Grinds are a species of dolphins, quite large. Scientists say that in behavior these animals are more like whales than other dolphins.
The scientific name - spherical-headed - was obtained by the dolphin thanks to a large head with a sloping forehead.
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There are two subspecies: common grind and short-finned.
Sexual dimorphism in them is weakly expressed. One can distinguish a male from a female only in size. The males are larger than their relatives - the adult dolphin can reach 6 m in length, and females rarely grow more than 4.8 m. The weight of adult animals can range from 800 kg to 3 tons.
Sideways fins are located along the body of the grind. They are very well developed and, as a percentage of size, are larger than other dolphins. The dorsal fin is medium in size and resembles a crescent in shape. Despite the name, the head of a bald-headed dolphin is more like a melon: it has a streamlined shape, tapers to the muzzle and in the back of the head.
Grind skin is gray, there may be spots on it (below the dorsal fin, on the belly, around the eyes).
The body shape has excellent streamlining, which contributes to good speeds in the aquatic environment. Dolphin can easily accelerate to 40 km / h.
From the photo of the grind dolphins, we can conclude that these animals are quite strong. It really is. The Grinds are excellent swimmers and agile hunters.
Habitat
Ordinary grinds are rather large predators who prefer a cool climate. Populations settle closer to the poles of the planet.
The Atlantic population is quite large. Researchers have repeatedly found dolphins not only within the framework of their usual geography (off the coast of Scandinavia, Great Britain, Greenland), but even in the Mediterranean Sea. True, the grinds feel insecure in the unusually warm water and are not located for a long time off the coast of Tunisia and Algeria. It is believed that ordinary curiosity drives them to such risky swims.
The southern population lives in the cool waters near the Orkney and Sandwich Islands, to the south of the dolphin flock they try not to swim. Grind is a frequent guest in the coastal waters of Africa and off the southern coast of Australia, as well as along the Pacific coast of South America, from where it often swims to Peru.
As for the short-fin variety, it lives in the middle latitudes of the entire oceans.
These animals are smart, they are characterized by curiosity and a craving for research.
Habitat behavior
Grind dolphins are animals that prefer to live collectively. They have a strong instinct for protecting the flock, they come to the rescue of relatives. If one individual enters the network or some kind of trouble happens with it, the rest immediately rush to the rescue.
Oddly enough, but at the head of the pack is not a male, but an old experienced female. The remaining members of the group obey her. Usually in a flock there are about fifty individuals or a little more.
Food
Grinda's diet is based on cephalopods. But the balloon-headed dolphins do not really like fish, they eat it only if the main food is not enough. Unlike other brethren, grinds are more often engaged in gathering than chasing: they catch mollusks at a depth of 30 to 60 meters. But, if necessary, they can also dive to great depths - up to 600 meters. True, like all dolphins, they cannot spend more than a quarter of an hour under water.
Breeding and raising offspring
Grind grow up slowly. The maturity of males occurs at 12 years old. Females can perform a childbearing function earlier - from 7 years.
Body growth lasts up to 20 years.
The life expectancy of males is relatively small: they rarely live up to 45 years. Females live longer - up to 60 years, and fertility in some remains almost until the end of life. It is noteworthy that the grind is one of the three species of mammals whose females pass through the menopause (the other two species are killer whales and humans).
Pregnancy lasts about 15 months. Newborn grindas are rather large strongies, their average birth weight slightly exceeds 100 kg, and their body length can reach 1.8 meters. It is believed that females always give birth to one cub each, since scientists have no reliable information on cases of multiple pregnancies.
The mother feeds the dolphin with milk up to 2 years old, while simultaneously teaching the wisdom of spearfishing.
