Komodo dragons, or otherwise called Komodo dragons (Varanus komodoensis), are the largest species of lizards in the world living on the islands of Komodo, Rinca, Flores, Gili Motang, and Gili Dasami in Nusa Tenggara. The lizard is a native of the island of Komodo also called by the local name ora.
Including members of the Varanidae lizard family, and klad Toxicofera, komodo is the largest lizard in the world, with an average length of 2-3 m. This large size is associated with island gigantism, which is the tendency of meraksasanya body of certain animals that live on the small island associated with the absence of carnivorous mammals on the island where the life of the dragons, and the rate of small Komodo metabolism. Because of its large body, this lizard occupies the position of the top predator that dominates the ecosystem where he lives.
Her big body and terrible reputation make them popular at the zoo. The habitat of dragons in the wild has been shrinking due to human activity and hence IUCN incorporates Komodo as a species susceptible to extinction. The large lizard is now protected under Indonesian government regulations and a national park, Komodo National Park, was established to protect them.
Anatomy and morphology
In the wild, adult dragons typically weigh about 70 kilograms, but the dragons that are kept in captivity often have greater body weight. The largest ever wild specimen has a length of 3.13 meters and weighs about 166 kilograms, including the weight of undigested food in its stomach. Although the Komodo is listed as the largest living lizard, but not the longest. This reputation is held by the Papua lizard (Varanus salvadorii).
Komodo dragons have the same length of tail with their bodies, and about 60 pieces of sharp teeth along about 2.5 cm, which are often replaced. Komodo dragons are often mixed with blood because their teeth are almost entirely covered by gingival tissue and the tissue is torn during the meal. This condition creates an ideal growth environment for deadly bacteria that live in their mouths.
Komodo has a long tongue, yellow and branched. Male dragons are bigger than female dragons, with a dark gray to brick red color, while the female dragon is more olive-green, and has a small yellow cut on the throat. Younger dragons are more colorful, with yellow, green and white on a black background.
Physiology
Komodo does not have a sense of hearing, despite having ear holes. The lizard is able to see up to 300 m, but since the retina only has conical cells, it is not so good to see in the darkness of night. Komodo is able to distinguish colors but not how to distinguish objects that are not moving.
Komodo uses his tongue to detect taste and smell stimuli, like other reptiles, with the vomeronasal senses utilizing Jacobson's organs, a capability that can aid navigation in the dark. With the help of the wind and his habit of tilting his head to the right and to the left when walking, Komodo dragons can detect the presence of carrion as far as 4-9.5 kilometers. Komodo dragon nostrils are not a good olfactory tool because they do not have a body partition. This animal has no taste buds on its tongue, there are only a few nerve endings in the back of the throat.
Komodo scales, some of which are reinforced with bone, have sensors connected to nerves that facilitate touch stimulation. The scales around the ears, lips, chin and soles have three sensors of stimulation or more.
Komodo was once considered deaf when research found that whispers, increased sounds and screams did not result in agitation (disturbance) in wild Komodo dragons. It was denied later when the London ZSL Zoo employee Joan Proctor trained lizards to eat out in her voice, even when she was not seen by the lizard
Ecology, behavior and way of life
Komodo dragons are naturally found only in Indonesia, on the islands of Komodo, Flores and Rinca and several other islands in Nusa Tenggara. Komodo dragons are habitable in open open grasslands, savannas and tropical forests at low altitudes. They are active during the day, although sometimes active also at night. Komodo dragons are solitary animals, gathered together only during meals and breeding.
This large reptile can run fast up to 20 kilometers per hour at short distances; Swimming very well and able to dive as deep as 4.5 meters; As well as good at climbing trees using their powerful claws. To capture prey that is out of reach, the Komodo dragon can stand on its hind legs and use its tail as a support. With age, Komodo dragons use more claws as weapons, because their large size makes it difficult to climb trees.
For shelter, dragons dig a hole 1-3 meters wide with front legs and strong claws. Because of her large body and sleeping habits in the hole, dragons can maintain body heat during the night and reduce the time of sunbathing the next morning. Komodo usually hunt during the day until the afternoon, but stay shelter during the hottest part of the day. Hidden places Komodo dragons are usually located in the area of gumuk or hills with sea breeze, open from vegetation, and here and there scattered animal dung. This place is generally also a strategic location to ambush deer.
Behavior eating
Komodos are carnivorous animals. Although they mostly eat carcasses, research shows that they also hunt live prey by sneaking followed by a sudden attack on their victims. When the prey comes near the hiding place of the dragons, the animal immediately attacks it on the underside of the body or throat. Komodo dragons can find their prey with a keen sense of smell, which can find dead or dying animals at a distance of up to 9.5 kilometers.
This ancient reptile ate by tearing away large chunks of meat and then swallowing it roundly while its front legs held off its prey. For small to large prey to goats, it could be the meat consumed once. The contents of the prey in the form of plants are usually left untouched.
Reddish saliva and exit in large quantities greatly help dragons in swallowing their prey. However, the process of swallowing still takes a long time; 15-20 minutes is needed to swallow a goat. Komodo sometimes try to speed up the process of swallowing it by emphasizing the carcass of its prey to a tree, so that the carcass can enter through the esophagus. And sometimes the push was so hard that the tree would fall.
To avoid getting choked when swallowing, the dragon breathes through a small channel under the tongue, which is directly related to the lungs. Its jaws can be developed freely, its flexible skull, and its incredibly stretchy stomach allow the Komodo dragon to eat large prey, up to 80% of its own body weight in one meal.
After a meal, dragons run dragging his body that is satiating looking for sunshine to bask and speed up the process of digestion. Otherwise, the food can rot in his stomach and poison his own body. Due to its slow metabolism, large dragons can survive by eating only 12 times a year or about once a month.
Once the prey's meat is digested, the Komodo drags out the remnants of the horns, the hair and teeth of its prey, in clumps mixed with the foul-smelling mucus, which lumps are known as gastric pellets. After that dragons sweep his face to the ground or to the bush to clear the remnants of mucus that is still attached, the behavior that raises the notion that dragons, like humans, do not like the smell of saliva itself.
In the collection, the largest dragons usually eat first, followed by smaller ones according to the hierarchy. The largest males show their dominance through body language and hiss; Who was welcomed in the same language by other smaller males to show his confession of that power. Komodo-dragons of the same size may be fighting against powers, by means of a kind of wrestling lizards, until one of them admits defeat and retreat; Although sometimes losers can be killed in a fight and preyed on by the winner.
Komodo dragon macaques vary widely, including a variety of invertebrates, other reptiles (including smaller bodies), birds and eggs, small mammals, monkeys, wild pigs, goats, deer, horses and buffalo. Young Komodo prey on insects, eggs, lizards, and small mammals. Sometimes dragons also prey on humans and corpses dug from shallow grave holes. This habit caused the inhabitants of Komodo Island to avoid sandy soil and chose to bury the corpse in clay, and covered it with rocks to keep from being dragged.
There is also a suspect that the Komodo dragons to prey on Stegodon dwarf elephants who once lived in Flores. Komodo dragons have also been observed when shocking and frightening pregnant female deer, in the hope that the miscarriage and carcass of the fetus may be preyed, a behavior that is also found in large predators in Africa.
Because it does not have a body cavity, dragons can not breathe water or lick water for drinking (like a cat). Instead, the dragons 'snatched' the water with all its mouth, then raised its head so that water flowed into his stomach.
Poison and bacteria
At the end of 2005, researchers from the University of Melbourne, Australia, concluded that Perentie lizards (Varanus giganteus) and other lizards, as well as lizards from the Agamidae tribe, may have some kind of can. It is well known that bite wounds from these animals are highly susceptible to infection due to bacteria living in the mouths of these lizards, but these researchers show that the immediate effects that appear on the bite wounds are due to the influx of strength Medium.
These researchers have observed the wounds in the hands of humans from Varanus varius bites, V. scalaris and Komodo dragons, all showing similar reactions: swelling rapidly within minutes, localized disorders in blood clotting, gripping pain to the elbow , With some symptoms that persisted for several hours later.
A highly toxic contained gland has been successfully taken from the mouth of a dragon at the Singapore Zoo, and convinces researchers of the ingredients that the Komodo dragon can possess.
In addition to containing can, dragons saliva also has a variety of deadly bacteria in it; More than 28 Gram-negative and 29 Gram-positive bacteria have been isolated from this saliva. These bacteria cause septicemia in the victim. If the Komodo drag does not directly kill the prey and the prey can escape, generally these unlucky prey will die within a week due to infection.
The most lethal bacteria in Komodo dragons are the most deadly Pasteurella multocida bacteria; Known through experiments with laboratory mice. Because the Komodo dragon appears to be immune to its own microbial, much research has been done to look for antibacterial molecules in the hope of being used for human treatment.
Reproduction
The mating season occurs between May and August, and Komodo dragons are laid in September. During this period, the male dragons fought to defend the female and its territory by "wrestling" with other males while standing on their hind legs. The losing Komodo will fall and "locked" to the ground. Both male dragons can vomit or defecate when preparing for combat.
The winner of the battle will flick his long tongue on the female's body to see her acceptance. Female dragons are antagonistic and fight with their teeth and claws during the early phase of pairs. Furthermore, the males must fully control the females during intercourse so as not to hurt. Another behavior that is shown during this process is that males rub their chin on the female, scratching hard on their backs and licking. Copulation occurs when the males enter one hemipenisnya into the female cloaca. Komodo dragons can be monogamous and form "pairs," a rare trait for lizards.
The females will lay their eggs in the hole of the ground, scratching a cliff of hills or mounds of abandoned-footed birds' nests. Komodo prefer to keep the eggs in the nest that has been abandoned. An average Komodo dragon contains 20 eggs that will hatch after 7-8 months. The female lies on the eggs to incubate and protect it until it hatches around April, at the end of the rainy season when there are so many insects.
The hatching process is an exhausting effort for the Komodo dragon, which comes out of the eggshell after tearing it with an egg tooth that will be dated after the heavy work is done. After successfully tearing the eggshell, baby dragons can lie on their egg shells for several hours before starting digging out their nests. When hatching, these babies are less powerful and predator-prone.
Young Komodo dragons spend their first years on trees, where they are relatively safe from predators, including from the cannibalized cannibal dragons, of which about 10% of the food is young lizards that are successfully hunted. Komodo takes three to five years to become an adult, and can live more than 50 years.
In addition to the normal reproductive process, there are several examples of cases of female dragons producing children without the presence of males (parthenogenesis), a phenomenon also known to occur in some other reptile species such as Cnemidophorus.
Parthenogenesis
The river, a Komodo dragon at the London Zoo, had spawn in early 2006 after being separated from males for more than two years. Scientists initially thought that the Komodo dragon could store sperm for a long time resulting from a marriage with a male dragon in the past, an adaptation known as superfecundation.
On December 20, 2006, it was reported that Flora, a dragons living in Chester Zoo, UK is the second dragon known to produce eggs without fertilization (fertilization from marriage). He took out 11 eggs, and 7 of them managed to hatch.
Researchers from the University of Liverpool in northern Britain conducted genetic tests on three eggs that failed to hatch after being moved to an incubator, and it was evident that Flora had no physical contact with the Komodo dragons. After this surprising finding, the test was then performed on the eggs of the River and found that the eggs were produced without outside conception.
Komodo has a ZW chromosomal sex determination system, not the XY sex-determination system. The descendants of Flora are male, indicating the occurrence of several things. It is clear that the unfertilized Flora's egg is haploid at first and then doubles its own chromosomes into diploids; And that it does not produce diploid eggs, as can occur if one of the processes of meiotic fission-reduction in the ovaries fails.
When a female dragon (having a ZW sex chromosome) produces a child this way, it inherits only one of the chromosome pairs it has, including one of its two sex chromosomes. A set of single chromosomes is then duplicated in eggs, which develop partenogenetically. The egg that receives the Z chromosome will be ZZ (male); And who receive the W chromosome will become WW and fail to develop.
It is presumed that such reproductive adaptation allows a female animal to enter an isolated ecological niche (like an island) and by way of parthenogenesis then produces male offspring. Through marriage with her child at the next moment these animals can form populations that reproduce sexually, because it can produce male and female offspring. Although this adaptation is beneficial, zoos need to be vigilant because parthenogenesis may reduce genetic diversity.
On January 31, 2008, Sedgwick County Zoo in Wichita, Kansas became the first zoo to document parthenogenesis in dragons in America. The zoo has two adult female Komodo dragons, one of which produces 17 eggs on May 19-20, 2007. Only two eggs are incubated and hatched due to space availability issues; The first hatch on January 31, 2008, followed by the second on February 1st. The two children of dragons are male.
Evolution
The evolution of the Komodo dragon began with the Varanus clan, which emerged in Asia some 40 million years ago and then migrated to Australia. About 15 million years ago, the encounter of the continental plates of Australia and Southeast Asia enabled the lizards to move into what is now Indonesia. Komodo dragons are believed to have evolved from their Australian ancestors some 4 million years ago, and have expanded their territory eastward as far as Timor. Changes in sea level since the Ice Age have made Komodo dragons limited to their current distribution area.
Komodo and humans
Invention
Komodo was first documented by Europeans in 1910. Its name expanded after 1912, when Pieter Antonie Ouwens, director of the Zoological Museum in Buitenzorg (now Bogor), published a paper on dragons after receiving photographs and skins of these reptiles. Later on, the Komodo dragons were the driving force for the expedition to Komodo Island by W. Douglas Burden in 1926. After returning with 12 preserved specimens and 2 live dragons, this expedition provided inspiration for King Kong's 1933 film. W. Douglas Burden was a person The first to give the name "Komodo dragon" to this animal. Three of the specimens of the Komodo dragons that were acquired were reshaped into animal displays and are still preserved in the American Museum of Natural History.
Research
The Dutch, being aware of the declining number of these animals in the wild, prohibit the hunting of dragons and limit the number of animals taken for scientific research. The Komodo Expedition was suspended during World War II, and it was not continued until the 1950s and '60s when researches were conducted on the eating, reproduction and body temperature of dragons. In those years, another expedition was designed to research dragons in the long run. This task fell into the hands of the Auffenberg family, who then lived for 11 months on the island of Komodo in 1969. During that time, Walter Auffenberg and Son of Letters as his assistant, managed to capture and mark more than 50 Komodo dragons. The results of this expedition was very influential on the increased captivity of dragons. Subsequent studies then provide a clearer and clearer picture of the nature of the Komodo dragon, so biologists like Claudio Ciofi can continue the deeper study.
Conservation
Komodo dragons are a species prone to extinction, and are categorized as Vulnerable species on the IUCN Red List list. Approximately 4000-5000 tailed dragons are still living in the wild. This population is limited to spread on Rinca islands (1,300 birds), Gili Motang (100), Gili Dasami (100), Komodo (1,700), and Flores (probably around 2,000). However, there are concerns about this population because it is estimated that there are only 350 productive and breeding females. Starting from this concern, in 1980 the Government of Indonesia established the establishment of Komodo National Park to protect Komodo dragons and their ecosystems on several islands including Komodo, Rinca and Padar.
Later, Wae Wuul and Wolo Tado Nature Reserve on Flores Island were also established to help conserve the dragons. But on the other hand, there is evidence to suggest that Komodo dragons, at least in part, have become accustomed to human presence. Komodo dragons are accustomed to feeding carcasses of livestock, as attractions to attract tourists at several locations of visits.
Volcanic activity, earthquakes, habitat destruction, fires (Komodo dragons on Padar Island are almost extinct due to natural fires), reduced prey, increased tourism, and poaching; All contributing to the vulnerable status of the Komodo dragons. CITES (The Convention on International Trade in Endangered Species) has determined that the trading of dragons, skins, and other products of these animals is illegal.
Although rare, Komodo dragon is known to kill humans. On June 4, 2007, a Komodo dragon was known to attack an eight-year-old boy. The child later died of heavy bleeding from his wounds. This is the first record of an attack that has resulted in deaths in the past 33 years.
Captive breeding
It has been a long time since the Komodo dragons have become an exciting spectacle in many zoos, especially because of their size and reputation that make it so popular. However, these animals are rarely owned by zoos, because the Komodo dragon is susceptible to infections and diseases caused by parasites, and not easy to breed.
The first Komodo dragons were on the Smithsonian Zoo in 1934, but these animals only survived for two years. Efforts to maintain this reptile continue, but the age of these animals in the tangkaran not so long, an average of only 5 years in the zoo. Research conducted by Walter Auffenberg above, whose results are later published as the book The Behavioral Ecology of the Komodo Monitor, ultimately allows the maintenance and breeding of these endangered species in captivity.
It has been observed that many individually preserved dragons exhibit benign behavior for a period of time. Reported on many occasions, that the handlers managed to bring out the dragons from their cages to interact with visitors, including children in between, without the consequences that endanger visitors. Komodo seems to be able to recognize people one by one. Ruston Hartdegen of the Dallas Zoo reports that the preserved Komodo dragons react differently when faced with the usual handler, with other less-known handlers, or with a completely unknown handler.
Research on pet dragon proves that these animals love to play. A study of the Komodo dragon pushing the shovel left by its keepers clearly shows that the animal is attracted to the shovel-shaped sound as it shifts along the rocky surface. A young female dragon at the National Zoo in Washington, D.C. Happy to reach and shake things including statues, drink cans, plastic circles, and blankets. Komodo is also happy to enter-enter his head into the box, shoes, and various other objects. Komodo is not can not distinguish these objects with food; He just ate it when the objects were smeared with rat blood. This playful behavior can be compared with mammal playing behavior.
Another note about the fun of dragons gained from the University of Tennessee. A young Komodo dragon named "Kraken" plays with plastic bracelets, shoes, buckets and cans, by pushing it, kicking it, and carrying it with its mouth. The Kraken treats things differently from what they are feeding, prompting Gordon Burghardt-the researchers-to conclude that these animals have dismissed the view that such a game is "predator-predatory behavior".
Komodo dragons that seem benign can behave aggressively unexpectedly, especially if the territory is violated by someone who is not familiar. In June 2001, a Komodo dragon attack caused serious injuries to Phil Bronstein-the executive editor of the San Francisco Chronicle and the former husband of Sharon Stone, a famous American actress-when he entered the cage at the invitation of his handler. Bronstein was bitten by the Komodo dragon at his bare feet after the handler advised him to remove his white shoes, which he feared could provoke Komodo's attention. Although the man got away, but he needed surgery to reconnect his injured muscle tendon.
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