Anatomical structure of a crocodile. The special structure of the heart of a crocodile can help him in digestion Nile crocodile where he lives

The Nile crocodile (lat. Crocodylus niloticus) is one of three species of crocodiles that live on the African continent. It is smaller but more aggressive. It can live near human settlements and is famous for its cannibalistic inclinations, therefore in ancient Egypt it was revered as a sacred animal of the god Sebek, depicted with a human body and a crocodile head.

Sebek was considered the protector of gods and people, was the deity of reservoirs and the flood of the Nile. In the ancient Egyptian city of Shedit, located on the shores of Lake Merida in the Fayum oasis and better known by the Greek name Crocodilopol, the priests in the temple of Sebek kept a huge Nile crocodile adorned with jewelry made of gold and precious stones. Sometimes human sacrifices were made to him, because the gluttonous reptile was the living embodiment of Sebek with all the ensuing consequences.

Several burials of these reptiles have been discovered in Egypt. After death, they were mummified and decorated with jewels.

During life, they were intensively fed, cherished in every possible way and carried on special stretchers. The slaves delighted the ears of the reptiles with exquisite music. A respectful attitude towards them has been preserved by almost all the peoples of Africa to this day.

Spreading

Zoologists currently distinguish 7 subspecies of Crocodylus niloticus, living in different regions and having slight external differences. It is found throughout the sub-Saharan continent and Madagascar. Most often observed in slow-flowing rivers or stagnant reservoirs, prefers swampy areas.

Giant reptiles settle in mangrove forests, provided that there is a beach well warmed by the sun and dense reed beds where you can hide in ambush and hide from prying eyes.

Behavior

Nile crocodiles live in loose communities that usually include several groups. Each group consists of animals of the same sex and approximately the same age and size. The dominant role is always occupied by males.

Each male occupies his own area, including part of the coast and part of the water area adjacent to it. Females mostly stay together and even nest in the neighborhood.

Representatives of this species have a very rich language of communication, expressed through a variety of body movements and a rich set of sounds.

A reptile of a lower rank always hides its head in the water in front of a higher one in the hierarchy. The dominant male proudly swims with his body, head and tail above the water. The subordinate exposes only his muzzle.

On land, to scare off rivals, the Nile crocodile rises on all four legs, swells up and lifts its head and tail high. In the case of rare fights, the giants bite each other on the paws and the base of the tail. They lie in wait for their victims at the watering hole and at the crossings.

The toothy monster jumps out of the reservoir with a powerful jerk, grabs the victim by the muzzle or leg, pulls it down and drowns, and then slowly eats it. With sharp teeth, he tears off large pieces of flesh and swallows them without chewing.

Nile crocodiles collectively hunt schooling fish, driving them together in shallow water. They often grab waterfowl, and with their tail they manage to knock down their nests in order to feast on eggs.

After a meal, the predator lays down in the sun to better digest food, and when hungry, hides in the shade, saving energy.

An adult eats about 50 large meals during the year, but can go without food for up to 2 years, limiting energy consumption and using fat reserves, which are located in its tail, along the ridge and body cavities.

The largest specimen weighed more than 1 ton and was about 8 m long.

reproduction

During the mating season, males become especially aggressive. To attract girlfriends, they snort loudly, roar and slap their muzzle on the surface of the water. Females choose their own mate by swimming to the site of the male they like.

The newly-made spouses joyfully sing peculiar trills together and prepare for procreation. Having chosen a dry place, the female digs a hole in the sand or soft earth up to 30-45 cm deep. She lays about 50 eggs in it and carefully buries them. All the time of incubation (85-90 days), she keeps close to the masonry, protecting it from uninvited guests. Often in the protection of future offspring she is helped by a nearby spouse.

Ready to hatch, crocodiles squeak plaintively, calling for help from their mother. She carefully digs up the sand and, holding the cubs in her mouth, gently 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 lives in shallow water under the close attention of their mother, eating insects. At the age of 8 weeks, they break into small groups and look for shelters in the form of holes, 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 site. They reach sexual maturity at 12-15 years of age.

Description

Adult individuals reach a body length of 3.5-5 m with a weight of about 800 kg. The color is dominated by gray or dark olive color with characteristic dark transverse stripes.

Along the upper side of the tail, two longitudinal ridges stretch from the very base, which merge together in the middle.

The legs are short and very strong. The toes of the hind legs are connected by swimming membranes. All fingers are armed with powerful claws. The tail is long and massive, it serves as a kind of rudder and oar when swimming. The mouth is elongated. Both jaws are equipped with sharp strong teeth.

At the front end of the muzzle are the nostrils. Eyes with vertical pupils are set high on the skull.

The life expectancy of the Nile crocodile in the wild is about 100 years.

The Nile crocodile for many centuries inspires fear and horror in all living organisms that live next to it. Mention of this reptile dates back to the time of the existence of Ancient Egypt, and there are also hypotheses that crocodiles lived in the time of dinosaurs.

To date, the population of the Nile crocodile in the world has 250-500 thousand individuals and is included in the "Red List of Threatened Species" as a taxon of minimal risk (LC). In the 1940s - 1960s, the extermination of the Nile crocodiles for the sake of extracting their skin led to a sharp decrease in the population, and only thanks to the national and international measures taken, the extinction of the species was stopped. However, despite all efforts, cases of poaching are not uncommon. In addition, the lack of education and knowledge of proper behavior among the natives of the habitats of the species leads to the extermination of individuals that threaten the lives of careless people and domestic animals.

The Nile crocodile is one of the largest reptiles, which reaches a length of 5-6 meters along with the tail. However, depending on the habitat, certain features of the species are distinguished, including in size. The average weight of an adult is 600-800 kg with a length of 4-5 meters. Individuals whose length reaches 6 meters or more weigh about 1000 kg.

The body structure of the Nile crocodile allows the species to be perfectly adapted to hunting in the aquatic environment. The reptile's tail is long and powerful, which helps it swim quickly and, starting from the bottom of the reservoir, quickly jump out over distances that are much larger than the size of the reptile itself. The body of the Nile crocodile is flattened, the short hind legs are equipped with wide membranes, the jaws are long and powerful. The skin of the Nile crocodile, unlike most of its relatives, is rather smooth without ridges and covered with scales. There are 4-6 scutes on the back of the head, the dorsal scutes are separated from the occipital and placed in equal rows. The organs of vision, respiration and hearing are located on the top of the crocodile's head, which allows it to dive under water, hiding from prey, and at the same time observe the surroundings. Crocodylus niloticus has 64-68 teeth, 36-38 of which are maxillary, 28-30 are mandibular.

The color of young individuals is greenish with bright black spots on the sides, on the back and a straw-yellow hue on the belly and throat. With age, the color fades and becomes darker from olive to dark green on the sides, on the back, and the belly and throat acquire a dirty yellow tint.

In addition to all of the above, the skin of the Nile crocodile is equipped with highly sensitive receptors that respond to the slightest vibrations of water. The reptile sees perfectly not only during the day, but also at night. But at the same time, the hearing and sense of smell of the Nile crocodile are developed much better than vision.

The three-chambered heart well saturates the blood of the reptile with oxygen, which allows, if necessary, to be under water for up to two hours with reduced activity. Usually, the Nile crocodile draws enough air into the lungs to be on the surface of the water and releases it in order to quickly dive deep into the depths. A crocodile dives for an average of 2-3 minutes. When a crocodile dives underwater, its ears close, as do its nostrils. At the same time, the eyes are closed by a membrane (the so-called third eyelid), which protects them from exposure to water and at the same time allows you to see. In addition, for washing the mucous membrane, there are glands around the eyes of the crocodile, which were the basis of the aphorism "crocodile tears".

The Nile crocodile is able to open its mouth in the water thanks to a leathery growth, which is located at the back of the throat and blocks the access of water to the respiratory system.

The metabolism of Crocodylus niloticus, like that of most cold-blooded animals, is rather slow, which allows it to go without food for tens of days. But at the same time, a hungry crocodile is able to eat up to half its own weight at a time.

The dimorphism of the crocodile is expressed only by the primary sexual characteristics and the size of individuals - males usually exceed females in size. Therefore, it is not possible to determine the sex of a crocodile by external signs.

In the wild, Nile crocodiles can live up to 60-70 years.

Origin and habitats in nature

The species Crocodylus niloticus belongs to the genus Crocodylus (Real crocodiles) of the Crocodylidae family (Crocodiles). Informally, several subspecies are recognized, some of which have DNA analysis showing differences, suggesting possible genetic differences among populations. However, to date, this fact has not been fully studied, and it is possible to speak only about the existing differences in the size of individuals, which may be due to the habitat.

In countries with a cool climate, the size of an adult is on average 4 m (South African Nile crocodile), while in Mali and the Sahara desert, the size of adults does not reach more than 2-3 m in length, due to which they were called Dwarf Nile crocodiles.

The habitat of the species Crocodylus niloticus extends over almost the entire territory of Africa, in the Nile River basin, south of the Sahara, as well as in Morocco, Mauritius, Sao Tome and Principe, Cape Verde, Zanzibar, Socotra Island and Madagascar. Judging by the fossil remains, this species previously lived much further north - in Algeria, Libya, Lebanon, Syria, Palestine, Jordan, the Comoros and was most recently exterminated in Israel. In addition, a small population of the species also lives in Palestine today, but in a single place - the Crocodile River.

The habitat is limited to freshwater or slightly brackish lakes, rivers, swamps, and estuaries. It can be noted that the Nile crocodile prefers to live in more or less calm water, with a sandy coastal zone. It is extremely rare to find the Nile crocodile at a great distance from the reservoir. And this may be due to the search for a new habitat in connection with the drying up of the reservoir on the previous one.

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. Groups are always dominated by the largest individuals.
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 reservoir for hunting closer to noon. Since the Nile crocodile can eat quite a lot, it hunts almost every day, but in those cases when it is not hungry, then at lunchtime it can either simply swim along the perimeter of its site, or remain on the coastal zone half asleep. It is impossible to say that a crocodile ever completely immerses itself in sleep, because thanks to the organs of touch, it always feels everything that happens around.

When a group of crocodiles rests on the same beach, the dominant (i.e. larger) individuals are always in the most convenient places, while 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 hunt most often for fish, but often marsh and water birds, small and large mammals that come to the reservoir where the crocodile lives, to drink, become prey. The Nile crocodile waits for its prey, completely immersed in water and leaving only eyes, nose and ears on the surface. He is able to completely silently and imperceptibly swim up to his prey at a sufficient distance, so that in a sharp jump he grabs the prey by the throat and also quickly drags it under water.
Under water, a crocodile either strangles its prey or waits for it to choke. There have been cases when crocodiles left their prey under water for a while, 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. Extremely rarely, during feeding, crocodiles climbed more than half the exit from the reservoir. Crocodiles will also not hunt on the shore. Crocodiles can eat already dead prey, but they avoid meat in which the process of decay has already begun.

The crocodile most often suppresses the fish with the blows of the tail, after which it swallows it. When hunting in groups, several crocodiles drive fish into schools, where they have the opportunity to stun more prey. At the same time, larger individuals are the first to swallow prey, and their small relatives can only collect the remains after dominant individuals.

Acoustic communication between individuals consists of a rather extensive set of sound signals. Sounds always accompany mating tournaments. In addition, a characteristic dull lowing can be heard during the anxiety of the individual. An angry crocodile makes sounds like a hissing sniff. Young, newly hatched individuals make sonorous croaking sounds.

In general, the behavior of the Nile crocodile can be characterized as individual and social. It can manifest itself both in groups and singly. It even has some semblance of intelligence, and therefore cunning moves are possible during the hunt, as well as the ability to protect and protect offspring, which is not characteristic of most other reptiles.

The Nile crocodile has the glory of a cannibal, because, due to indiscretion, according to information from various sources, several hundred people become victims of crocodiles in their habitats per year. However, there are no official statistics and it is not possible to confirm or deny this information.

When deciding to keep the Nile crocodile in captivity, a person must understand the full measure of responsibility towards this animal and their loved ones who may be near it. In the presence of a crocodile, a person can never be careless, because, first of all, the Nile crocodile is a dangerous predator with great strength, lightning-fast reaction, as well as all the qualities inherent in it by nature, designed for successful hunting. The crocodile will never become tame, and therefore it must be treated with caution, not being deceived by its apparent indifference.

Terrarium: given the considerable size of the species Crocodylus niloticus, it is necessary to prepare a spacious terrarium. Even for a young individual, a fairly large space is needed, because they grow quite quickly, and a small terrarium can last no more than 1-2 years. Therefore, it is better to prepare a terrarium with the expectation of an adult immediately.

For the Nile crocodile, it is recommended to prepare a large pool where he can swim freely. The size of the pool should be at least twice the size of the reptile in length and at least the minimum headroom for a turn. In a ratio of 1:1 with a pond in the aquaterrarium, there should be an island of land, over which a warming point should be organized.

The water level in the pool must be at least half a meter. The water in the terrarium must be fresh and free of harmful impurities, such as chlorine. In addition, it is desirable to make the reservoir flowing and install a sufficient number of filters. Water should always be clean, it is recommended to resort to partial replacement 1-2 times a week. A complete replacement of the water in the pool must be done at least once a month.

Substrate: the most optimal type of substrate on land will be coarse gravel with sand, which, if necessary, can be washed and dried. It is necessary to place several large and medium stones and snags in the water. Landing should be comfortable and gentle.

Content temperature: The Nile crocodile is a heat-loving tropical animal, and therefore the temperature of keeping should be at least + 34 ° C during the day and not lower than + 24 ° C at night. The water temperature should be maintained at +28 - +30°C. A warm-up point must be organized in one corner of the terrarium so that the crocodile can control its own body temperature.

Lighting: During the day, the terrarium should be well lit. In addition, a prerequisite for the successful assimilation of minerals important for the body of a crocodile is the presence of an ultraviolet radiation lamp. It is necessary to monitor the daily rhythm and arrange lighting in such a way that twice a day there is a period of twilight.

Decor: to create partial shade in the terrarium, unpretentious tropical plants can be planted - they will also decorate the space, but for crocodiles, the presence of vegetation is not a prerequisite at all.

Feeding in captivity

Feeding Nile crocodiles in captivity should be as close as possible to their diet in the natural environment. So the menu of young animals can be large insects, frogs, newborn mice. Adults can be fed rats, live fish, unplucked chicken. It has been noted that after fish, crocodiles easily switch to eating meat, but if they are fed only meat for a rather long period, then they may refuse fish. But this phenomenon is temporary and, having been a little capricious, the pet will also eat fish.
Pre-killed prey, cuts of meat, or thawed fish are suitable for feeding captive-bred individuals who are trained to consume such food. But even in this case, the volume of live prey should prevail.

Adult feeding intervals can be 4-6 days, while juveniles need to be fed every other day. The amount of food for an adult to eat per week should be 5% of body weight, and for young animals - 10%.

Vitamin supplements in the form of calcium and other important elements that make up vitamin complexes for reptiles should be given once a week to young animals and once a month to adults.

Breeding

Under good conditions, individuals of the Nile crocodile become sexually mature by about 8-10 years, when their body size reaches 3 m for males and 2-2.5 m for females.

The mating season begins with male tournaments, which are observed by the female and give preference to the largest male. Roars, snorting, slamming their heads on the water - this is not a complete list of ways in which males try to attract the attention of a female during the mating season. During mating games, the resulting pairs rub the undersides of the muzzle and make various sounds.
The beginning of the mating season falls on the dry season. Mating takes place in the water and lasts 1-2 minutes. Approximately 60 days after mating, the female begins to dig a hole, about 50 cm deep on land, in the sand. Often in the wild, several females dig holes close to each other and jointly protect the masonry.

One clutch consists of 40-60 eggs. After laying eggs, the female fills the nest with rotting vegetation, which during the decay process creates additional heat, which contributes to better egg incubation, and also masks the nests from predators. Despite the fact that females, and sometimes males, very jealously guard the masonry, they are often devastated by other predators. But the most common cause of masonry death is early rains, which flood nests close to water bodies.

The incubation period is on average 80-90 days. The sex of the pups is determined by the incubation temperature. Young animals have a small growth (egg tooth) in the nose area, thanks to which they can peck the egg. Pecking the egg, small crocodiles begin to make ringing sounds, which are a signal for the female, after which she opens the nest and often, together with the male, helps the young to get out of the egg, widening the crack in it with their tongue, and then carry them to the water.

Pairs protect cubs up to 2 years, after which they drive them from their site. Then the young wander along the reservoirs one by one, trying not to catch the eye of adults who can feast on the young. Having reached puberty, young crocodiles return to their native shore.

When breeding Nile crocodiles in captivity, it is necessary to place a sufficient amount of vegetation in the terrarium, prepare a place with a substrate in the form of a mixture of moss, peat and shavings. The substrate must be sufficiently hygroscopic, since the embryos receive moisture not only from the air, but also from the soil.

In order for sexually mature individuals to pay attention to each other, it is recommended to keep the female separately until the mating season. If you plant a female with two sexually mature males, then skirmishes will begin, during which the animals can severely injure each other.
The incubation temperature should be +30 - +32°C. Under the substrate in which the eggs are located, there should be water in order to create the conditions as close as possible to incubation in the wild.

Everyone knows that the Nile crocodile is a super predator, which is not much inferior in size to the combed crocodile, which occupies the lead in the world. This predator lives in African countries. For many centuries, the large Nile crocodile has caused fear, as it is able to quickly and ruthlessly kill not only animals, but also people. The popularity of this species is also facilitated by the fact that its population is quite large and stable, although there are territories where such individuals are considered endangered.

The impressive size of the Nile crocodile allows it to hunt even animals larger than itself. The only exceptions are elephants and hippos. In length, adults can reach 5 meters, and their weight can vary from 225 to 550 kilograms. However, cases have been recorded when the length of the Nile crocodile reached over 6 meters, in particular, the largest animal 6.45 meters long was killed at the beginning of the last century in Tanzania. Interestingly, the smallest representatives of this species live in the south, and the largest in the center of the continent.

Physiological features

Nile crocodiles have a 4-chambered heart, which allows them to saturate the blood with oxygen as much as possible - if necessary, it can stay under water for up to two hours, while reducing the intensity of metabolic processes. Due to its slow metabolism and low body temperature, it does not require daily meals. At the same time, at one time, he can eat prey weighing half his own weight.

In the jaw of an adult there are 64-68 identical hollow conical teeth that change up to 50 times in a lifetime.

Representatives of crocodiles belonging to this family are distinguished by short legs, scaly skin with rows of bone plates, a very powerful honor and a strong tail. The organs of vision are located on top of the head, as well as the nostrils, so that the predator can be almost completely submerged in water for camouflage. There is also a third eyelid to protect the eyes from contact with water and glands that secrete "crocodile tears". The skin of Nile specimens is light brown at a young age with stripes of a dark shade in the tail and on the back, however, the color darkens with age.

What does the Nile crocodile eat?

Like all representatives of this species, the Nile crocodile is a predator. His diet consists only of meat.

Hatched crocodiles eat small insects and various aquatic invertebrates. After a few weeks, grown crocodiles are already beginning to eat larger prey: amphibians, reptiles, small fish and birds.

Reaching larger sizes, the crocodile hunts for larger prey. The diet of an adult Nile crocodile consists of fish and animals that come to drink. They successfully hunt African buffalo, zebras, giraffes, antelopes, warthogs, monkeys and even hyenas, leopards and lions. Crocodiles do not hunt only elephants, rhinos and hippos. Although the cubs of these animals can easily become a victim of the Nile crocodile.

The Nile crocodile is dangerous not only for animals, but also for humans. Every year, according to various sources, Nile crocodiles claim the lives of 1,000 people.

The crocodile waits for its prey near the shore, almost completely submerged in water. Seeing the intended victim, the crocodile abruptly jumps out of the water and grabs the prey with its powerful jaws. He inflicts deadly bites on his prey or drags him under water to drown him. Crocodiles do not disdain carrion, but they do not eat rotten meat.

Read more about the nutrition of other types of crocodiles in the article: .

Habitat of the Nile crocodile

The Nile crocodile lives on almost the entire African continent.

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

Now its habitat has been slightly reduced. 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, Côte d'Ivoire, Swaziland. The Nile crocodile is also found on nearby islands along the coasts of Africa: Madagascar, Socrates Island, the Cape Verde Islands, the archipelago of Sao Tome and Principe.

Reproduction of the Nile crocodile

The period of the mating season for the Nile crocodile in the north of the range falls during the dry season, in the southern part it coincides with the rainy season. At this time, the males are trying in every possible way to attract the attention of the female. They make different sounds, snort, roar, hit the water with their muzzle and even engage in deadly fights. The winner expels the opponent and is left alone with the female.

After mating, the female looks for a suitable place to lay her eggs. These are mostly sandy beaches along the riverbed. The female lays in one clutch from 20 to 100 eggs, in a hard calcareous shell, which develop for about 90 days. During this time, both parents are close to the masonry and guard the nest. When the period of the birth of offspring comes, the mother, having heard chirping sounds, breaks the masonry and helps the cubs get to the water. For the first 6-10 weeks, babies live in a shallow pond under the supervision of their mother. Then the kids disperse around the neighborhood, seeking refuge from predators and other crocodiles.

When they reach an older age, they leave their native places and look for a more suitable place of residence. On average, Nile crocodiles live 45-50 years, but there are also centenarians, up to 85 years old.

Varieties

The Nile crocodile is one of the species listed in the Red Book, so their population in their habitats is monitored. The appearance and physiology of crocodiles from different habitats can differ significantly, so they are divided into species: Ethiopian, East African, South African, West African, Malagasy, Kenyan and Central African.

The Nile crocodile is a representative of the class Reptiles or Reptiles. This animal is one of the most ancient, unique and dangerous on the planet. The predator is rightfully called the “king of the river”, because there are practically no equals to it in strength and adaptability. In this article you will find a description and photo of the Nile crocodile, you can learn a lot about this strong and greatest predator.

The Nile crocodile looks intimidating and belongs to the Crocodile family. He is huge, very strong and perfectly camouflaged. The predator has short legs that are located on the sides of the body, scaly skin, a long combed tail and powerful jaws. The eyes, ears and nostrils of a crocodile are at the top of the head. The reptile has exceptionally good hearing and vision.

The Nile crocodile looks inconspicuous due to its coloration. Juveniles are usually gray or light brown in color and have dark stripes on the back and tail. The older the individual becomes, the darker the color becomes. The belly of the reptile has a yellow tint. The massive muscular tail of the Nile crocodile serves as a kind of accelerator and allows you to move quickly in the water. It occupies almost half the length of the entire body of the reptile.

The jaw of the Nile crocodile contains 65 teeth and is one of the strongest on the planet. The predator can easily hold large animals and crush the bone.

Thanks to the sensory organs located on the top of the head, the crocodile can almost completely dive into the water. This allows the animal to camouflage itself in the water, leaving only the eyes and the tip of the nose on the surface, while its large and long body is hidden under water.

The Nile crocodile looks massive and is the largest crocodile. This predator is the second largest crocodile in the world. The males of the Nile crocodile are significantly larger than the females.

The average size of adult males ranges from 3 to 5 meters in length. In this case, body weight varies from 300 to 700 kg. Individual males can reach over 6 meters in length and weigh over a ton. The average size of females varies from 2 to 4 meters, with a body weight of 200 to 500 kg. But there are also some larger females.

Where does the Nile crocodile live? Behavioral Features

The Nile crocodile lives in Africa and is one of the largest crocodiles on this continent. It inhabits freshwater lakes, rivers and swamps almost throughout the entire territory of the African continent. It is most prevalent in African countries such as Kenya, Somalia, Zambia and Ethiopia. The number of the Nile crocodile is quite high and stable, but in some countries of the continent this species is endangered.

The Nile crocodile lives in calm waters, with sandy coastal areas. Not often it can be found at a considerable distance from the reservoir. This is usually associated with the search for a new habitat, as well as if the reservoir dries up. Most often, the crocodile crawls on its stomach, but can run short distances at speeds up to 14 km / h.

The Nile crocodile is very experienced and successful in swimming. It usually dives for 2-3 minutes, but can stay underwater for 30 minutes to 2 hours. It submerges completely and silently under the water, forcing the air out of its large lungs. The Nile crocodile swims very fast underwater. The tail helps to develop speed in water up to 30 km / h. Its ears, nose and throat are protected by valves, and its eye is covered with a thin transparent film. This predator has special receptors throughout the body. Thanks to which he easily picks up the vibrations of the water, and finds with what force and where they come from.

The Nile crocodile lives leisurely - they are usually quite slow creatures, like many other cold-blooded animals. Most of the time they are on the shore or in shallow water, keeping their jaws open to avoid overheating. Also, the opening of the mouth is a sign of threat to other crocodiles. Nile crocodiles are highly hostile and territorial predators.

Crocodiles can hibernate in summer, which lasts from May to August. To do this, they dig a hole on the bank of the river. Once underground, where it is dark and cool, the animal's body temperature drops and metabolism, respiration and heart rate slow down. In this state, energy is consumed minimally. So the crocodile will be able to save enough strength until he needs them.

For many centuries, a large Nile crocodile lives on the planet causing horror, because it is able to instantly and cruelly kill both animals and people. Among other animals, the Nile crocodile has no enemies. Only man is opposed to the predator. The Nile crocodile is hunted for its skin.

The Nile crocodile, combining its large size and high level of aggression, creates a very high probability of attacking a person. The Nile crocodile lives close to the underdeveloped population and often comes into contact with people. It can attack a person when he stands in the water near the shore, crosses shallow water, crosses a body of water, or puts his feet into the water from a ship or pier.

Less commonly, especially large and hungry Nile crocodiles can capsize a boat or even attack on land. Fishermen and people whose activities are related to water are most at risk. Also, careless hunters, tourists and travelers become victims of crocodiles.

Nile crocodiles often attack humans, while they are not afraid of people, and perceive them as potential food. Very dangerous are female crocodiles who protect their cubs. Anyone who tries to get close to the offspring will be eaten.

What does the Nile crocodile eat and how does it hunt?

Adult crocodiles are at the top of the food chain - there are no predators that would threaten them. This prehistoric animal eats everyone and everything in its path. The Nile crocodile is one of the strongest predators in the world. The Nile crocodile eats quite diversely. The crocodile is practically omnivorous. And the older and larger it is, the more food it needs and the larger its prey becomes.

Juveniles can make do with large fish and birds. As it gets older, the Nile crocodile feeds on larger animals that come to drink or cross the river. These are zebras, African buffaloes, wildebeests. It can attack elephants, rhinos, giraffes, hippos and even lions. Nile crocodiles hunt by submerging themselves completely, or leaving only their eyes and nostrils on the surface. He always attacks unexpectedly, jumping out of the water and almost instantly grabbing his prey.

In the water, the Nile crocodile is highly agile, using stealth, receptors, and strength to locate and capture its prey. It is virtually impossible to escape from it. It bites with an impressive force of 1 ton and tries to drown the victim. The jaws of the reptile are equipped with muscles that contract super fast, which makes the bite lightning fast and allows the jaws to snap at a speed of 9 m / s.

The Nile crocodile attacks prey at close range. It approaches and waits until the prey is within 2 meters of it. The crocodile jumps out of the water at a speed of 12 m / s, and its scaly skin makes it easier to maneuver in the water. The hind legs work like pistons and help push off the river bottom, and the long tail allows you to accelerate in the direction of the prey.

Their ability to successfully camouflage themselves underwater, combined with their high speed and explosive power, make Nile crocodiles excellent big game hunters. They can tolerate each other side by side and work as a group when attacking large prey.

The teeth of the Nile crocodiles allow you to hold the victim's body in the mouth and pierce it, but they do not know how to chew. However, this is not a disadvantage - the huge bite force and body power allow Nile crocodiles to easily break bones and cut through the body of a large animal, bite off limbs and drown. From a large carcass, they tear off pieces and swallow whole. Their stomach is adapted for the digestion of large food, in which anything is dissolved, thanks to the high concentration of hydrochloric acid.

When a group of Nile crocodiles divides large prey, some of them hold the carcass, while others rotate around their axis, pulling out large pieces of meat from it. This is called "death rotation". Relatively small animals, Nile crocodiles mercilessly swallow whole. On land, they are less mobile. They have a relatively slow metabolism and can go a long time without food. But if the opportunity presents itself, the Nile crocodile can eat half of its weight at a time.

Baby Nile Crocodile - Baby Crocodile Survival

During the mating season, males attract females in every possible way, making various movements and making various noises. Nile crocodiles become capable of breeding at the age of 10-12 years, reaching a body length of 3 meters for males and 2 meters for females. Large males are usually more attractive to females.

Egg laying time is from September to December. Sandy beaches and river banks are chosen for building nests. 2 months after a successful mating season, the female digs a hole up to 50 cm deep two meters from the shore and lays an average of 40-60 eggs.

After laying eggs, the female buries the nest for 3 months. She attacks anyone who tries to get close to the nest. Despite such protection, many nests are destroyed by other animals if the female leaves. When hatching, the Nile crocodile cubs begin to squeak and the mother breaks the nest. For many of them, the first moments of life are the last. Newborn Nile crocodile cubs have a body length of about 30 centimeters.

Nile crocodile babies are born at the very bottom of the food chain - anyone can eat them. The female carries her cubs from the nest in her mouth to the nearest body of water. The cartilages located in the mother's mouth allow the jaw to be locked at any moment of closing and to regulate the tension. The female can even block her mouth, which is only 5 cm open, which allows her to carry up to 20 cubs at a time without ever biting them.

The female has to make several visits, leaving the cubs in danger. While the females are gone, other predators prey on them. Less than half of hatchlings will survive the first month of life. But the surrounding danger and the age of one month cannot keep the cubs of the crocodile from what is inherent in them by nature - hunting and killing from the very beginning of their lives. They attack everything small that moves - insects, frogs, fish, cubs immediately grab them.

The mother takes care of the offspring for two years. In two years, crocodiles reach a size of 1.2 m and leave their native places. They are looking for a more suitable place to live, while avoiding the territories of older and larger crocodiles. The life expectancy of Nile crocodiles averages 45-50 years, but there are centenarians up to 85 years old.

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The Nile crocodile (lat. Crocodylus niloticus) is a large reptile of the family of real crocodiles. The largest of the 3 crocodile species found in Africa and the second largest in the world after the combed crocodile. Known as the man-eating crocodile due to its habitat, size and strength, it was an object of fear and worship in ancient times. Until now, it remains perhaps the most famous species of crocodiles. In general, the abundance of the species is relatively high and stable, although populations in some countries are under threat of extinction.

Appearance

Like all crocodiles, the Nile crocodile has short legs located on the sides of the body, scaly skin covered with rows of bone plates, a long strong tail and powerful jaws. Crocodile eyes are equipped with a third eyelid for added protection and have special glands that allow them to be washed with tears (hence the expression "crocodile tears"). The nostrils, ears and eyes are located at the top of the head, thanks to which the crocodile can almost completely submerge in water, leaving them on the surface.

The coloring of the Nile crocodile also allows it to go unnoticed. Juveniles are usually gray or light brown with dark stripes on the back and tail. With age, the color darkens and the stripes become less noticeable. The belly has a yellow tint, such skin is considered the highest quality.

Usually a crocodile crawls on its stomach, but can also walk with its torso elevated. Medium-sized individuals are able to run a short distance at a gallop, developing a speed of 12-14 km / h. It also swims quickly (30 km/h) making sinusoidal movements with its tail.

Physiology

The heart is four-chambered, like in birds, which makes it possible to saturate the blood with oxygen more efficiently. Usually the Nile crocodile dives for 2-3 minutes, but if necessary, it can stay under water for up to 30 minutes, and with reduced activity - up to two hours. Being a cold-blooded animal, it has a relatively slow metabolism and can go without food for a long time, but at the same time it is able to eat up to half its own weight in one sitting.

The Nile crocodile has fairly good hearing and a rich vocal range. His skin is equipped with special receptors that respond to changes in water pressure. The jaws have impressive strength, which allows them to hold large animals. Usually has 64-68 conical teeth - 36-38 on the upper jaw and 28-30 on the lower. Newly hatched crocodiles have a special tooth-like skin seal on the front of their snout that helps them get out of the egg.

Dimensions

The Nile crocodile is large, usually about 5 m, occasionally up to 5.5 m. The weight often exceeds 500 kg, there are individual specimens weighing over 1200 kg. The largest known specimen was killed in Tanzania in 1905: length 6.45 m, weight 1090 kg. Reports of 7-meter crocodiles have not been confirmed. At the southern border of the range - in South Africa, Nile crocodiles are somewhat smaller in size, their length usually does not exceed 4 m. Like other types of crocodiles, it exhibits sexual dimorphism - females are on average 30% smaller than males. In general, the differences are less than in many other species.

Crocodiles living in colder climates, such as southern Africa, are smaller - about 4 m. The pygmy Nile crocodile, living in Mali and the Sahara Desert, grows only up to 2-3 m. It is believed that such differences in size are the result of worse living conditions, not genetic differences.

reproduction

Under normal conditions, the Nile crocodile becomes sexually mature by the age of ten, when it reaches a length of 3 m for males, 2-2.5 m for females. During the mating season, males attract females by slapping the water, roaring, snorting, and making other noises. Large males are usually more attractive to females. During mating games, couples "sing" peculiar trills and rub the undersides of the muzzle.

The time of egg laying largely depends on latitude - in the north of the range it falls on the dry season, and in the south it is usually tied to the beginning of the rainy season - November or December. In Zimbabwe, females lay their eggs in September or early October. Favorite places for building nests are sandy beaches, dry riverbeds and river banks. The female digs a hole up to 50 cm deep two meters from the shore and lays from 20 to 85 eggs (average 50). Several females may build nests close to each other.

After laying eggs, the expectant mother covers the nest with sand and guards for a 3 month incubation period. The father is usually nearby as well, and both parents will attack anyone who tries to get close to the nest. Despite such care, many nests are destroyed by people, monitor lizards and other animals if the mother leaves to hide from the heat or take a dip in the water.

Hatched cubs make chirping sounds, and at this signal, the mother breaks the nest. Parents sometimes take the eggs in their mouths and squeeze them between the tongue and palate to help the offspring free themselves. Then the female leads the crocodiles to the water or carries them in her mouth.

As with other crocodiles, the sex of the young is determined by temperature during the middle third of the incubation period, not genetically. If the temperature inside the nest was below 31.7 ° C or above 34.5 ° C, then females are born, otherwise males.

Newly hatched crocodiles have a length of about 30 cm, in the first years they grow quite quickly. The mother takes care of the offspring for two years. If several nests were close to each other, mothers can take care of their offspring together, forming a kind of crocodile nursery. In two years, young crocodiles reach a size of 1.2 m and leave their native places, while avoiding the territories of older and larger crocodiles. The average life expectancy of Nile crocodiles is 45 years, there are specimens up to 80 years old.

Food

Newly hatched crocodiles feed on insects and aquatic invertebrates, moving on to amphibians, reptiles, and birds fairly quickly. The diet of even adult crocodiles is 70% fish and other small vertebrates, despite the fact that a crocodile can eat almost any animal that comes to a watering hole, with the exception of adult elephants and hippos. The Nile crocodile also eats carrion, although it avoids rotten meat. A group of crocodiles can go hundreds of meters from the shore to get to the corpse of a large animal.

An adult crocodile uses its body and tail to push a school of fish towards the shore and eats it with a quick movement of its head. Crocodiles can also form a group and block migrating fish by becoming a semi-circle across the river. In this case, the dominant crocodiles eat first.

It is known that Nile crocodiles can successfully attack zebras, antelopes, buffaloes, young hippos and rhinos, giraffes, warthogs, hyenas, monkeys, felines, as well as other crocodiles. The ability to hide almost completely under water, combined with high speed over short distances, makes crocodiles good hunters of large prey. They grab it with powerful jaws, drag it into the water and hold it there until it drowns. When the prey is dead, they tear off pieces from it and swallow it. When dividing the joint prey, they coordinate efforts to break the body, and for this purpose they can also push it under snags or stones.

The Nile crocodile poses a danger to humans, although to a lesser extent than the combed crocodile. Females are especially dangerous during the period of caring for offspring, when they become especially aggressive towards any animal approaching the nest. Most attacks take place far from civilization and are not recorded, so the real number of victims is unknown. According to some sources, it is 1,000 people a year, according to others - 200. In 2005, a crocodile was caught in Uganda, which, according to local residents, ate 83 people in 20 years. In 2006, in Botswana, a professor of medicine at the University of Washington, Richard Root, became a victim of a crocodile.

The Nile crocodile is thought to have a symbiotic relationship with some birds, such as the spurred lapwing (Vanellus spinosus). According to some reports, the crocodile opens its mouth wide, and at this time the bird takes out pieces of meat stuck in its teeth. However, these reports have proven difficult to verify and may not be a true symbiotic relationship.

Distribution and protection

The Nile crocodile prefers to live along the banks of rivers and lakes and in freshwater swamps, sometimes found in brackish water, in estuaries or mangroves. It is distributed throughout almost all of sub-Saharan Africa, as well as in Madagascar and in the Nile basin. Once lived much further north - the fossil remains of this animal were found in Algeria, Israel and Jordan, as well as in the Comoros.

In the 1940s - 1960s, the Nile crocodile was actively hunted, mainly because of the high quality skin, to a lesser extent because of the meat and the alleged medicinal properties of its organs. This led to a multiple reduction in the number of the species, as a result of which there was a threat of its extinction.

The Nile crocodile is widely distributed in many countries of southern and eastern Africa, such as Somalia, Ethiopia, Kenya, Zambia, the population is controlled and documented.

The Nile crocodile is listed on the Red List of the World Conservation Union for the category of minimal risk. The trade in crocodiles is regulated by an international convention according to Appendix I of CITES.