Dolphins are smart and friendly, but there is also a dark side to them that will make your hair stand on end. Dolphins are intelligent and friendly mammals that love to perform different tricks. All of the above is true, but dolphins are also seen in sexual harassment, incest, and infanticide.
Dolphins are smart. Anyone who has seen them perform incredible stunts knows this.
For those of you who doubt it, a myriad of studies have been conducted to examine their cognitive abilities.
In most cases, dolphins of the most common and well-known species were studied - bottlenose dolphins, or large dolphins.
Dolphins living in captivity are able to remember whistles in different tones for many years, and sometimes decades.
A classic scientific work on dolphins, published in 1984, presents the results of an experiment in which scientists trained a female bottlenose dolphin named Akeakamai to mimic (in a whistle mode, as the authors write) computer-generated sounds.
The beeps emitted by the electronic device and those answered by Akeakamai were remarkably similar.
Then biologists began to bind sounds to objects like a hoop, pipe, frisbee, or ball.
Promotional video:
Akeakamai quickly calculated this connection and made a sound that indicated the vocalization of each of the objects. In essence, she has learned a new vocabulary.
Wild dolphins are showing comparable achievements. Each of them have their own signature sound, which serves as a kind of name for them.
When scientists recreated these signals with a computer synthesizer, the dolphins responded as if they knew who was calling them.
On top of that, they remember each other. As a result of scientific research carried out in 2013, it was discovered that dolphins can remember a particular sound ("whistle phrase") for many years, and sometimes decades.
In one case, a female named Ollie from Brookfield Zoo (about 20 kilometers west of Chicago, Illinois) responded vividly to a recording of the voice of another dolphin, Bailey, in Bermuda - despite the fact that they had not seen each other for over 20 years.
Even more striking, in 2001, two bottlenose dolphins successfully passed the mirror test at the New York Aquarium.
Scientists used a "black Entre non-toxic ink marker" to draw geometric shapes of various shapes on the bodies of animals, which served as their special features.
After that, the dolphins swam up to the mirror and studied themselves for a long time. This suggests that dolphins can recognize themselves - at least to some extent, which very few species of animals are capable of (in particular, great apes and other apes, elephants and African gray parrots - Ed.).
The brilliant brain capabilities of these marine animals led to the emergence of a kind of dolphin cult, both within the framework of the New Age movement (mystical, occult and esoteric practices, which boomed in the 1970s) and beyond.
However, scientists have discovered a much darker side to dolphins' nature. It turned out that they behave quite differently than Flipper (miracle dolphin, friend and rescuer of people from the series of the same name - Ed.)
“They are very smart, but just like humans, they can be nasty and cunning,” says Richard Connor, at the University of Massachusetts at Darmouth and co-director of the Dolphin Research Association.
Gang rape?
When the mating season comes, a fierce struggle for females arises between them. In the 1980s, Connor and his colleagues were the first to document that male dolphins aggressively harass fertile females in Shark Bay in Australia.
"Harassment begins when two or three males catch a female," they wrote in 1992.
Females often tried to escape from males, but they only succeeded in one out of four cases.
Males violently attack their chosen one. In one of the observed cases of such a "hunt" the chase lasted 85 minutes, the hunters and prey covered a distance of seven kilometers.
In the course of further observations, it became apparent that the composition of these associations of males can be very variable.
Small teams of males were usually part of larger “super-alliances”, with up to 14 members.
It also turned out that the females were not at all eager to participate in these mating games.
“Male aggression against females was expressed in pursuit, tail banging, head butting, swooping, and biting and biting females,” Connor and colleagues wrote in a 1992 article.
Females often tried to escape, but they only succeeded in one in four cases.
“Throughout the year, females were harassed by males from many alliances, and in various months of the year - over several months,” wrote Connor and his colleagues.
The deadly sin of infanticide
Females' determined attempts to get rid of the harassment of dominant males may be another ominous truth about dolphins.
Baby tossing sounds like a fun game, but it can also be the way that adult males kill unrelated pups to death.
During 1996 and 1997. 37 young bottlenose dolphins were thrown onto beaches in Virginia.
On a superficial examination, it might have seemed that everything was in order with them, however, as a result of the autopsy, severe injuries caused by a blunt object were found.
Mainly head and chest injuries were identified, "numerous rib fractures, lung tears, and soft tissue bruises were conspicuous." These data are contained in a scientific paper published in 2002.
There is a lot of evidence that adult dolphins are to blame for the death of young animals.
In particular, one of the scientists observed several behavioral events, bashfully labeled as "tossing cubs" in coastal waters off the city of Virginia Beach.
Baby tossing sounds like a fun game, but it can also be a way for adult males to slaughter unrelated pups to death so that their mothers return to estrus.
In 2013, scientists saw a male dolphin attack a newborn calf, although this time it appears the baby was able to swim away.
If infanticide is a direct and clear threat in the dolphin community, then the female may be prudent by trying to mate with many males from different alliances, Connor says.
Thus, males will not know which of them will be the father of her cub, and the likelihood that they will kill him is reduced.
“She doesn't want to be monitored,” he says.
There is another surprise in the mating behavior of dolphins.
In 2004, a study of heredity within the dolphin population at Shark Bay revealed that these mammals occasionally practice incest.
One male, known as BJA, became a father in 1978, and 15 years later, in 1993, mated with his own daughter.
“We saw males courting their mothers in a group of three partners,” says Connor.
Along with this is a study published in 2010. It confirms that the incidence of incest in a particular population is higher than random.
You thought sharks were bad.