How long do crocodiles live. Crocodile animal

And snakes combined. It is believed that in Africa every year about a thousand people, mostly children and women, become victims of these animals. Crocodiles can be found in Central and South Africa, in hot regions of Asia, on the islands Pacific Ocean lying in the tropical zone, and in the north of Australia. They are also found in the tropics of South America, but the alligator is more common there. (It is not difficult for any naturalist to cite many features that distinguish a crocodile from an alligator. We will refer to the most characteristic difference. In an alligator, if the mouth is closed, the teeth are not visible. In a crocodile, two long fangs are visible. They seem to rest in the grooves of the upper jaw and create the appearance of a smile).

If you do not take into account several species of tiny ones from the family, then of all the reptiles, only the crocodile has a "voice". His strange, thick roar resembles either distant peals of thunder, or the beat of a bass drum. Crocodile teeth have amazing ability restore. As soon as a tooth falls out, a new one grows in place of the fallen one. And so all my life. The crocodile is not picky. Its gastric juice is so rich in hydrochloric acid that iron arrowheads and even steel hooks dissolve in it in a few months. But, despite this, observations show that the appetite of the crocodile is small. In captivity, only 400 grams of meat per day is enough for him.

The crocodile has two formidable weapons: terrible jaws and a powerful tail. With one blow of the tail, he can kill an adult antelope or break her leg. Most often, the crocodile stays near the shore. Muddy waters hide a predator. He dives silently. And then it rushes at the victim, capturing it, as if in a trap, with its toothy mouth.

The eyes and nostrils, located very high, are barely visible on the surface of a lake or river. The body of the crocodile is under water. Like a submarine, the crocodile is equipped with an amazing system of valves that automatically close the nostrils, ears and throat when diving. The crocodile's eyes are unusually sensitive to light, which allows it to see clearly underwater even at night.

The crocodile is one of the few predators that boldly and systematically attack humans. In those places where it is sacred (it is fed there), where the waters are teeming with fish, the crocodile is almost not dangerous. But in others, where there are few fish and game, he is not averse to feasting on human meat. Most often, women are victims of crocodiles when they wash clothes on the river bank or come for water, and bathing children.

When a crocodile manages to grab some large animal, such as an antelope or, it deprives the animal of balance with skillful movements of the head, and then drags it into the water for deep place and drowns. It would seem that you can start the feast, but there are some difficulties. The fact is that the teeth of a predator are not adapted for chewing. They serve him only as an instrument of capture. Therefore, the crocodile deals immediately with only small animals.

The crocodile drags large animals away from the coast and waits until the carcass deteriorates and becomes softer. Only then does he tear her apart. Often, the crocodile drags its prey into a cave dug under the shore. A kind of tunnel usually leads into it from the water. And through a small hole that goes to the surface of the earth, air enters the cave.

Here is an unusual case that happened to one African. A crocodile grabbed him by the leg and dragged him to the bottom in front of those present. Luckily for the victim, the crocodile's hiding place was only a few meters away. The unfortunate man came to his senses in a cave. Skeletons and decaying carcasses surrounded him. The crocodile lay nearby. But soon the water began to boil, and he disappeared. Then the African, taking advantage of the absence of a predator, tore open a hole with his hands through which air flowed, and fled. At home for a long time they refused to believe the "newcomer from the world of shadows." (By the way, it would be possible to make good films about Africa with crocodiles in the title role).

There are many varieties of crocodiles. The most common Nile crocodile lives in Africa and Madagascar. The female of this crocodile carries an average of 55 eggs. The length of each reaches 8 centimeters. She buries her eggs near the water in the heated sand and patiently waits for the offspring to appear. The wait is about three months. All this time, the female guards the eggs from robbers: mongoose, pythons, hyenas, and monitor lizards (sometimes people eat crocodile eggs, but the eggs smell like fish).

When crocodiles are born from eggs, buried under a layer of sand 50 centimeters deep, they cannot break the shell in any way. Then they begin to call their mother, who seemed to be just waiting for the SOS signal. The female immediately begins to rake the sand. This instinct is extraordinarily powerful. One day scientists conducted an experiment. They fenced off the egg-laying place with a wooden fence. At the first distress signal, the female smashed the fence to pieces.

A newborn is small - some 25 centimeters. But from the moment of birth, he shows a rare aggressiveness, sinking his teeth into everything that comes his way. Having hatched from the egg, the newborn immediately rushes to the water, seeking salvation from many birds and animals there - storks, cranes, adult crocodiles, which find the meat of young predators. tastier than eggs. After counting all his enemies, some experts argue that out of a hundred newborns, only one manages to survive to adulthood.

Crocodiles live a hundred or more years. They are among those rare animals that grow until death, but with age their growth slows down. It is said that the crocodiles of the Pacific Islands and Asia happen to reach 9 meters. As for the Nile crocodiles, recent times no hunter can boast of having killed a crocodile longer than five and a half meters.

And the number of hunters is growing. Prices for shoes, bags and suitcases made of crocodile leather are rising, but demand is not decreasing. The toothy creatures that came out victorious in the fight against the centuries, according to experts, lived on the planet a hundred million years ago, and now they are dying from the bullets of civilized hunters. Naturally, predatory lizards disappear. Scientists predict the imminent extinction of the Nile crocodile. But few share their concern. Hunters claim that crocodiles simply move to inaccessible areas, fleeing the noise of civilization and the restless neighborhood with humans.

African countries have a different opinion. Many of them have limited hunting for crocodiles (created nature reserves). So, on Lake Victoria in Uganda lives great amount crocodiles, the largest in Africa, and maybe in the world. The waters of the lake are teeming with fish, and a hungry crocodile only has to open its mouth to get enough. Crocodiles lie on the shore. Sometimes so tightly that some settle on the backs of their fellows. They look like fallen trunks of ancient trees, burned by time.

Plan
Introduction
1 Description
1.1 Appearance
1.2 Physiology
1.3 Dimensions

2 Reproduction
3 Nutrition
4 Distribution and protection
5 Nile crocodile as an object of sport hunting
6 Cult of the Nile crocodile
7 Classification
Bibliography Introduction Nile crocodile (lat. Crocodylus niloticus) - 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 selected countries are in danger of extinction. 1. Description 1.1. 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. 1.2. 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. 1.3. 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 smaller than in many other species. Crocodiles living in colder climates, such as southern Africa, are smaller - about 4 m. The dwarf 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, and not genetic differences. 2. Reproduction AT 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 the construction of nests - sandy beaches, dry channels 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 can 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 dip in the water. The 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. The female then leads the crocodiles to the water or carries them in her mouth. As with other crocodiles, the sex of the cubs is determined by temperature during the middle third of the incubation period, and 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. 3. Nutrition 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 willingly eats carrion, although it avoids rotten meat. A group of crocodiles can travel hundreds of meters from the shore to reach the carcass of a large animal. An adult crocodile uses its body and tail to push a school of fish towards the shore, and grabs 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. At the same time, dominant crocodiles eat first. It is known that Nile crocodiles can successfully attack zebras, antelopes, buffaloes, young hippos and rhinos, giraffes, warthogs, hyenas, monkeys, cats, and other crocodiles. The ability to almost completely hide under water, combined with high speed at 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 sharing joint prey, they coordinate efforts to break the body, and can also push it under snags or stones for this purpose. The Nile crocodile is a danger to people, although to a lesser extent than 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. It is believed that the Nile crocodile has 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. 4. 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 widespread in many countries of southern and East Africa, such as Somalia, Ethiopia, Kenya, Zambia, the population is controlled and documented. The Nile crocodile is listed in the "Red List" of the World Conservation Union in the category of minimal risk. The crocodile trade is regulated international convention according to Appendix I of CITES. 5. Nile crocodile as an object of sport hunting In many countries where stable populations of Nile crocodiles are preserved, they are allowed to hunt according to quotas. The main way to hunt a crocodile is to lie in wait at the bait. For bait, as a rule, strongly rotten pieces of meat or a whole carcass of a small animal (antelope, goat, baboon, etc.) are used, which are placed so that the crocodile, getting to the meat, gets out of the water. At some distance from the bait, an ambush is arranged - usually a grass hut. Crocodiles are extremely careful, so they put the hut at a distance of 70-80 meters from the bait. Crocodiles notice extraneous sounds well, in addition, they can pay attention to the unusual behavior of birds that see a person. This requires the hunter to be able to sit in an ambush quite quietly and imperceptibly. Unlike many other predators, the crocodile is active in relation to the bait at any time of the day. Shooting is carried out only at a crocodile that crawled ashore. Hunting the Nile crocodile requires a fairly powerful weapon (caliber, for example, .300 Win Mag or even .375 H&H Magnum), but in addition, the weapon must have high accuracy and accuracy. The kill points of a crocodile are extremely small - small areas on the head and neck. The hit requires high accuracy due to the fact that the crocodile must be put immediately on the spot and not allowed to go into the water - a killed crocodile always drowns, but it is extremely difficult to pull it out. 6. The cult of the Nile crocodile The inhabitants of Ancient Egypt worshiped the god Sebek, who was associated with fertility, protection and the power of the pharaoh. The attitude towards him was ambivalent: sometimes they hunted crocodiles and insulted Sebek, sometimes they saw him as a protector and source of the pharaoh's power. Sebek was compared with the earth god Geb, the solar deity Ra and Osiris. Sebek was depicted as a crocodile, a mummy of a crocodile, or a man with the head of a crocodile. The center of his cult in the Middle Kingdom was the city of Shedit, which the Greeks called Crocodilopolis, and even later Arsinoe. Another large temple of Sebek was in the city of Kom Ombo, and many smaller ones were in many other cities of Egypt, mainly in Upper Egypt and the Nile Delta. Herodotus wrote that in the 5th century BC. e. some Egyptians kept crocodiles as pets. In the pool of the temple of Sebek at Arsinoe lived a crocodile, where he was fed, adorned with jewels and worshiped. When he died, his body was mummified, placed in a sarcophagus and buried in a tomb. A number of mummified crocodiles and crocodile eggs have indeed been found in ancient Egyptian graves. Several well-preserved mummies are in the Cairo Museum. In order to appease the crocodiles, Ancient Egypt special spells were used. Even in modern Nubia, fishermen hang a figurine of a crocodile over the threshold of the house to protect against evil. Worship of the Nile crocodile is also common among many other peoples of Africa. In some areas of Burkina Faso, the Nile crocodile is a sacred animal. According to the religious beliefs of the Mosi people, more than half of whose representatives live in this country, every person has a soul in the form of an animal - a snake, an antelope, a hare or a crocodile. To kill this animal on the territory of the village means to kill a person whose soul has its appearance. 7. Classification Depending on the region and external features several subspecies of the Nile crocodile are distinguished.

Crocodylus niloticus africanus

Crocodylus niloticus chamses

Crocodylus niloticus corviei

Crocodylus niloticus madagascariensis

Crocodylus niloticus niloticus

Crocodylus niloticus pauciscutatus

Crocodylus niloticus suchus

DNA analysis conducted in 2003 revealed differences in different populations of the Nile crocodile, suggesting a possible division of the species. Thus, the populations of West and Central Africa are already considered by some authors as a separate species. Crocodylus suchus . Bibliography:

Allen E Greer.

Journal of Herpetology

Jamie Richard Oaks.

M.S. thesis, Louisiana State University

Encyclopedia Britannica

David Quammen.

N. S. Flint, F. H. van der Bank, J. P. Grobler.

Water S.A.

Adam Britton

Crocodilian Biology Database

Adam Britton

Crocodilian Species

national park

Amélie L. Vergne, Alexis Avril, Samuel Martin, Nicolas Mathevon.

Naturwissenschaften

A. Aulie, T. I. Kanui.

Comparative biochemistry and physiology

Denis Charles Deeming.

S. V. Mezhzherin.

Genetics

animal bytes

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Christopher P. Kofron.

Amphibia-Reptilia

Christopher P. Kofron.

African Journal of Ecology

Tom Paulson

Alvin Silverstein, Laura Silverstein Nunn.

Species Accounts

Geraldine Harris, Delia Pemberton.

Herodotus.

Animal Mummy Project

Carol Andrews Carol Andrews Raymond Oliver Faulkner Raymond Oliver Faulkner

Richard Bangs.

Richard Ferguson.

IUCN SSC Crocodile Specialist Group

Christopher D. Roy

Crocodylus niloticus

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

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 in size only to the combed crocodile.

The main food of an adult Nile crocodile are various small and large mammals:, reed rats, otters, bush cats, viverras,. Large prey are various species (waterbucks, impalas, kudu, gazelles), large forest, aardvarks, African manatees, as well as all types of domestic animals that accidentally wandered into a watering place. The largest Nile crocodiles attack buffaloes, cubs and, on, brown hyenas and big cats.

Also, Nile crocodiles eat carrion, steal food from, and hyena dogs. A predatory reptile has a slow metabolism, so the animal can starve for a long time, but with a successful hunt, the amount 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, feed little.

Reproduction of Nile crocodiles

Sexual maturity of Nile crocodiles occurs at the age of 12-15, when males grow up to 2.5-3 m, and females up to 2-2.5 m in length. The onset of the mating season depends on the habitat: the northern part of the population breeds in 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 rival. Crocodiles exhale noisily through their mouths, make growling or grumbling-like sounds, and blow bubbles with their open mouths. Simultaneously with these demonstration actions, excited by the struggle for the future female, the Nile crocodiles bend their necks, raise their tail, whipping it over the surface of the water. Having admitted defeat, one of the males turns around and high speed swims away, trying to get away from the pursuit of a competitor. If it is not possible to escape, the losing crocodile raises its head high, opening access to the throat: this position is a sign of appeasement and recognition of defeat. The victorious crocodile sometimes grabs one of the opponent's limbs with its jaws, but does not bite it. Such "premarital" fights allow you to expel extra males from the territory chosen by a pair of crocodiles.

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

Sandy beaches and shallows, dried up channels and river banks become a place for laying eggs. Not far from the water's edge, the female Nile crocodile digs a nest up to 60 cm deep and lays 20 to 95 eggs (usually about 55-60). The female vigilantly guards the buried masonry throughout the entire incubation period, which is approximately 90 days. Periodically, the male helps her, and the couple rebuffs anyone who poses a threat to offspring. Occasionally, the female is forced to hide from the heat, and the nest of the Nile crocodile left unattended is ruined 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 until the end of incubation.

Taken from www.africawildtrails.com

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

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

The sex of the Nile crocodile cubs, like any other crocodiles, is formed under the influence of temperature inside the nest during the second month of incubation: at a temperature of 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 avoid meeting with large representatives of the species until puberty.

Young crocodiles dig holes up to 3.6 meters long in the banks, which serve as a refuge for them up to 5 years of age. Adults also dig similar holes for themselves under the roots of trees hanging over the water.

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.

The Nile crocodile is a reptile, from the family of crocodiles, the second largest, after the saltwater comb.

Living in the rivers, lakes and swamps of central and southern Africa, this ancient ferocious predator, devours almost all living things that come across it on the way.

In terms of size, the Nile crocodile is simply a giant, on average its length is from 5 to 5.5 meters, and its weight often reaches a ton. This is the largest crocodile living in our time in Africa.

Description and lifestyle

The Nile is the most ancient animal in Africa. According to scientists, it has existed on earth for tens of millions of years and is a descendant of a prehistoric archosaurus, a contemporary and relative of the dinosaur and beast lizard. The appearance of this semi-aquatic monster speaks for itself. A huge elongated body, covered with ossified plates, on short crooked legs, a powerful vertically flattened tail, a large flat head and a huge mouth with jaws studded with numerous wedge-shaped teeth, betray in it a strong and ruthless predator, which it essentially is.

For a long time, these crocodiles have bred in the waters of almost all of Africa. south of the desert Sahara. This was facilitated by a favorable warm climate, a large amount of water, a lot of vegetation and, as a result, a rich fauna in abundance that provided crocodiles with food. For many years of living in these fertile places, the Nile crocodile has become the most big predator Africa, which everyone began to fear, both animals and people.

In ancient times, being helpless against the incredible power of this ferocious monster, people equated it with a deity capable of either benevolent or punishing a person. He was prescribed the ability to control the waters of the Nile, the main water artery Egypt. This is how the cult of the god Sebek appeared, a creature with a human body and a crocodile head. This was beneficial to the power of the pharaohs, and they contributed to the creation of a whole system of planting and maintaining this cult. Pharaoh Ptolemy II even built a whole temple of this deity in the city of Shedite, later renamed Crocodilopolis by the Greeks, which was the center of worship for this deity. In this temple, the Nile crocodile was kept in luxury as the earthly incarnation of the god Sebek. This went on for many centuries, and since not a single crocodile could live so long, it was periodically changed, and the bodies of the dead crocodiles were mummified and stored in specially made sarcophagi. All this ended only with the arrival of the Romans in Egypt.

Whatever it was in ancient times, ordinary Nile crocodiles still exist today, and very well. They live in massive colonies in the valleys of large African rivers, where herds of wild animals are still preserved, which always come to the water, which crocodiles need. Crocodiles cannot chase antelopes across the savanna, although juveniles basking in the sun sometimes try to show agility by rushing at an antelope, zebra or young buffalo that comes close, but they very rarely succeed. The tactics of adult crocodiles is that they calmly, hiding in the water up to their very nostrils and eyes, wait for a herd of these harmless animals to come to a watering hole and start drinking water. Then, almost silently, the crocodile swims up to the intended victim, with a sharp blow of the tail against the bottom, throws its body forward and grabs the animal that did not have time to jump back. There was an antelope and not.

The second option is when herds of animals begin to migrate, changing pasture locations. Then they are simply forced to cross the river, where only agility and speed can save them. Who did not have time, that expects death from crocodile teeth. Although crocodiles are very ferocious, they never hunt for future use. If a crocodile has caught an antelope or a zebra, then he will take care of his meal and he does not care about other animals running nearby. So the animal that died in the teeth of a crocodile, by its death, makes it possible for fellow tribesmen to stay alive. In addition to animals, Nile crocodiles do not disdain birds and turtles, in principle, all that they come across are monkeys, and porcupines, and pigs, and all other living creatures. Among the crocodiles there are also their own, so to speak, "thugs", who rush to animals that are much larger in size, such as hippos or elephants. And, oddly enough, sometimes they succeed, although the crocodile most often cannot cope alone with a multi-ton elephant or hippopotamus. Cases of attacks by the Nile crocodile on humans are not uncommon, therefore, in some African countries he was called the cannibal crocodile.

Nile crocodiles are one of the long-livers of the Black Continent. On average, the Nile crocodile lives for about 40 years, but in favorable conditions it can live up to a hundred years, although usually only a few succeed. These large crocodiles have almost no enemies other than lions and humans. Well, if lions are faced mainly by units of the crocodile tribe, then people are a threat to the entire crocodile family. Due to the high demand for the skin of the Nile crocodile, for many years they were ruthlessly killed and in some countries they are under the threat of complete extinction. Now their population is more or less stable in Egypt, Somalia, Ethiopia, Zambia, Kenya, Morocco, and on some islands: Madagascar, Mauritius, Cape Verde, Zanzibar, mainly due to the creation national parks, where hunting for them is prohibited, and for the reproduction of the skin, they create special farms for growing crocodiles.

The number of crocodiles is replenished by the peculiarity of their reproduction. During the mating season, the female Nile crocodile lays 50-60 eggs. Of course, not all of them hatch, because there are many people who want crocodile eggs, such as hyenas, baboons, and people too, but the crocodile keeps at least a couple of dozen cubs until next year. And if not for hunting them, they could well be a serious threat to the population of Africa. It seems that this decline somehow also maintains a balance in nature, although now the Nile crocodile is listed in the Red Book.