African Сrocodile

 Order Crocodilia - a family of reptiles. In Africa, three lived. Uzkoryly Crocodile - endemic to Africa. It lives in all the major rivers of West Africa, Lake Tanganyika and the eastern mainland. Tuporyly (or pygmy) crocodile - in central Africa. Nile crocodile - on the mainland and some islands.
 Crocodiles have a special position among modern reptiles, being more closely related extinct dinosaurs that survived the nearly 60 million years, and modern birds than other reptiles of our time. Several features of the organization of crocodiles, and especially the perfection of the nervous, circulatory and respiratory systems, makes them the most highly organized of all living reptiles. Evolution of the crocodiles, since the advent of this group of about 150 million years ago, went in the direction of increasing adaptation to aquatic life, and predation. The fact that crocodiles have survived to our time, is often explained by their life in a variety of freshwater tropical and subtropical zones, ie in places where conditions have changed little since the appearance of crocodiles.
 The general form of the body, crocodile yascheritseobraznaya. They are characterized by long, laterally compressed, high tail, webbed toes of the hind limbs, a long snout and flattened in a dorsoventrally head. The front legs of the five fingers on the back - four (no pinky). The nostrils are located on the front end of the muzzle and eyes raised and placed on the upper side of the head that allows you to keep crocodiles in the water with its surface exposed to air only the eyes and nostrils. External auditory aperture closed movable flaps that protect the eardrum from mechanical damage when immersed in water. The body, tail and legs are covered with large crocodiles regularly shaped horny plates, placed on the back and abdomen straight rows.
In the inner layer of the skin (corium), under the outer layer of horny plates on the back and in some species in the belly of developing bone plate (osteodermy) is firmly connected with the horny scutes, forming a shell, which protects the body of a crocodile is well on his head osteodermy fused with the bones of the skull.
 Modern crocodiles inhabit different fresh water. Relatively few species tolerant of brackish water and are found in river estuaries (African uzkoryly crocodile, Nile crocodile, American crocodile ostroryly). Only grebnisty crocodile swims far out to sea, and was celebrated at a distance of 600 km from the nearest land. Most of the crocodiles spend hours in the water. In the coastal shallows out in the morning and late afternoon - warm in the sun.
 Hunt alligators at night. A compulsory component of the diet of crocodiles is fish, but the crocodiles devoured any prey, which can cope with. Therefore, a set of feed varies with age: the young are the food of various invertebrates - insects, crustaceans, mollusks, worms, larger animals prey on fish, amphibians, reptiles and water birds. Adult crocodiles are able to cope with large mammals. Well-known case of being in the stomach remains of a rhinoceros Nile crocodile. In many species of crocodiles observed cannibalism - devouring the larger individuals of smaller ones. Most crocodiles feed on carrion, and some kinds of hidden nesedennye remains of the victims under the overhanging bank, and later devour their semi-decomposed. Crocodiles move in water by the tail. On land, crocodiles are slow and clumsy, but take some significant transitions, a few kilometers away from the water. With the rapid movement of crocodiles put legs under the body (usually they are far apart), which rises high above the ground. Young Nile crocodiles can run at a gallop at a speed of about 12 miles per hour. Crocodiles lay eggs the size of a goose or chicken, covered with calcareous shell. The number of eggs per clutch in different species varies from 10 to 100. Some species bury their eggs in the sand, while others lay in a nest made by the female of the rotting vegetation. The female remains near the masonry, protecting it from enemies. Young crocodiles are still inside the egg at the time of hatching emit croaking sounds, after which the mother digs out the clutch, helping to get their offspring.
 Crocodiles are growing rapidly in the first 2 - 3 years of life, during which the reach of crocodiles and gavials. the size of 1-1.5 m with age growth rate falls, and they add to the length of several centimeters per year. Reach sexual maturity at the age of 8-10 years. Crocodiles live to 80 - 100 years old. Enemies of adult crocodiles little, if we exclude the person. Cases of assault elephants and lions, crocodiles, making the transition to land from one pond to another.
 In Africa, the Nile crocodile is widely raspostranen (Crocodylus niloticus). It can be found throughout Africa, except for the northern part of Madagascar, Comoros and Seychelles. Most often settles out of the forest, but comes in forest ponds. Reaches a length of 4-6 m just hatched from eggs cubs have a length of about 28 cm by the end of the first year of life up to 60 cm to two years - 90 cm, in 5 years - 1.7 m in 10 years - 2 3 m in 20 years - 3.75 pm The night is carried out in water, and by sunrise out in the shallows and basking in the sun. Noon, the hottest hours spend in the water, except for cloudy days. In windy, rainy weather, spend the night on the beach. Limiting the length of stay under water for the animals of about 1 m in length is about 40 minutes, larger crocodiles can be under water for much longer. Food Nile crocodile is very diverse and varies with age. In calves up to 30 cm long 70% of food are insects. Larger individuals (approximately 2.5 m in length) feed on fish, mollusks, crustaceans, and even larger - fish, reptiles, birds and mammals. Adult Nile crocodiles may attack large mammals such as buffalo and even a rhinoceros. Beasts crocodiles lie in wait at the watering places, in water or on land in the grass. In some localities Nile crocodiles are dangerous to humans. Egg laying is always in the dry season when water level is low. Females dig a burrow in the sand up to 60 cm deep, which lay 25-95 (average 55 - 60) eggs. Incubation lasts about 90 days, during which the mother stays postoyant but the nest, guarding the eggs. Apparently, at this time the animal does not eat. By the time of hatching, the young crocodiles inside the eggs begin to publish the grunting sounds that serve to signal the mother that helps pups get out from under the sand, and accompanying them to the water. At this time the female may attack a person, even on land. Hatching from eggs usually occurs after the first rains fall, with the rise in water levels in lakes and rivers, so that the young crocodiles are just flowing waters in the shelter and food. After the release of the young crocodiles from eggs the mother takes them (as reported by the Cotta) to the selected its "child" - shallow body of water protected by vegetation. Here the young crocodiles are about six weeks, all the while the mother stays with the brood, protecting it from attacks by predators. In the absence of the mother hatched krokodilyata often remain near the nest, where they are generally destroying predators - herons, Goliath, marabou, kites. There are numerous cases of cannibalism (devouring the eggs and juveniles), which is usually considered the mechanism of regulation of the number of the form indicated that cannibalism is more frequent, the higher the number of crocodiles. The number of Nile crocodiles generally fallen and continues to fall. In ancient Egypt, crocodiles were revered as sacred animals, now they are almost exterminated. The same fate befall crocodiles in some areas of Central and East Africa, if not taken measures to protect species.