Grey dolphin: features of the species

2024 Author: Henry Conors | [email protected]. Last modified: 2024-02-12 02:47

Some people believe that dolphins are superior to humans in their intelligence, their brains are colossally developed. They can communicate with each other from afar using ultrasonic waves. The gray dolphin is a mammal of the cetacean order.

How to recognize a gray dolphin?

From other species of dolphins, this one is enormously different. The gray dolphin does not have a so-called beak, its physique is powerful and massive, the body tapers towards the tail, and the tail itself is narrow. The powerful forehead is steeply raised from the tip of the upper part of the snout, the head is rounded, neat. The incision of the mouth does not extend over the entire muzzle. A small concave groove located on the head distinguishes the gray dolphin from all other brethren. A description of its color cannot be given unambiguously, since the color of the body changes greatly with age. The back of the dolphin is gray or dark gray, the abdomen is light, with age, white spots on the body become larger. He seems to be turning gray, covered with white. The entire surface of the body is riddled with scars from wounds inflicted by mollusks or relatives. When communicating with each other, these dolphins are often aggressive and bite.

The weight of an adult can reach five hundred kilograms. Body size from tiptail to the beginning of the muzzle - from three to four meters. Gray dolphins are the fifth largest in their family. They have up to seven pairs of teeth, all located on the lower jaw, the upper gum is smooth. Dolphin teeth protrude half a centimeter forward from the gum. Because of the upper fin, a gray dolphin can be mistaken for a killer whale until it emerges from the water.

What do dolphins eat?

This mammal prefers to feed at night, not because there is not enough time during the day, but because their favorite delicacy - squids - only approach the surface of the water in the dark. Everything that dolphins eat is found in the water - these are mollusks, crustaceans and a variety of fish. By eating these creatures, the described animals significantly affect their distribution and quantity.

Distribution

Grey dolphins are distributed throughout the world in free waters and along coasts. They are not found only on the west coast of Africa, in some waters of South America. In Russian waters, the gray dolphin is a rare sight, mostly found closer to the Kuril Islands. Their exact number is unknown, the approximate number of individuals in total is more than four hundred thousand.

Reproducing and raising cubs

Dolphins live up to thirty-five years. The age at which females mature for procreation is 8-10 years. Males are not limited by years, their sexual maturity determines the size of the body - from two and a half meters. Hatching graydolphins cubs from a year to fourteen months. Babies at birth weigh about twenty kilograms, they can swim on their own. The mother feeds the children with breast milk until they reach the age of one and a half years. In the east of the Pacific Ocean, the peak of dolphin births occurs in winter, and in the east - in summer and early autumn. Dolphins are social creatures, they are very sociable, they live in groups and the cubs are taken care of by the whole flock. If the baby is in trouble, no matter whose, you need to protect. Everything, like people.

On the brink of extinction

The gray dolphin is very rare in Russian waters. The Red Book of the USSR mentioned this species on its pages, it was protected. At the moment, the gray dolphin is listed in the IUCN-96 Red List, and so is in the Red Book of Russia. These individuals are protected by the state, a large fine is provided for their capture. The gray dolphin has no value for humans: it is inedible, the skin is not suitable for sewing. What could threaten this animal?

The first is the depletion of fish stocks in dolphin habitats. Fishermen, like dolphins, know when and where to fish. In Japan and Sri Lanka, dolphin meat is eaten, so up to two thousand individuals are eaten in these places a year. Anthropogenic sounds passing through the oceans are detrimental to deep-sea inhabitants, including dolphins. These noises, which are picked up by sensitive animals, cause decompression sickness. The disease is fatal to all dolphins. Rising sea levels and rising water temperatures can alsocause the extinction of many species, including the gray dolphin. With climate change, they will have to migrate, which will affect conditions and habitats, food and, consequently, the number of survivors.

Man does not take the most plausible part in the life of dolphins, throwing industrial waste and ordinary garbage into the sea. Dead individuals were discovered by Japanese scientists, at the autopsy of which it turned out that their stomachs were filled with plastic bags, cans from various drinks. This debris was not digested and passed out naturally, which caused death. Chemicals dumped into the oceans kill as many dolphins in the sea every year as they do not eat in Sri Lanka even in 5 years. In the Red Book, the gray dolphin is listed as a protected animal and has the status of "vulnerable".