The Nile crocodile reaches a length of 6 meters. How much does a crocodile weigh? The smallest and largest crocodile

The life of a crocodile can hardly be called measured. During dry periods these toothy reptiles lie for a long time in the last remaining puddles, slowly using up wisely stored reserves of fat. It's a pitiful sight. But when a holiday comes to their street, crocodiles have few equals in their ability to instantly grab, drown or simply break the victim’s neck. Not being able to chew prey with its powerful but rather primitive jaws, the crocodile tears it into pieces in advance and sends it into the stomach in huge pieces.

The total mass of prey can be up to a fifth of the animal’s own weight.

Of course, these reptiles are far from their relatives, pythons, but it’s hard to imagine a person capable of peeling 15-20 kilograms in one sitting raw meat, and even with bones, it’s quite difficult.

According to American biologists, the crocodile can thank its unique system blood circulation Job by scientists at the University of Utah and the Artificial Heart Institute in Salt Lake City has been accepted for publication in the March issue of the journal Physiological and Biochemical Zoology.

In the body of most vertebrates - including crocodiles - blood moves through the so-called two circles of circulation. In the small, or pulmonary, it, passing through the lungs, is enriched with oxygen and gets rid of carbon dioxide; in the large, or systemic, it supplies oxygen to all organs of the body. Actually, neither one nor the other are full circles, since they are closed on each other: from the lungs the blood returns to the beginning great circle, and from organs - small.

In the body of mammals and birds, these circles, however, are clearly separated. In a small circle saturated carbon dioxide Blood arriving in the right atrium is driven into the lungs by the right ventricle. The left ventricle sends oxygen-rich blood coming from the left atrium further throughout the body. In fact, a four-chamber heart is two pumps in one, and this division even allows you to maintain significantly lower pressure in the small circle than in the large circle.

Amphibians and reptiles have a three-chambered heart - its atrium is divided in two, but there is only one ventricle, which sends blood further - both to the lungs and to the organs. It is clear that in this case partial mixing of the blood is possible, which makes the system not very effective. However, cold-blooded lizards and amphibians, for the most part leading not too active image life, can afford it.

The crocodile heart is a special case.

It has four chambers, but the circles of circulation are not completely separated. In addition, not only the pulmonary artery departs from the right ventricle, but also an additional, so-called left artery, most of blood through which is directed to the digestive system, primarily to the stomach. Between the left and right arteries (the right one comes from the left ventricle) there is a foramen of Panizza, which allows venous blood get to the beginning of the systemic circulation - and vice versa.

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Structure of the crocodile heart (RV - right ventricle, LV - left ventricle, FP - foramen of Panizza, RA - right aorta, LA - left aorta, PA - pulmonary aorta)
// pharyngula.org/Gazeta.Ru

In humans, this is an anomaly and is called congenital heart disease. The crocodile not only does not feel the defect here, but also has an additional mechanism that allows it to artificially pump oxygen-poor blood into the right artery. Or completely close the left artery, while its circulatory system will work almost the same as in mammals. The crocodile can control this so-called toothed valve at will.

The reasons that prompted nature to create such a remarkable mechanism have long occupied scientists. For a long time it was believed that the crocodile heart was a transitional stage on the way to the full-fledged four-chambered heart of warm-blooded mammals.

However, there was an opposite point of view, according to which the crocodile is a descendant of a warm-blooded animal, which, for evolutionary reasons, became more profitable to live the life of a cold-blooded killer. In this case, the Panizza foramen and the serrated valve turn out to be an adaptation mechanism that allowed the transition to a cold-blooded existence. For example, in 2004, Roger Seymour from the Australian University of Adelaide and his colleagues showed that such a heart structure can be very useful for a semi-underwater lifestyle: a decrease in oxygen in the blood can slow down the metabolism, which helps in long dives when a predator is motionless waiting for its kill. sacrifice.

Utah State University professor Colleen Farmer and her colleagues consider, that thanks to such a complex system, a crocodile can quickly decompose pieces of prey it has swallowed.

But a crocodile cannot hesitate: if a fish, a monkey, or even a human leg is not digested too quickly, the reptile will die. Either in the mouth of another predator due to its clumsiness, or from hunger and intestinal upset: in a hot climate, bacteria multiply very quickly on a swallowed piece of meat in the belly of an animal.

Farmer believes that the point is not that the blood that has not passed through the lungs is poor in oxygen - to achieve such an effect it is not necessary complex device heart, but just slow down your breathing. In her opinion, the fact is that this blood is rich in carbon dioxide. When a crocodile sends blood rich in CO 2 to the stomach and other digestive organs, special glands use it to produce gastric juice, and the more carbon dioxide they receive, the more active the secretion. It is known that in the intensity of secretion of gastric juice by their glands, crocodiles are ten times higher than the champions in this indicator among mammals. This allows not only to digest food, but also to suppress growth harmful bacteria in the stomach.

To prove their hypothesis, scientists first studied the condition circulatory system during periods of forced fasting and during the digestion of food by the crocodile. It turned out that in a crocodile that had just eaten, for many hours the valve actually causes the blood to flow predominantly bypassing the lungs.

Next, the scientists surgically deactivated the valve, closing the entrance to the left aorta, in a group of young crocodiles. For the purity of the experiment, the control group was also operated on, but their aorta was not closed. As it turned out, after feeding in crocodiles whose left aorta was blocked, the production of gastric juice was significantly reduced - despite the fact that blood continued to flow to the digestive organs in sufficient quantities through the right aorta. At the same time, the ability of crocodiles to decompose bones, which make up a significant part of their diet, also sharply decreased.

In addition to the function of carrying CO 2 to the stomach, Farmer notes, the circulation of blood bypassing the lungs could play another important function, the presence of which many gym-goers would envy.

For a crocodile, a rich meal almost always follows a dash for prey, during which the usually clumsy animal instantly jumps out of the water, grabs the prey that is gaping at the watering hole and drags it under the water. At this time, such an amount of toxic lactic acid is generated in the muscles (it is because of them that after physical activity muscle aches), which can cause the death of the animal. According to scientists from Utah, this acid is also transported through the blood to the stomach, where it is utilized.

As for Panizza’s foramen, its role is not only to direct oxygen-poor blood to other organs, slowing down the crocodile’s metabolism, but also, on the contrary, to supply digestive system supplemental oxygen from the right aorta when needed. The toothed valve helps from time to time send blood rich in carbon dioxide not only to the stomach, but also to other internal organs that may need it.

The Nile crocodile is a large reptile that belongs to the family of true crocodiles, living in Africa and being an integral link in aquatic and semi-aquatic ecosystems there. It is larger than most other crocodiles and is the second largest member of this family after the saltwater crocodile.

Appearance

The Nile crocodile has a squat body of a highly elongated format, which turns into a thick and strong tail, tapering towards the end. Moreover, the length of the tail can even exceed the size of the body. The strongly shortened powerful legs of this reptile are spaced widely - along the sides of the body. The head, when viewed from above, has the shape of a cone slightly tapering towards the end of the muzzle, the mouth is large, equipped with many sharp teeth, total of which there can be 68 pieces.

This is interesting! In crocodile cubs that have just hatched from eggs, you can notice a skin thickening on the front of the muzzle that looks like a tooth. This seal, called an “egg tooth,” helps hatchling reptiles break through the shell and quickly emerge from their eggs.

The color of Nile crocodiles depends on their age: young individuals are darker - olive-brown with a cross-shaped black shading on the body and tail, while their belly is yellowish. With age, the skin of reptiles seems to fade and the color becomes paler - grayish-green with darker, but not too contrasting stripes on the body and tail.

The crocodile's skin is rough, lined with rows of vertical scutes. Unlike most other reptiles, the Nile crocodile does not shed, since its skin tends to stretch and grow along with the animal itself.

Lifestyle

The Nile crocodile cannot be called a herd animal, but they live in large groups and often hunt in groups. At the same time, a strict hierarchy is observed in each group, which does not lead to conflicts. The largest individuals always dominate in groups.

But group hunting does not take place so often; more often individuals lead a solitary lifestyle. At dawn, the Nile crocodile comes out onto the coastal sand and dries in the sun, while its mouth is usually open at this moment. Having warmed up in the sun, the crocodile returns to the pond to hunt around noon. Since the Nile crocodile can eat quite a lot, it hunts almost every day, but in those cases when it is not hungry, at lunchtime it can either simply swim around the perimeter of its site, or remain in the coastal zone, half asleep. It is impossible to say that a crocodile ever completely falls asleep, since thanks to its sense of touch, it always feels everything that happens around it.

When a group of crocodiles is resting on the same beach, the dominant (i.e. larger) individuals are always in the most convenient places, and the distance between each crocodile is quite respectful. At sunset, the Nile crocodile always returns to the pond for hunting, which continues throughout the night and early morning. Thus, individuals of the Nile crocodile are predominantly nocturnal.

Nile crocodiles most often hunt for fish, but often swamp and water birds, small and large mammals that come to the pond where the crocodile lives to drink become prey. The Nile crocodile waits for its prey, completely immersed in the water and leaving only the eyes, nose and ears on the surface. It is capable of completely silently and imperceptibly swimming up to its prey at a sufficient distance, and then, in a sharp jump, grab the prey by the throat and also quickly drag it under water.

Underwater, a crocodile either strangles its prey or waits for it to choke. There have been cases when crocodiles left their prey under water for some time, placing it between the roots of trees, or in crevices so that the meat softened.

If the prey managed to avoid the attack of the crocodile, then it will not pursue it on land. It was extremely rare for crocodiles to rise more than halfway out of the reservoir while feeding. Crocodiles will also not hunt on the shore. Crocodiles can eat prey that is already dead, but they avoid meat in which the process of rotting has already begun.

The crocodile most often kills the fish with blows of its tail, after which it swallows it. When hunting in groups, several crocodiles herd fish into schools, where they have the opportunity to stun more prey. In this case, the larger individuals swallow the prey first, and their small relatives can only collect the remains of the dominant individuals.

Acoustic communication between individuals consists of a fairly extensive set of sound signals. Sounds always accompany mating tournaments. In addition, a characteristic dull moo can be heard when an individual is restless. An angry crocodile makes sounds similar to hissing sniffles. Young, newly hatched individuals make loud croaking sounds.

In general, the behavior of the Nile crocodile can be characterized as individual and social. He can manifest himself both in groups and alone. There is even a certain semblance of intelligence in it, and therefore cunning moves during the hunt are possible, as well as the ability to guard and protect the offspring, which is not typical of most other reptiles.

The Nile crocodile has the reputation of a cannibal, because due to carelessness, according to information from various sources, several hundred people become victims of crocodiles every year in their habitats. However official statistics no and confirm or deny this information impossible.

Habitat of the Nile crocodile

The Nile crocodile lives throughout almost the entire African continent.

In ancient times Nile crocodile found in Israel, Palestine, Lebanon, Algeria, Libya, Jordan, Syria and the Comoros Islands.

Now its habitat has shrunk slightly. Most individuals of the Nile crocodile live in Zambia, Ethiopia, Kenya and Somalia in the Nile basin. A smaller number of individuals live in Zanzibar, Morocco, Tanzania, Congo, Senegal, Sierra Leone, Uganda, Rwanda, Kenya, Liberia, Mozambique, Mauritania, Nigeria, Namibia, Malawi, Zaire, Botswana, Cameroon, Angola, Central African Republic, Chad , Burundi, Guinea, Cote d'Ivoire, Swaziland. The Nile crocodile is also found on nearby islands along the coasts of Africa: Madagascar, Socrates Island, Cape Verde Islands, the Sao Tome and Principe archipelago.

Nutrition

The daily menu of a crocodile, like most amphibians, is quite varied. Kids love to eat insects. As they get older, they prefer fish, shellfish and crustaceans. Adults find other prey - reptiles, birds. Sometimes their prey can be a large buffalo, rhinoceros, lion or tiger. Hiding in the water near the shore, they patiently wait for several hours until the animal approaches the shore. Having seen the prey, the predator quietly approaches it, while it unsuspectingly drinks water, it is not visible, because above the water only the eyes and nostrils of the crocodile. Suddenly, jumping out of the water, the crocodile grabs the victim by the head with its strong teeth and plunges it under the water. A choking animal becomes easy prey, and the crocodile enjoys it, tearing the victim into pieces with its powerful jaws, therefore, its attack is always a win-win.

An easy prey could be a frivolous monkey jumping from branch to branch, or a bird gaping on the shore or resting on large algae leaves.

Fish, Nile crocodile jams with a strong blow tail along the water surface and immediately easily swallows. They eat often, but due to their slow metabolism, they can go without food for several weeks, and even more than one month.

Surprisingly, crocodiles share prey with their brothers, of course, if they took part in the hunt. Having honestly divided the prey into pieces, the alligators calm down and rest, gaining strength before a new hunt.

Reproduction

During the mating season, males become especially aggressive. To attract friends, they snort loudly, roar and slap their muzzles on the surface of the water. Females choose a mate for themselves, swimming to the site of the male they like.

The newly-made spouses joyfully sing unique trills together and prepare for procreation. Having chosen a dry place, the female digs a hole in sand or soft earth up to 30-45 cm deep. She lays about 50 eggs in it and carefully buries them. During the entire incubation period (85-90 days), she stays close to the clutch, protecting it from uninvited guests. Often, her nearby spouse helps her in protecting her future offspring.

The crocodiles, ready to hatch, squeak pitifully, calling for help from their mother. She carefully digs up the sand and, holding the cubs in her mouth, carefully carries them to the pond.

Newborns weigh about 500 g with a body length of 25-30 cm. They spend the first weeks of their life in shallow water under the close attention of their mother, feeding on insects. At the age of 8 weeks, they split into small groups and look for shelter in the form of burrows, in which they live up to 4-5 years.

By this age, they grow up to 2 m and, no longer fearing enemies, go in search of their own territory. They reach sexual maturity at 12-15 years.

Nile crocodiles and humans

They have few enemies; the greatest danger to crocodiles is humans. They hunt them because crocodiles are quite dangerous predators, and besides, their skin became Lately a very valuable product.

As a result of barbaric destruction, there were almost none left on the shores of the reservoirs of the Middle East. Tropical reservoirs were under threat of existence, because their orderlies - crocodiles - were no longer there. They ate sick and weakened animals that came to the water to drink and lived in it, their remains, trash fish etc.

Soon, active work began in this direction. The situation is now under control and formidable predators bred on farms specializing in crocodile breeding. In addition, other measures are being taken to restore the number of animals.

• The ancient Egyptians worshiped the god of water and the flood of the Nile - Sebek, who was depicted as a living or mummified crocodile or a man with the head of a crocodile. The cult of the Nile crocodile was widespread among the Egyptians: predators were kept as pets, some individuals were decorated with jewelry during life, and after death they were mummified and buried with honors in a sarcophagus.
• An amazing fact: hippopotamuses and Nile crocodiles peacefully coexist in the same body of water, and female hippos can leave offspring next to the reptiles for protection from land-based predators.
• According to the observations of the researchers, interesting hypothesis, suggesting a symbiosis of Nile crocodiles with certain types birds - the spur lapwing and the Egyptian runner, which is also called the crocodile watchman. The Nile crocodile opens its mouth wide, and the birds pick out the remains of meat and leeches from its teeth. But it has not yet been possible to document the truth of such a symbiosis.
• The peak of extermination of Nile crocodiles occurred in the middle of the 20th century, when large aquatic reptiles were killed not only for their high quality skin, but also for edible meat and internal organs that supposedly have healing properties. Then the population of the species was on the verge of extinction. Currently, the Nile crocodile is listed in the Red Book of the World Conservation Union (IUCN).

Crocodylus niloticus) - a large reptile animal from the order of crocodiles, the family of crocodilians, the genus of the true.

The Nile crocodile is the most common member of the family, the largest African crocodile and the second largest giant reptile in the world, second only in size to the saltwater crocodile.

The main food of an adult Nile crocodile is various small and large mammals: cane rats, otters, bush cats, civets, . They become big prey different kinds(waterbucks, impalas, kudu, gazelles), large forest aardvarks, aardvarks, African manatees, as well as all types of domestic animals that accidentally wandered into a watering hole. The largest Nile crocodiles attack buffaloes, cubs and, brown hyenas and big cats.

Nile crocodiles also eat carrion, steal food from hyena dogs, etc. The predatory reptile has a slow metabolism, so the animal can for a long time starve, but with a successful hunt, the volume of food consumed at a time can be up to 20% of its own weight, and crocodiles feed at every opportunity. Only female Nile crocodiles, guarding their nests, eat little.

Reproduction of Nile crocodiles

Sexual maturity of Nile crocodiles occurs at 12-15 years of age, when males grow to 2.5-3 m, and females up to 2-2.5 m in length. Offensive mating season depends on the habitat: the northern part of the population breeds in the summer, and individuals living in the south breed during the rainy season - in November and December.

During the rut, special, hierarchical relationships are established among sexually mature males of the Nile crocodile. Quite aggressive clashes often occur between representatives of the species, in which males demonstrate their superiority over their opponent. Crocodiles exhale noisily through their mouths, make growling or grumbling-like sounds, and blow bubbles with their open mouths. Simultaneously with these demonstration actions, Nile crocodiles, excited by the fight for the future female, bend their necks, raise their tails, whipping them on the surface of the water. Having admitted defeat, one of the males turns around and high speed swims away, trying to escape the pursuit of a competitor. If it is not possible to escape, the losing crocodile raises its head high, opening access to its throat: this position is a sign of peace and recognition of defeat. The winning crocodile sometimes grabs one of the opponent's limbs with its jaws, but does not bite it. Such “prenuptial” fights make it possible to expel extra males from the territory favored by a pair of crocodiles.

During the breeding season, males behave quite unusually and interestingly: they roar invitingly, snort loudly, slap their muzzles in the water and try in every possible way to attract females, with females preferring the largest males. Mating games consist of singing peculiar trills, during which the partners open their mouths wide and rub the lower surfaces of their muzzles.

Sandy beaches and shallows, dry riverbeds and river banks become places for laying eggs. Near the water's edge, the female Nile crocodile digs a nest up to 60 cm deep and lays 20 to 95 eggs (usually around 55-60). The female vigilantly guards the buried clutch throughout the entire incubation period, which is approximately 90 days. Periodically, the male helps her, and the couple fights back against anyone who poses a threat to the offspring. Occasionally, the female is forced to hide from the heat, and the Nile crocodile's nest left unattended is destroyed by mongooses, spotted hyenas, baboons and people. Sometimes nests built in the wrong place suffer from floods. In total, only 10-15% of eggs survive to the end of incubation.

Taken from www.africawildtrails.com

Newborn crocodiles make grunting sounds, which becomes a signal for the female: she digs up the nest, and sometimes parents even help the cubs to be born by rolling the egg between the tongue and the palate.

The mother accompanies the hatched offspring to the pond or carries it in her mouth.

The sex of Nile crocodile cubs, like any other crocodiles, is formed under the influence of the temperature inside the nest during the second month of incubation: at temperatures from 31.7 to 34.5 degrees, males are born, in other cases females.

The length of newborn Nile crocodiles is approximately 28 cm, but in the first year of life the cubs develop quite quickly. By the end of the first year, crocodiles grow up to 60 cm in length, by two years - up to 90 cm. For two years, the female takes care of her offspring, sometimes together with other females, establishing something like a “nursery”, after which the grown individuals are about 1 .2 m leave their mother and, until puberty, avoid meeting with major representatives kind.

Young crocodiles dig holes up to 3.6 meters long in the banks, which serve as shelter for them until they are 5 years old. Adults also dig similar burrows for themselves under the roots of trees hanging over the water.

The most ancient animal, living since the time of dinosaurs, is the crocodile. And most dangerous species The Nile and saltwater crocodile are considered. It is on account of these animals greatest number human casualties.

In this article we will talk about the Nile crocodile.

It is found throughout the Seychelles and Comoros Islands, Madagascar. Relatively recently, it could still be found in Asia, but today it is completely exterminated there. Nile crocodiles divided into a large number of types:

These are found in rivers and freshwater. They can reach a length of 4 to 6 meters, but giants with a length of 7 meters are also known. These animals can weigh from 270 to 910 kg.

From the photographs it can be seen that Nile crocodiles do not have a very long muzzle, which does not exceed its width. Young animals are brown and also dark olive in color. An adult crocodile is dark green in color with black spots on its back, and its belly is lighter than the rest of the animal's body, often a dirty yellow color. With age, the reptile becomes more and more pale.

The nostrils and eyes of crocodiles are located at the top of the head, which is why they can breathe and see when the rest of the body is in the water. Unlike other animals, these reptiles have external ears that close like the nostrils when crocodiles dive.

The Nile crocodile is a diurnal animal. During the night they lie down in bodies of water, and when the sun rises, they go hunting, or continue to rest in the sun.

Nutrition and hunting of the Nile crocodile

The Nile crocodile eats quite varied. Small reptiles feed on, for example, dragonflies. Larger crocodiles eat molluscs, fish, and crustaceans. Sometimes their prey is a bird, a reptile, or a mammal such as a rhinoceros or buffalo. Sometimes animals attack lions and tigers.

The reptile waits for its future victim in the water, near the shore. It may take more than one hour until something living approaches the water. Then the reptile swims closer to the prey and waits at a distance of about several meters, at which time its body is immersed in water, with the exception of its eyes and nostrils. Suddenly, the reptile jumps out of the water and grabs the victim's head with its mouth, drowning it, dragging it into deep water. Then, with the help of its powerful jaws, the crocodile tears out parts of the meat.

When hunting fish, the reptile hits its tail to stun and frighten it, and the one that is stunned is swallowed. Reptiles feed quite often, although they can go without food for several days, sometimes a year or even more.

Crocodiles are remarkably adapted to living underwater and in the water. They use their paddle-like, powerful tail to swim. The hind legs are webbed. Another adaptation to aquatic life is the presence of a third eyelid: a membrane that, when immersed under water, protects its eyes, while the crocodile can see further. Crocodiles can stay under water for a very long time: on average, about forty minutes, and older crocodiles may not surface for more than one hour.

Of course, on land reptiles are slower than in water, but they still develop a fairly good speed of 30 km/h. But the most interesting thing is that on land crocodiles are very cowardly and do everything possible to run away to the water as quickly as possible. It is for this reason that only about 3 out of 10 reptile attacks occur on land.

Reproduction of Nile crocodiles

Crocodiles become ready to reproduce only at 8-12 years of age. A female individual lays 50 eggs. Throughout the entire incubation period, a period of 80-90 days, she remains close to the nest, then provides assistance to the newborns in getting out of the nest. Young crocodiles live with their mother for two years.

Crocodile animal reptile, part of the order of aquatic vertebrates. These animals appeared on Earth more than 200 million years ago.

The first individuals first lived on land and only later mastered aquatic environment. The closest relatives of crocodiles are considered.

Features and habitat of the crocodile

Life in water has formed the corresponding body of a reptile: the body of crocodiles is long, almost flat, with a flat long head, a powerful tail, short paws with toes connected by membranes.

Crocodile is a cold-blooded animal, his body temperature is about 30 degrees, sometimes it can reach 34 degrees, it depends on the temperature environment. Animal world crocodiles very diverse, but species differ only in body length; there are reptiles up to 6 meters, but most are 2-4 m.

The largest saltwater crocodiles weigh more than a ton and have a length of up to 6.5 m, they are found in the Philippines. The smallest land crocodiles, 1.5-2 m, live in Africa. Under water, the crocodile's ears and nostrils close with valves, transparent eyelids fall over the eyes, thanks to them the animal sees well even in muddy water.

The mouth of crocodiles does not have lips, so it does not close tightly. To prevent water from entering the stomach, the entrance to the esophagus is blocked by the velum palatine. The crocodile's eyes are located high on the head, so only the eyes and nostrils are visible above the surface of the water. The brown-green color of the crocodile camouflages it well in the water.

The green tint predominates if the ambient temperature is elevated. The animal's skin consists of durable horny plates that protect well internal organs.

Crocodiles, unlike other reptiles, do not shed; their skin constantly grows and renews itself. Thanks to its elongated body, the animal maneuvers well and moves quickly in the water, while using its powerful tail as a rudder.

Crocodiles live in fresh waters of the tropics. Eat species of crocodiles, well adapted to salt water, they are found in the coastal strip of the seas - these are combed, Nile, African narrow-snouted crocodiles.

Character and lifestyle of a crocodile

Crocodiles are almost constantly in the water. They crawl ashore in the morning and evening to warm their horny plates in the sun. When the sun is hot, the animal opens its mouth wide, thus cooling the body.

Birds, attracted by leftover food, can freely enter the mouth at this time to eat. And although crocodile predator, wild animal he never tries to grab them.

Crocodiles mainly live in fresh waters, in hot weather, when the reservoir dries out, they can dig a hole at the bottom of the remaining puddle and hibernate. During drought, reptiles can crawl into caves in search of water. If hungry, crocodiles are able to eat their relatives.

On land, animals are very clumsy and clumsy, but in water they move easily and gracefully. If necessary, they can move to other bodies of water by land, covering several kilometers.

Nutrition

Crocodiles hunt mainly at night, but if prey is available during the day, the animal will not refuse to feast on it. Receptors located on the jaws help reptiles detect potential prey even at a very long distance.

The main food of crocodiles is fish, as well as small animals. The choice of food depends on the size and age of the crocodile: young individuals prefer invertebrates, fish, amphibians, adults prefer small mammals, reptiles and birds.

Very large crocodiles can easily handle victims larger than themselves. This is how Nile crocodiles hunt during their migration; the saltwater crocodile hunts livestock during the rains; Madagascar can even eat.

Reptiles do not chew food; they tear it into pieces with their teeth and swallow them whole. They can leave prey that is too large at the bottom to soak. Stones swallowed by animals help in digesting food; they crush it in the stomach. Stones can be of impressive size: a Nile crocodile can swallow a stone up to 5 kg.

Crocodiles do not eat carrion unless they are very weak and unable to hunt; they do not touch rotten food at all. Reptiles eat quite a lot: they can consume about a quarter of their weight in food at a time. About 60% of the food consumed turns into fat, so the crocodile can fast for up to one year if necessary.

Reproduction and lifespan

The crocodile is one of the long-lived animals, he lives from 55 to 115 years. Puberty occurs early, at approximately the age of 7 - 11 years. Crocodiles are polygamous animals: a male has 10 - 12 females in his harem.

Although the animals live in water, they lay eggs on land. At night, the female digs a hole in the sand and lays about 50 eggs there, covering them with leaves or sand. The size of the depression depends on the illumination of the place: in the sun the hole becomes deeper, in the shade it is not very deep.

The eggs mature for about three months, during which time the female remains close to the clutch, practically not feeding. The sex of future crocodiles depends on the environmental temperature: females appear at 28-30° C, males at temperatures above 32° C.

Before they are born, the babies inside the eggs begin to grunt. The mother, hearing the sounds, begins to dig out the masonry. Then he helps the babies free themselves from the shell by rolling the eggs in their mouths.

The female carefully transfers the emerging crocodiles, measuring 26-28 cm, into a shallow body of water, capturing them in her mouth. There they grow for two months, after which they disperse to the surrounding, not heavily populated, reservoirs. Many small reptiles die, they become victims of birds, monitor lizards and other predators.

Surviving crocodiles first feed on insects, then hunt small fish and, from 8-10 years of age, begin to catch larger animals.

Not everyone is a danger to humans species of crocodiles. So the Nile crocodile and the saltwater crocodile are cannibals, but the gharial is not at all dangerous. Crocodile as a pet Today they are even kept in city apartments.

In their habitats, crocodiles are hunted, their meat is eaten, and their skin is used to create haberdashery, which has led to a decline in the crocodile population. In some countries today they are bred on farms; in many tribes they are considered the crocodile is a sacred animal.