, such as lions or gorillas. Females of these species breed relatively rarely due to the fact that they take care of the young for a long time. If the male kills them, the female becomes receptive again, and he has a chance to mate with her. Pregnancy in bottlenose dolphins lasts 11-12 months, and then they feed the cub for at least a year and a half. Therefore, dolphins bring offspring every few years. Not surprisingly, some male bottlenose dolphins want to shorten this period.
Bottlenose dolphins do not always have a good relationship with their relatives either, at least in some Atlantic populations. For example, scientists observed how three young bottlenose dolphins off the coast of southern Brazil held in place a calf of Sotalia guianensis, a species of dolphins living in estuaries and off the coast of South and Central America. Bottlenose dolphins did not allow the cub to swim away and drove off two adults who came to the rescue. All participants in the skirmish survived. And the researchers theorized that bottlenose dolphins used a cub of Sotalia guianensis as a training projectile and practiced their fighting skills.
Bottlenose dolphins, from another population off the northeast coast of Scotland, “trained” on local porpoises, which are smaller in size than dolphins, and often ended up killing small cetaceans. However, bottlenose dolphins usually get along with other species of dolphins, and only sometimes arrange fights with them over food or females.
Friendly but lonely
There are numerous modern cases of "friendly" relations between people and dolphins. Most of them are loners who grew up near the coast, or sailed to the "fish" places near the coast as adults. Gradually, they first get used to people on boats and ships, and then gradually began to contact with people in the water. The friendly dolphin becomes known outside the district, people from other cities or regions come to see and swim with it, and in the end, the press finds out about the new "tourist attraction". Surprisingly, these individuals often do not seek to contact dolphins of their own kind, and if a flock is nearby, they do not seek to join it.
Wild dolphins and surfer off the coast of Southern California.
Unlike lone dolphins, dolphins in a flock are far from being so friendly towards humans. So far, one case of long-term "friendship" is known - between people and a group of animals that lived in Shark Bay off the coast of Western Australia. This took place in the late 1970s and 1980s. A group of about seven animals sailed to the shore, usually in the morning, where tourists with fish were waiting for them. Dolphins (mostly females with calves) allowed themselves to be touched; some of them stayed near the coast for many hours. Authorities later limited the number of tourists allowed to feed the dolphins. During feeding, they were forbidden to touch the animals.
Solitary dolphins, who willingly communicated with people and who were given nicknames, met off the coast of Great Britain, Mediterranean countries, Australia and New Zealand, the USA, and the Caribbean. Animals rode the waves with surfers or swam behind motor boats and rode the waves they created. Some of the dolphins allowed humans to be close to them in the water, pet themselves, swim with them, or even on their backs.
Mutually dangerous
But not all animals liked this familiarity. Some of them simply floated away, and some clearly showed that they did not want to be near people. So, the press reported on dolphins that attacked people swimming nearby, prevented swimmers or surfers from returning to the shore, and even tried to drown a swimmer. A New Zealand researcher who studied spinning dolphins was once confronted with an angry adult male threatening her at her presence. But fortunately it all ended without injuries, as she knew how to behave in a similar situation.
A bottle-nosed dolphin named Tião, who lived off the coast of Brazil, was so annoyed by the intrusive attention of people who wanted to communicate and take pictures with him that he sent 30 people to the hospital, one of them later died of internal bleeding. But it was rather an extreme case: people themselves provoked the dolphin. Despite the fact that the tourists were told how to behave with him, they tugged at his fins, pushed, climbed onto his back and even tried to shove ice cream into his blowhole.
Occasionally dolphins show unprovoked sexual aggression. Researchers have repeatedly recorded cases when males behaved aggressively towards male swimmers and tried to mate with women in the water. Isolated cases of similar behavior (aggression towards swimmers) were observed in dolphins.
But dolphins are not much more dangerous for people, but people for dolphins. Motor boats, which bring tourists to the dolphins, prevent the animals from sleeping. Statistics show that "friendly" lone dolphins living near the coast communicate with people for several years, but eventually disappear or die. Some get caught in nets and suffocate, die in collisions with ships, or fall under the propeller.
People kill some of them on purpose. For example, the male Tio, who killed one of the people who bothered him, disappeared after a while, presumably he was killed in revenge for the death of a person.
This is not to say that all dolphins are aggressive and at the first opportunity they attack individuals of other species or humans. Examples can be cited when dolphins swam peacefully next to people, making no attempt to attack them, and sometimes even saved their lives.
So, in August 2007, a flock of dolphins rescued surfer Todd Indris from a great white shark off the coast of California. He was catching a wave in Monterey Bay off the coast of California when he was attacked by a great white shark. The predator managed to bite him twice (the wounds were dangerous and he had to heal for several months). But suddenly a flock of dolphins came to the rescue of Todd, which pushed the shark away from him and formed a protective ring around him, making it possible to get out on the shore.
But it is hardly possible to expect that such stories will always end happily. Trevor Spradlin, an employee of the American National Marine Fisheries Service (USA), said that he and his colleagues knew dozens of cases when dolphins bite people, including those who fed them. “We don't think people need to stop going to the beach, or go to see dolphins,” he said. - But you need to do it carefully and taking responsibility for your actions. Lovers of marine animals should treat them the same way people on safaris or birdwatchers do - with great respect."
Author: Ekaterina Rusakova
