Sleep is a natural and indispensable need for all mammals on the planet. However, the truth about dolphin sleep has long been a mystery to researchers. Do dolphins really sleep with one eye open? It was once believed that these animals rest in "snatches" between breaths of air or even are deprived of sleep at all. Both last assumptions turned out to be wrong. Nowadays, scientists already know the true answer to the question of how dolphins sleep.
Interesting information about dolphins
Dolphins - warm-blooded mammals from the order of cetaceans - have rightfully won fame for some of the most mysterious creatures on Earth. The characteristic dolphin nickname - "People of the Sea" - emphasizes the fact that their intellectual potential is so great that they are considered smarter and smarter than all the other animals of the planet.
Dolphins live in packs. Mutual assistance to each other is developed among these creatures, sometimes reaching self-sacrifice. Dolphins are able to talk, issuing about ten variations of various sounds at both normal and ultrasonic frequencies. In addition, they have a unique hearing, which operates on the principle of sonar and allows you to determine not only the distance to the object or object, but even its size and shape.
Dolphin is considered one of the fastest marine animals - in water it is capable of speeds up to forty kilometers per hour! These animals are predators, they feed mainly on fish. The dolphin has a lifespan of about thirty years.
In the wild, many dolphins are willing to contact people. A dolphin, rescuing his relative from danger, will swim in the same way to help a person. He will pull the drowning man to the shore, drive the shark away from him, and show the way for the sailors. This fact has long been proven, but the essence of this phenomenon has not yet been able to explain.
Do dolphins sleep?
Sleeping with dolphins is vital - just like all other mammals. However, it is special in these animals. Observations, as well as studies of the bioelectrical activity of the brain, have revealed a very definite picture of how dolphins actually sleep.
In order not to drown during sleep or become a victim of a predator attack, these marine mammals sleep "half". One hemisphere of the animal’s brain during sleep receives a complete rest, while the other continues to stay awake, controlling what is happening around and responsible for respiratory function. That is why dolphins sleep with one eye open: if the right hemisphere rests, the left eye is closed, and vice versa. Such a dream takes about six or seven hours a day. And when the dolphin wakes up, both hemispheres begin to work.
How dolphins sleep
Unusual at first glance, the peculiarity of the "half" dream of a dolphin does not prevent him from going through all phases, from fast to deep, and at the same time ensure the animal a good rest. Scientists closely watched how dolphins sleep and revealed common patterns. This always occurs at a shallow depth, near the very surface of the water. Due to the high content of adipose tissue in the body, dolphins very slowly descend. Every now and then the animal, being in a dream, strikes the water with its tail and floats to the surface in order to breathe air. After that, it again slowly sinks to a depth.
Dolphin's breath in a dream
Sensing a change in the environment when it dives to the surface , the dolphin opens its breathing (nostril). He breathes very quickly: due to the structural features of the respiratory tract, he is able to inhale and exhale simultaneously. While under water, the breather remains securely closed tight valve.
Newborn dolphins do not sleep for a month!
Studies have proven: the assumption that dolphins never sleep is a myth. However, another curious fact was discovered. Scientists at the University of California at Los Angeles found that newborn cubs of dolphins and whales do not fall asleep at all during the first month of their lives! In addition, babies also force their mothers to remain active all this time ...
Tiny dolphins are constantly moving, floating to the surface for air every three to thirty seconds. And only after a month in their daily routine short sleep periods begin to appear, which are gradually approaching the norm characteristic of an adult animal.
American biologists have suggested that this behavior reduces the risk of dolphins and whales being eaten by predators and also allows them to maintain a stable body temperature. In this regard, they raised an interesting question about the presence of a certain reserve in the body of mammals, which allows them to do without sleep for a long time, without experiencing any harm to their health.