Where does the giant monitor lizard live? Komodo dragon

The gray monitor lizard is a large creature. The maximum length of its body can reach one and a half meters. And the body, by the way, takes up only a third. The remaining length is “occupied” by the tail. Weight Limit can reach 3.5 kg. But such cases are rare. Males, as is usually the case in the animal world, are larger than females. However, not harder.

The gray monitor lizard, the photo of which is provided above, has a very interesting color. Although, judging by the name, it doesn’t seem so. In fact, it appears more sandy or light brown than grey. There were also numerous dark spots and specks with which the upper part of the body of these creatures was “strewn”. The neck is characterized by 2-3 longitudinal dark stripes, which connect at the back and seem to form a horseshoe-shaped pattern.

It is interesting that in “youth” the gray monitor lizard always looks brighter than in older age. General background juveniles have a yellow tint, and the dark stripes appear not brown, but almost black.

Features of physiology

The slanting, slit-like nostrils of these lizards are located quite close to the eyes. This structure makes it easier for the monitor lizard to explore burrows, since the nostrils are not clogged with sand in the process. This is important because the gray monitor lizard hunts mainly rodents that live in burrows. Its victims are jerboas, gophers, and gerbils. Sometimes, however, lizards hunt geckos, young snakes and turtles. In general, they have a rich diet. Sometimes these creatures even attack snakes and However, about hunting - a little later.

The gray monitor lizard is a reptile with strong, sharp teeth that are slightly curved back. With them he holds his victim. Teeth are constantly renewed. Throughout the life of a lizard, several pairs of them are erased. By the way, the gray monitor lizard does not have teeth cutting edges. But despite this, he is still capable of killing large animals and eating them, swallowing them whole, although not without effort.

Hunting

So, above we have listed what the gray monitor lizard eats. Now we can say a few words about exactly how this creature hunts.

If a lizard has chosen a large snake as a victim, it will adhere to certain tactics. First, he will tire her with false attempts to attack - he will make approaches from different sides, like a mongoose. And then, when the snake gets tired, it will jump on it and grab its head with its teeth (or a little further). Immediately the monitor lizard will begin to shake the victim and hit it against the ground or stones. He needs the victim to stop resisting. Sometimes, to do this, he can simply hold it in his teeth, squeezing his jaws until the snake weakens. Nothing will happen to the monitor lizard from the response (bite). If the snake tries to “wrap” the hunter in a ring to strangle him, he will easily dodge.

When a monitor lizard hunts, it tries to stick to an already proven route. During his “research” he checks rodent burrows, bird nests, and gerbil colonies. However, if nothing can be found, the reptile will not disdain carrion.

Habitat

The countries in whose territory the gray monitor lizard can be found have already been listed above. Peculiarities appearance allow him to remain unnoticed - he is ideally camouflaged in the sand, and on trees, and between stones, and in the ground. By the way, the northern border of the habitat reaches the coast of the Aral Sea (on the border of Uzbekistan and Kazakhstan). This lizard is most rarely found in the valley near the Central Asian

As a rule, gray monitor lizards large quantities live where many small mammals can be found. The Turkmen village of Garametniyaz is considered such a place. More precisely, the territory next to it - there, for every square kilometer, the density of gray monitor lizards ranges from 9 to 12 individuals.

Lifestyle

Deserts and semi-deserts are where the gray monitor lizard is most often found. What are the features of his appearance - it was said at the very beginning of the article, and with this appearance he can easily hide from more predatory animals. Most often, these lizards can be found on semi-fixed or fixed sands, and a little less often on clay soils.

Monitor lizards try to stick to river valleys, foothills, ravines, and tugai thickets. And they cannot be found in areas where there is dense vegetation. True, they visit rare forest areas. But they will certainly never live in those places that are adjacent to human habitations.

Gray monitor lizards take refuge in the same burrows where turtles and rodents used to live. They can “settle” in a hollow or bird’s nest. But they look for ready-made housing, as a rule, in clay deserts. Because it is difficult for them to dig their own hole there. But in sandy deserts- No. There, monitor lizards dig holes, the depth of which can reach several meters. They hibernate there during the winter. And so that no one gets into the hole, they close it with a plug made of earth.

Activity

Monitor lizards can only be seen during the day, and only if it is not too hot outside. If the thermometer goes off scale, the lizard will hide in a shelter. Normal temperature their body temperature ranges from 31.7 to 40.6 degrees maximum.

Monitor lizards - quite quick creations. They move at a speed of 100-120 meters per minute. That is, they can cover 7.2 kilometers in an hour - and this is one and a half times more than a person can walk at a normal pace. Although these lizards travel only a little more than 10 kilometers per day. They move long distances from their burrow, but always return back.

Monitor lizards easily climb trees and often enter bodies of water. There is an assumption that they can mark their territory - this happens in the summer and spring. However, not all biologists think so, so the fact is considered controversial.

Enemies

Gray monitor lizards have virtually none of them, if we talk about natural environment a habitat. The only enemy of this lizard is man. Although young individuals are often attacked by black kites, snake eaters, jackals, corsacs and buzzards. Larger lizards can also attack the gray monitor lizard. And if he notices danger, he will reach speeds of up to 20 km/h to break away from pursuit. But if it doesn’t work out, it “swells up”, becomes flat and wide, begins to hiss and stick out its long forked tongue far. Which, by the way, is its additional olfactory organ.

If the enemy is not afraid and continues to advance, the monitor lizard begins to whip its tail and rush at the aggressor. He may also bite, although this is the last technique he resorts to. Because the teeth of a monitor lizard can cause severe pain, leading to an inflammatory reaction. Lizards are not poisonous, but certain toxic components are present in their saliva.

What else is worth knowing?

Everyone knows that there are many people who like to keep exotic animals at home. No one keeps gray monitor lizards in apartment conditions, because they require special care. And only the person who knows by heart can provide it. physiological characteristics this lizard.

Interestingly, Muslims are wary of gray monitor lizards. Their name in Turkic sounds like “kesel”. Translated given word like "disease". And people believe that meeting a monitor lizard promises misfortune.

At one time, these creatures were on the verge of extinction. Many found the skin of monitor lizards unusually beautiful, which is difficult to disagree with. In addition, it is very durable. And monitor lizards were killed en masse to make shoes, wallets, bags and other accessories from their skins. At the beginning of the 20th century, 20 thousand individuals were destroyed per year. Then people realized what a horror they were committing and stopped killing these creatures. This is encouraging, although there are not as many representatives of the species left as before - in some places monitor lizards have already become extinct.

Monitor lizards are the largest lizards in the world. In size, some of them are not inferior to crocodiles, although they are not related to them. Systematically, monitor lizards are closer to snakes than other lizards. These reptiles are classified into a separate family of monitor lizards, which includes 70 species.

Gray monitor lizard (Varanus griseus).

All species of monitor lizards are medium or large in size, the smallest of them, the short-tailed monitor lizard, reaches a length of only 20 cm, but most of these reptiles have a length of 0.5-1 m. The most large monitor lizard- Komodo dragon (Komodo dragon, Komodo dragon) reaches a length of 3 m and weighs up to 140 kg! Exactly gigantic size This lizard prompted people to call this species a dragon. In addition to their large size, monitor lizards differ from other lizards in their well-developed muscles, their paws are not only tenacious, but also strong, their stomach is widened in the middle part, their tail is muscular, whip-shaped and very long. Most monitor lizards have a tail that is as long as their body. Unlike real lizards, monitor lizards cannot throw their tail away in case of danger, but they can whip it from side to side. The muzzle of monitor lizards is bluntly rounded, but its features are more reminiscent of snakes than lizards. True, unlike snakes, monitor lizards have round eye pupils. The scales on the body are relatively large, rounded, the fingers end in long claws. The tongue at the end is forked like a snake’s, with its help monitor lizards can smell odors at a great distance (this is also a typical snake sign). In addition, the skin on the neck of many species can become very swollen. The coloring of monitor lizards is often dim, with gray, sand, black, and brown tones predominating. Many monitor lizards, especially young ones, have spotted and striped colors.

Emerald monitor lizard (Varanus prasinus) is the most bright look. This monitor lizard lives in tropical forests and the green color performs a camouflage function.

Monitor lizards - residents warm countries, almost nowhere does their range extend beyond the tropics and only the gray monitor lizard in the north of its range lives in temperate zone(V Central Asia). Monitor lizards have reached the greatest species diversity in Australia and on the adjacent islands; these animals are also found in South and Central Asia and Africa. They do not live in the New World. The ranges of most species are extensive, but the Komodo dragon lives only on the Indonesian island of Komodo. This is the rarest and smallest species.

The habitats of monitor lizards are varied; according to their ecological preferences, they can be divided into two groups. Some monitor lizards prefer arid desert areas; they are found in dry bushes, woodlands, savannas, semi-deserts and real quicksand. Other species prefer to stay close to water; they live on the banks of reservoirs in tropical forests. Finally, there are monitor lizards that prefer woody vegetation And most spend time in the trees. However, monitor lizards of other groups are also excellent climbers.

Monitor lizards are active all year round and only the gray monitor lizard in the north of its range hibernates in the winter. Burrows serve as shelter for him, which he seals with an earthen plug for the winter. Other species also dig burrows and spend the night in them. The monitor lizard's burrow is up to 2-2.5 long, and a large Komodo dragon is up to 5 m long! A person can freely climb into such a hole. Monitor lizards are sedentary animals, but they do not adhere to strict boundaries of their territories. Most of the time they are actively searching, covering a large area during the day. The movements of monitor lizards are not similar to the movements of nimble real lizards. When walking, they strongly bend their spine and thus resemble crocodiles. However, the sprawling movement is just an illusion of clumsiness; if necessary, monitor lizards can run quickly, climb the branches of trees and bushes, most species are good swimmers.

The mottled monitor lizard (Varanus varius) reaches a length of 2 m and is famous for its ability to climb trees.

Monitor lizards live alone and have a quarrelsome character. Having met at the prey, they immediately enter into a fight. Monitor lizards threaten their opponent with a loud hiss, strongly inflate their belly and lash with their tail. U large species the blow of the thin but strong tail is like the blow of a whip; it is very sensitive even for a person. Komodo dragons are more relaxed towards relatives of equal size (smaller ones are driven away); sometimes they can share a meal with large prey.

Monitor lizards are active predators. They are not picky about food and will catch almost any animal of suitable size. Depending on the place of residence of a particular species, their prey includes small lizards, snakes (including poisonous ones), young turtles, small mammals (gerbils, hedgehogs, platypuses), and insects. Monitor lizards readily feast on the eggs of crocodiles, birds, turtles, and snakes and regularly check the sites of possible clutches. Monitor lizards look for their prey in two ways: they look for prey while walking around the territory and chase it at a run (mobile, but not too frisky species) or find it by smell (sedentary animals, eggs, carrion). Monitor lizards sense odors from a great distance and accurately determine their source, constantly sticking out their tongue and sniffing the air with it. This search method is not typical for real lizards, but is typical for snakes. Monitor lizards either swallow their prey whole or tear off pieces with their mouths, holding them with their front paws.

The Komodo dragon (Varanus komodoensis) has a thick, inflexible tail that is not used for defense.

Due to their large size, Komodo dragons eat special foods. The basis of their diet is carrion, primarily the corpses of large animals - wild pigs and deer. However, carrion in nature is a “scarce” product. In this regard, Komodo dragons have developed tolerance towards their relatives when eating prey and... the ability to kill their prey. Of course, it is difficult for a heavy monitor lizard to catch up with a fast-footed deer, but he does not have to catch it, just bite him, and in a couple of days the table is ready. Even a light bite from the Komodo dragon is fatal, which has given rise to talk about the poisonousness of this species. However, these monitor lizards do not have real poison, but they do have a unique substitute. The saliva of Komodo dragons is very viscous and pathogenic bacteria multiply in it; their food is small pieces of food stuck between the teeth of the monitor lizard. The owner of the bacteriological weapon himself does not suffer at all from such flagrant unsanitary conditions in his mouth, but when bitten, the bacteria enter the victim’s wound and cause blood poisoning. A deer or pig weakens and dies after a few days, and the monitor lizard finds the victim by smell.

The ring-tailed monitor lizard (Varanus acanthurus) is distinguished by its bright spotted color.

Monitor lizards breed once a year. The breeding season may vary depending on where the monitor lizard lives; in the tropics it coincides with the beginning of the rainy season. Monitor lizards lay from 7 to 60 eggs in burrows, hollows, anthills and termite mounds. The size of the eggs varies from 2 cm in small species to 10 cm in length in the Komodo dragon (such an egg weighs 200 g). The eggs are covered with a soft parchment shell, the incubation period is unusually long - 9-10 months! Parents do not take care of their offspring; young monitor lizards are completely independent after hatching. Medium-sized species (for example, gray monitor lizards) reach sexual maturity by 3 years.

Due to their large size, monitor lizards have few enemies. Small species and young individuals are the most vulnerable; they can even suffer from their own relatives; cases of cannibalism are known among these reptiles. Monitor lizards can be attacked by large snakes, birds of prey, and crocodiles. In defense, these animals hit the attacker with their tail, hiss, open their mouths and bite painfully.

The Salvador monitor lizard (Varanus salvadorii) is called crocodile by the British because of the similarity of this large lizard with crocodiles.

Monitor lizards also suffer greatly from hunting. In some places they are hunted for meat and eggs collected. But most often monitor lizards are killed for their skin. The skin of these animals is strong, with beautiful design and pleasant texture, it is considered an expensive raw material and is used to make exclusive shoes, bags and other accessories. Now some species of monitor lizards are listed in the national Red Data Books (gray monitor lizard), and the Komodo monitor lizard is included in the International Red Book. These reptiles pose no danger to humans. As an exception, there are a few known cases of Komodo dragons attacking people, but these can be explained by the small size of the victim (most of the victims were teenagers). Obviously, monitor lizards confuse a short person with their usual prey. Now a reserve has been organized to protect Komodo dragons, tourist access to the habitats of these animals is limited and accidents have become a thing of the past. In captivity, most large species of monitor lizards do not take root well, so they are rarely seen in zoos.

In December 1910, the Dutch administration on the island of Java received information from the administrator of the island of Flores (for civil affairs), Stein van Hensbrouck, that there were no people living on the outlying islands of the Lesser Sunda archipelago. known to science giant creatures.

Van Stein's report stated that in the vicinity of Labuan Badi on Flores Island, as well as on nearby Komodo Island, there lives an animal that the local natives call "buaya-darat", which means "earth crocodile".

Komodo dragons are one of the species potentially dangerous to humans, although they are less dangerous than crocodiles or sharks and do not pose a direct danger to adults.

According to local residents, the length of some monsters reaches seven meters, and three- and four-meter buaya-darats are common. The curator of the Butsnzorg Zoological Museum at the Botanical Park of West Java Province, Peter Owen, immediately entered into correspondence with the manager of the island and asked him to organize an expedition in order to obtain a reptile unknown to European science.

This was done, although the first lizard caught was only 2 meters 20 centimeters long. Hensbroek sent her skin and photographs to Owens. In the accompanying note, he said that he would try to catch a larger specimen, although this would not be easy, since the natives were terrified of these monsters. Convinced that the giant reptile was not a myth, the zoological museum sent an animal capture specialist to Flores. As a result, the staff of the zoological museum managed to obtain four specimens of “earthen crocodiles,” two of which were almost three meters long.

Giant monitor lizards are cannibals, and adults, on occasion, will not miss the opportunity to feast on their smaller relatives.

In 1912, Peter Owen published an article in the Bulletin of the Botanical Garden about the existence of a new species of reptile, naming a previously unknown spider animal Komodo dragon (Varanus komodoensis Ouwens). It later turned out that giant monitor lizards are found not only on Komodo, but also on the small islands of Rytya and Padar, lying to the west of Flores. A careful study of the archives of the Sultanate showed that this animal was mentioned in the archives dating back to 1840.

First World War forced to stop research, and only 12 years later interest in the Komodo dragon resumed. Now the main researchers of the giant reptile are US zoologists. On English language this reptile became known as komodo dragon(comodo dragon). The expedition of Douglas Barden managed to catch a living specimen for the first time in 1926. In addition to two living specimens, Barden also brought 12 stuffed animals to the United States, three of which are on display at the American Museum. natural history in NYC.

RESERVED ISLANDS
Indonesian National Park Komodo National Park), protected by UNESCO, founded in 1980 and includes a group of islands with adjacent warm waters and coral reefs with an area of more than 170 thousand hectares.
The islands of Komodo and Rinca are the largest in the reserve. Of course, the main celebrity of the park is the Komodo dragon. However, many tourists come here to see the unique terrestrial and underwater flora and fauna of Komodo. There are about 100 species of fish here. There are about 260 species of reef corals and 70 species of sponges in the sea.
The national park is also home to animals such as the maned sambar, Asian water buffalo, wild boar, and cynomolgus macaque.

It was Barden who established true dimensions these animals and refuted the myth of seven-meter giants. It turned out that males rarely exceed a length of three meters, and females are much smaller, their length is no more than two meters.

One bite is enough

Many years of research have made it possible to thoroughly study the habits and lifestyle of giant reptiles. It turned out that Komodo dragons, like other cold-blooded animals, are active only from 6 to 10 am and from 3 to 5 pm. They prefer dry, well-sunny areas, and are usually associated with arid plains, savannas and dry tropical forests.

In the hot season (May - October) they often stick to dry river beds with jungle-covered banks. Young animals can climb well and spend a lot of time in trees, where they find food, and in addition, they hide from their adult relatives. Giant monitor lizards are cannibals, and adults, on occasion, will not miss the opportunity to feast on their smaller relatives. As shelter from heat and cold, monitor lizards use burrows 1-5 m long, which they dig with strong paws with long, curved and sharp claws. Tree hollows often serve as shelters for young monitor lizards.

Komodo dragons, despite their size and external clumsiness, are good runners. Over short distances, reptiles can reach speeds of up to 20 kilometers, and over long distances their speed is 10 km/h. To reach food at a height (for example, on a tree), monitor lizards can stand on their hind legs, using their tail as a support. Reptiles have good hearing and sharp eyesight, but their most important sense organ is smell. These reptiles are able to smell carrion or blood at a distance of even 11 kilometers.

Most of the monitor lizard population lives in the western and northern parts of the Flores Islands - about 2000 specimens. On Komodo and Rinca there are approximately 1000 each, and on the smallest islands of the group, Gili Motang and Nusa Koda, there are only 100 individuals.

At the same time, it was noticed that the number of monitor lizards has fallen and individuals are gradually becoming smaller. They say that the decline in the number of wild ungulates on the islands due to poaching is to blame, so monitor lizards are forced to switch to smaller food.

In the photo m A young Komodo dragon near the carcass of an Asian water buffalo. The power of the jaws of monitor lizards is fantastic. Without effort, they open the victim's chest, cutting through the ribs like a huge can opener.

GAD BROTHERHOOD
From modern species Only the Komodo dragon and the crocodile monitor attack prey significantly larger than itself. The crocodile monitor's teeth are very long and almost straight. This is an evolutionary adaptation for successful bird feeding (breaking through dense plumage). They also have serrated edges, and the teeth of the upper and lower jaws can act like scissors, making it easier for them to dismember prey in the tree where they spend most of their lives.

Venomtooths are poisonous lizards. Today there are two known types of them - the gila monster and the escorpion. They live primarily in the southwestern United States and Mexico in rocky foothills, semi-deserts and deserts. Toothworts are most active in the spring, when their favorite food, bird eggs, appears. They also feed on insects small lizards and snakes. The poison is produced by the submandibular and sublingual salivary glands and travels through the ducts to the teeth of the lower jaw. When biting, the teeth of the poisonous teeth - long and curved back - enter the body of the victim almost half a centimeter.

The menu of monitor lizards includes a wide variety of animals. They practically eat everything: large insects and their larvae, crabs and storm-washed fish, rodents. And although monitor lizards are born scavengers, they are also active hunters, and often large animals become their prey: wild boars, deer, dogs, domestic and feral goats, and even the largest ungulates of these islands - Asian water buffalos.
Giant monitor lizards do not actively pursue their prey, but more often hide it and grab it when it approaches at close range.

When hunting large animals, reptiles use very intelligent tactics. Adult monitor lizards, emerging from the forest, slowly move towards grazing animals, stopping from time to time and crouching to the ground if they feel that they are attracting their attention. They can knock down wild boars and deer with a blow of their tail, but more often they use their teeth - inflicting a single bite on the animal’s leg. This is where success lies. After all, now “ biological weapons» Komodo dragon.

Reptiles have good hearing and sharp eyesight, but their most important sense organ is smell.

It has long been believed that the prey is ultimately killed by pathogens found in the monitor lizard's saliva. But in 2009, scientists found that in addition to the “deadly cocktail” of pathogenic bacteria and viruses found in saliva, to which monitor lizards themselves have immunity, reptiles are poisonous.

The Komodo dragon has two venom glands in its lower jaw that produce toxic proteins. When these proteins enter the victim's body, they prevent blood clotting, lower blood pressure, promote muscle paralysis and the development of hypothermia. The whole thing leads the victim to shock or loss of consciousness. The venom gland of Komodo dragons is more primitive than that of poisonous snakes. The gland is located on the lower jaw under the salivary glands, its ducts open at the base of the teeth, and do not exit through special channels in the poisonous teeth, like in snakes.

IN oral cavity poison and saliva mix with decaying food debris, forming a mixture in which many different deadly bacteria multiply. But this is not what surprised scientists, but the poison delivery system. It turned out to be the most complex of all similar systems in reptiles. Instead of injecting it with one blow with its teeth, like poisonous snakes, monitor lizards have to literally rub it into the wound of the victim, making jerks with their jaws. This evolutionary invention has helped giant monitor lizards survive for thousands of years.

After a successful attack, time begins to work for the reptile, and the hunter is left to follow the heels of the victim all the time. The wound does not heal, the animal becomes weaker every day. After two weeks, even such a large animal as a buffalo has no strength left, its legs give way and it falls. It's time for a feast for the monitor lizard. He slowly approaches the victim and rushes at him. His relatives come running to the smell of blood. In feeding areas, fights often occur between males of equal value. As a rule, they are cruel, but not deadly, as evidenced by the numerous scars on their bodies.

Who is next?

For humans, a huge head covered like a shell, with unkind, unblinking eyes, a toothy gaping mouth, from which protrudes a forked tongue, constantly in motion, a lumpy and folded body of a dark brown color on strong splayed paws with long claws and a massive tail. is the living embodiment of the image of extinct monsters of distant eras. One can only be amazed how such creatures could survive today practically unchanged.

The only known representative of large reptiles is Megalania prisca sizes from 5 to 7 m and weight 650-700 kg

Paleontologists believe that 5-10 million years ago, the ancestors of the Komodo dragon appeared in Australia. This assumption fits well with the fact that the only known representative of large reptiles is Megalania prisca measuring from 5 to 7 m and weighing 650-700 kg was found on this continent. Megalania, and the full name of the monstrous reptile can be translated from Latin language, as a “great ancient vagabond,” preferred, like the Komodo dragon, to settle in grassy savannas and sparse forests, where he hunted mammals, including very large ones, such as diprodonts, various reptiles and birds. These were the largest poisonous creatures that ever existed on Earth.

Fortunately, these animals became extinct, but their place was taken by the Komodo dragon, and now it is these reptiles that attract thousands of people to come to the islands forgotten by time to see natural conditions the last representatives of the ancient world.

Indonesia has 17,504 islands, although these numbers are not definitive. The Indonesian government has set itself the difficult task of conducting a complete audit of all Indonesian islands without exception. And who knows, maybe after its completion there will still be open known to people animals, although not as dangerous as Komodo dragons, but certainly no less amazing!

International scientific name

Varanus komodoensis Ouwens,

Area

Security status

Taxonomy
on Wikispecies

Images
on Wikimedia Commons

ITIS
NCBI
EOL

Lifestyle

Komodo dragons lead a solitary lifestyle, uniting in variable groups during feeding and during the breeding season.

The Komodo dragon prefers dry, well-warmed areas, and, as a rule, lives on arid plains, savannas and dry tropical forests, at low altitudes. In the hot season (May-October) it sticks to dry river beds with jungle-covered banks. Often comes to the coast in search of carrion washed ashore. Willingly enters sea water, swims well and can even swim to the neighboring island, covering a considerable distance.

When running over short distances, the monitor lizard can reach speeds of up to 20 km/h. To reach food located at a height (for example, on a tree), it can stand on its hind legs, using its tail as a support. Young animals climb well and spend a lot of time in trees.

As shelters, monitor lizards use holes 1-5 m long, which they dig with the help of strong paws with long, curved and sharp claws. Tree hollows serve as a refuge for young monitor lizards.

IN wildlife Adults have no natural enemies. Young monitor lizards are eaten by snakes, civets and birds of prey.

The natural lifespan of monitor lizards in the wild is probably around 50 years. In captivity, there have not yet been any cases of the Komodo dragon living more than 25 years.

Nutrition

Young Komodo dragon near the carcass of an Asian water buffalo

Monitor lizards feed on a wide variety of animals - both vertebrates and invertebrates. They may eat insects (mostly Orthoptera), crabs, fish, sea turtles, lizards, snakes, birds, mice and rats, civet cats, deer, wild boar, feral dogs, goats, buffalo and horses.

Cannibalism is common among Komodo dragons, especially in hungry years: adult individuals often eat young and smaller monitor lizards.

On the islands where Komodo dragons live, there are no predators larger than them, so adult dragons are at the top of the food chain. They hunt relatively large prey from ambush, sometimes knocking the victim down with blows from their powerful tail, often breaking the victim's legs in the process. Large adult Komodo dragons feed mainly on carrion, but they often receive this carrion in an unusual way. So, having tracked a deer, wild boar or buffalo in the bushes, the monitor lizard attacks and seeks to inflict a lacerated wound on the animal, into which poison and many bacteria from the monitor lizard’s oral cavity are introduced. Even the largest male monitor lizards do not have enough strength to immediately defeat a large ungulate animal, but as a result of such an attack, the victim’s wound becomes inflamed, blood poisoning occurs, the animal gradually weakens and after a while dies. The only thing left for the monitor lizards is to follow the victim until it dies. The time it takes for it to die varies depending on its size. In a buffalo, death occurs after 3 weeks. Monitor lizards have a good sense of smell and find corpses by smell using their long forked tongue. Monitor lizards from all over the island come running to the smell of carrion. In feeding areas, fights between males are frequent in order to establish and maintain a hierarchical order (usually non-lethal, although scars and traces of wounds are noticeable).

The Komodo dragon can swallow very large prey or large pieces of food, which is facilitated by the movable joint of the lower jaw bones and a capacious extensible stomach.

Females and juveniles hunt smaller animals. Cubs can even stand on their hind legs to reach small animals that are too high for adult relatives.

Currently, due to a sharp decline in the number of large wild ungulates on the islands due to poaching, even adult male monitor lizards are forced to switch to smaller prey. Because of this, the average size of monitor lizards is gradually decreasing and is now about 75% of the average size of a mature individual 10 years ago. Hunger sometimes causes the death of monitor lizards.

Reproduction

Animals of this species reach sexual maturity approximately in the tenth year of life, to which only a small part of the born monitor lizards survive. The population sex ratio is approximately 3.4:1 in favor of males. Perhaps this is a mechanism for regulating the number of the species in island habitat conditions. Since the number of females is much smaller than the number of males, during the breeding season ritual fights for the female occur between males. At the same time, monitor lizards stand on their hind legs and, clasping their opponent with their forelimbs, try to knock him down. In such fights, mature mature individuals usually win, young animals and very old males retreat. The winning male pins his opponent to the ground and scratches him with his claws for some time, after which the loser leaves.

Male Komodo dragons are much larger and more powerful than females. During mating, the male twitches his head, rubs his lower jaw against her neck and scratches the female's back and tail with his claws.

Mating occurs in winter, during the dry season. After mating, the female searches for a place to lay eggs. They are often nests of weedy chickens that build compost heaps - natural incubators from fallen leaves for thermoregulation of the development of their eggs. Having found a heap, the female monitor lizard digs a deep hole in it, and often several, in order to divert the attention of wild boars and other predators eating the eggs. Egg laying occurs in July-August, the average clutch size of the Komodo dragon is about 20 eggs. The eggs reach a length of 10 cm and a diameter of 6 cm, weighing up to 200 g. The female guards the nest for 8-8.5 months until the cubs hatch. Young lizards appear in April-May. Having been born, they leave their mother and immediately climb the neighboring trees. To avoid potentially dangerous encounters with adult monitor lizards, young monitor lizards spend the first two years of their lives in treetops, where they are inaccessible to adults.

Parthenogenesis has been found in Komodo dragons. In the absence of males, the female may lay unfertilized eggs, as observed in the Chester and London Zoos in England. Since male monitor lizards have two identical chromosomes, and females, on the contrary, are different, and the combination of identical ones is viable, all cubs will be male. Each egg laid contains either a W or a Z chromosome (in Komodo dragons, ZZ is male and WZ is female), then gene duplication occurs. The resulting diploid cells with two W chromosomes die, and with two Z chromosomes they develop into new lizards. The ability for sexual and asexual reproduction in these reptiles is probably associated with the isolation of their habitat - this allows them to found new colonies if, as a result of a storm, females without males are thrown onto neighboring islands.

I

Traditionally, it was believed that the consequences of Komodo dragon bites (serious inflammation at the site of the bite, sepsis, etc.) are caused by bacteria living in the mouth of the monitor lizard. Auffenberg pointed out the presence of pathogenic microflora in the saliva of the Komodo dragon, including Escherichia coli, Staphylococcus sp., Providencia sp., Proteus morgani And Proteus mirabilis. It was suggested that the bacteria enter the body of the lizards when feeding on carrion, as well as when sharing food with other monitor lizards. But in oral samples taken from fresh-fed zoo monitor lizards, scientists at the University of Texas found 57 different strains of bacteria found in wild monitor lizards, including Pasteurella multocida. Besides, Pasteurella multocida from monitor lizard saliva demonstrated much more intensive growth on nutrient media than that obtained from other sources.

However, recently Australian scientists working with related species of monitor lizards have determined that at least some species of monitor lizards are themselves poisonous. In late 2005, a group of scientists from the University of Melbourne suggested that big monitor lizard (Varanus giganteus), other species of monitor lizards, as well as agamas, may have toxic saliva, and that the consequences of the bites of these lizards were caused by mild intoxication. Studies have shown the toxic effects of the saliva of several species of monitor lizards (particularly the mottled monitor lizard ( Varanus varius) And Varanus scalaris), as well as some agama lizards - in particular, the bearded dragon ( Pogona barbata). Prior to this study, there was conflicting evidence regarding the toxic effect of the saliva of some monitor lizards, such as the gray monitor lizard ( Varanus griseus).

In 2009, the same researchers published further evidence that Komodo dragons have poisonous bite. An MRI scan showed the presence of two poisonous glands in the lower jaw. They removed one of these glands from a terminally ill monitor lizard at the Singapore Zoo and found that it secreted a venom containing various toxic proteins. The functions of these proteins include inhibition of blood clotting, lowering blood pressure, muscle paralysis and the development of hypothermia, leading to shock and loss of consciousness in the bitten victim.

Some scientists have proposed a hypothetical unranked group to unite snakes, monitor lizards, serpentines, spindles and iguanas Toxicofera. The unification is based on the presence of toxic components in saliva and assumes the presence of one ancestor for all “poisonous” groups (which is not indisputable).

The venom gland of monitor lizards is more primitive than that of poisonous snakes. The gland is located on the lower jaw directly under the salivary glands, its ducts open at the base of the teeth, and do not exit through special channels in the poisonous teeth, like in snakes. In the oral cavity, poison and saliva mix with decaying food debris, forming a mixture in which many different bacteria multiply.

Danger to humans

Komodo dragons are one of the species potentially dangerous to humans, although they are less dangerous than crocodiles or sharks and do not pose a direct danger to adults. Nevertheless, there are several known cases of monitor lizards attacking people, when the monitor lizards, due to some smell, mistook a person for food familiar to the monitor lizard (carrion, birds, etc.). Komodo dragon bites are extremely dangerous. After being bitten, you should consult a doctor immediately. The number of deaths due to untimely provision of medical care (and, as a result, blood poisoning) reaches 99%. Children are especially vulnerable. Monitor lizards may well kill a child under 10 years of age or cause serious injury. There are documented cases of children dying from monitor lizard attacks. Human settlements on the islands are few, but they exist and their population is growing rapidly (800 people according to 2008 data). As a rule, these are poor, fishing villages. In hungry years, especially during drought, monitor lizards come close to settlements. Their smell is especially attractive human excrement, fish, etc. Cases of monitor lizards digging up human corpses from shallow graves are well known. Recently, however, Muslim Indonesians living on the islands bury their dead, covering them with dense cast cement slabs, inaccessible to monitor lizards. Gamekeepers usually catch individuals and move them to other areas of the island. Killing monitor lizards is prohibited by law.

Since adult monitor lizards have a very good sense of smell, they can locate the source of the smell of blood up to 5 km away. There have been several documented cases of Komodo dragons attempting to attack tourists with minor open wounds or scratches. A similar danger threatens women who visit the islands where Komodo dragons live while in their menstrual cycle. Tourists are usually warned by rangers about potential danger; all groups of tourists are usually accompanied by rangers, armed with long poles with a forked end for defense against possible attacks.

Komodo dragon on an Indonesian coin

Security status

The Komodo dragon is a narrow-ranging species that is endangered due to economic activity person. Listed in the IUCN Red List and Appendix I of the Convention on International Trade in Species CITES. In 1980, Komodo National Park was established to protect the species from extinction, and excursion, environmental and adventure tours are now regularly organized.

Notes

Ananyeva N. B., Borkin L. Ya., Darevsky I. S., Orlov N. L. Five-language dictionary of animal names. Amphibians and reptiles. Latin, Russian, English, German, French. / under the general editorship of academician. V. E. Sokolova. - M.: Rus. lang., 1988. - P. 269. - 10,500 copies. - ISBN 5-200-00232-X
A. G. Bannikov, I. S. Darevsky, M. N. Denisova Life of animals. Amphibians. Reptiles / ed. V. E. Sokolova. - 2nd ed. - M.: Education, 1985. - T. 5. - P. 245. - 300,000 copies.
Ciofi, Claudia The Komodo Dragon (English) . Scientific American (March 1999). Archived
Dragon's Paradise Lost: Palaeobiogeography, Evolution and Extinction of the Largest-Ever Terrestrial Lizards (Varanidae). ploson. Archived from the original on February 21, 2012. Retrieved March 6, 2011.
Komodo dragons have proven to be poisonous. Living water. Archived from the original on February 21, 2012. Retrieved March 6, 2011.
BBC Life. Reptiles and amphibians. seasonvar (2009). Archived from the original on August 25, 2011. Retrieved March 6, 2011.

September 17th, 2015

In December 1910, the Dutch administration on the island of Java received information from the governor of the island of Flores (for civil affairs), Stein van Hensbrouck, that giant creatures unknown to science lived on the outlying islands of the Lesser Sunda archipelago.

Of course, you already guessed who we’re talking about now...

According to local residents, some monsters reach seven meters in length, and three- and four-meter buaya darats are common. The curator of the Butsnzorg Zoological Museum at the Botanical Park of West Java Province, Peter Owen, immediately entered into correspondence with the manager of the island and asked him to organize an expedition in order to obtain a reptile unknown to European science.

In 1912, Peter Owen published an article in the Bulletin of the Botanical Garden about the existence of a new species of reptile, naming the previously unknown animal the Komodo dragon (Varanus komodoensis Ouwens). It later turned out that giant monitor lizards are found not only on Komodo, but also on the small islands of Rytya and Padar, lying to the west of Flores. A careful study of the archives of the Sultanate showed that this animal was mentioned in the archives dating back to 1840.

The First World War forced a halt to research, and only 12 years later did interest in the Komodo dragon resume. Now the main researchers of the giant reptile are US zoologists. In English, this reptile became known as the Komodo dragon. The expedition of Douglas Barden managed to catch a living specimen for the first time in 1926. In addition to two living specimens, Barden also brought 12 stuffed specimens to the United States, three of which are on display at the American Museum of Natural History in New York.

Indonesian Komodo National Park, protected by UNESCO, was founded in 1980 and includes a group of islands with adjacent warm waters and coral reefs covering an area of more than 170 thousand hectares.
The islands of Komodo and Rinca are the largest in the reserve. Of course, the main celebrity of the park is the Komodo dragon. However, many tourists come here to see the unique terrestrial and underwater flora and fauna of Komodo. There are about 100 species of fish here. There are about 260 species of reef corals and 70 species of sponges in the sea.
The national park is also home to animals such as the maned sambar, Asian water buffalo, wild boar, and cynomolgus macaque.

It was Barden who established the true size of these animals and refuted the myth of seven-meter giants. It turned out that males rarely exceed a length of three meters, and females are much smaller, their length is no more than two meters.

Of the modern species, only the Komodo dragon and the crocodile monitor attack prey significantly larger than themselves. The crocodile monitor's teeth are very long and almost straight. This is an evolutionary adaptation for successful bird feeding (breaking through dense plumage). They also have serrated edges, and the teeth of the upper and lower jaws can act like scissors, making it easier for them to dismember prey in the tree where they spend most of their lives.

Venomtooths are poisonous lizards. Today there are two known types of them - the gila monster and the escorpion. They live primarily in the southwestern United States and Mexico in rocky foothills, semi-deserts and deserts. Toothworts are most active in the spring, when their favorite food—bird eggs—appears. They also feed on insects, small lizards and snakes. The poison is produced by the submandibular and sublingual salivary glands and travels through the ducts to the teeth of the lower jaw. When biting, the teeth of the poisonous teeth - long and curved back - enter the body of the victim almost half a centimeter.

The menu of monitor lizards includes a wide variety of animals. They eat practically everything: large insects and their larvae, crabs and storm-washed fish, rodents. And although monitor lizards are born scavengers, they are also active hunters, and often large animals become their prey: wild boars, deer, dogs, domestic and feral goats, and even the largest ungulates of these islands - Asian water buffalos.
Giant monitor lizards do not actively pursue their prey, but more often hide it and grab it when it approaches at close range.

Research led by Bryan Fry from the University of Queensland (Australia) has shown that in terms of the number and types of bacteria typically found in the mouth of the Komodo dragon, it is not fundamentally different from other carnivores.

Moreover, as Fry states, the Komodo dragon is a very clean animal.

Komodo dragons, which inhabit the islands of Indonesia, are the most large predators on these islands. They hunt pigs, deer and Asian buffalo. 75% of pigs and deer die from the bite of a monitor lizard within 30 minutes from loss of blood, another 15% - after 3-4 hours from the poison secreted by its salivary glands.

A larger animal, a buffalo, when attacked by a monitor lizard, always, despite deep wounds, leaves the predator alive. Following his instinct, the bitten buffalo usually seeks refuge in a warm pond, the water of which is teeming with anaerobic bacteria, and eventually succumbs to infection that penetrates into its legs through the wounds.

Pathogenic bacteria found in the oral cavity of the Komodo dragon in previous studies, according to Fry, are traces of infections entering its body from an infected drinking water. The amount of these bacteria is not enough to cause the death of a buffalo from a bite.

In the oral cavity, poison and saliva mix with decaying food debris, forming a mixture in which many different deadly bacteria multiply. But this is not what surprised scientists, but the poison delivery system. It turned out to be the most complex of all similar systems in reptiles. Instead of injecting it with one blow with its teeth, like poisonous snakes, monitor lizards have to literally rub it into the wound of the victim, making jerks with their jaws. This evolutionary invention has helped giant monitor lizards survive for thousands of years.

Paleontologists believe that 5-10 million years ago, the ancestors of the Komodo dragon appeared in Australia. This assumption fits well with the fact that the only known representative of large reptiles - Megalania prisca, measuring from 5 to 7 m and weighing 650-700 kg, was found on this continent. Megalania, and the full name of the monstrous reptile can be translated from Latin as “great ancient tramp”, preferred, like the Komodo dragon, to settle in grassy savannas and sparse forests, where he hunted mammals, including very large ones, such as diprodonts, various reptiles and birds. These were the largest poisonous creatures that ever existed on Earth.

Fortunately, these animals became extinct, but their place was taken by the Komodo dragon, and now it is these reptiles that attract thousands of people to come to the islands forgotten by time to see the last representatives of the ancient world in natural conditions.

Indonesia has 17,504 islands, although these numbers are not definitive. The Indonesian government has set itself the difficult task of conducting a complete audit of all Indonesian islands without exception. And who knows, maybe at the end of it, animals unknown to people will still be discovered, perhaps not as dangerous as Komodo dragons, but certainly no less amazing!

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