Komodo dragon

The Komodo dragon (Varanus komodoensis) is a venomous species of lizard that inhabits the islands of Komodo, Rinca, Flores, and Gili Motang in Indonesia.A member of the monitor lizard family (Varanidae), it is the largest living species of lizard, growing to an average length of 2 to 3 metres (6.6 to 9.8 ft) and weighing around 70 kilograms (150 lb). Their unusual size is attributed to island gigantism, since there are no other carnivorous animals to fill the niche on the islands where they live, and also to the Komodo dragon's low metabolic rate.As a result of their size, these lizards dominate the ecosystems in which they live.Although Komodo dragons eat mostly carrion, they will also hunt and ambush prey including invertebrates, birds, and mammals.

Mating begins between May and August, and the eggs are laid in September. About twenty eggs are deposited in abandoned megapode nests and incubated for seven to eight months, hatching in April, when insects are most plentiful. Young Komodo dragons are vulnerable and therefore dwell in trees, safe from predators and cannibalistic adults. They take around three to five years to mature, and may live as long as fifty years. They are among the rare vertebrates capable of parthenogenesis, in which females may lay viable eggs if males are absent.

Komodo dragons were first recorded by Western scientists in 1910. Their large size and fearsome reputation make them popular zoo exhibits. In the wild their range has contracted due to human activities and they are listed as vulnerable by the IUCN. They are protected under Indonesian law, and a national park, Komodo National Park, was founded to aid protection efforts

Etymology
The Komodo dragon is also known as the Komodo monitor or the Komodo Island monitor in scientific literature, although this is not very common. To the natives of Komodo Island, it is referred to as ora, buaya darat (land crocodile) or biawak raksasa (giant monitor).

Evolutionary history
The evolutionary development of the Komodo dragon started with the Varanus genus, which originated in Asia about 40 million years ago and migrated to Australia. Around 15 million years ago, a collision between Australia and Southeast Asia allowed the varanids to move into what is now the Indonesian archipelago. The Komodo dragon is believed to have differentiated from its Australian ancestors 4 million years ago, extending their range to as far east as the island of Timor. Dramatic lowering of sea level during the last glacial period uncovered extensive stretches of continental shelf that the Komodo dragon colonized, becoming isolated in their present island range as sea levels rose afterwards.

Description

Closeup of a Komodo dragon's skin
In the wild, an adult Komodo dragon usually weighs around 70 kilograms (150 lb),although captive specimens often weigh more. The largest verified wild specimen was 3.13 metres (10.3 ft) long and weighed 166 kilograms (370 lb), including undigested food.The Komodo dragon has a tail as long as its body, as well as about 60 frequently replaced serrated teeth that can measure up to 2.5 centimeters (1 inch) in length. Its saliva is frequently blood-tinged, because its teeth are almost completely covered by gingival tissue that is naturally lacerated during feeding. This creates an ideal culture for the virulent bacteria that live in its mouth. It also has a long, yellow, deeply forked tongue.

Senses
The Komodo dragon does not have a particularly acute sense of hearing, despite its visible earholes, and is only able to hear sounds between 400 and 2000 hertz It is able to see as far away as 300 metres (980 ft), but because its retinas only contain cones, it is thought to have poor night vision. The Komodo dragon is able to see in colour, but has poor visual discrimination of stationary objects


The Komodo dragon does not have a particularly acute sense of hearing, despite its visible earholes, and is only able to hear sounds between 400 and 2000 hertz.It is able to see as far away as 300 metres (980 ft), but because its retinas only contain cones, it is thought to have poor night vision. The Komodo dragon is able to see in colour, but has poor visual discrimination of stationary objects.

A young Komodo dragon photographed on Rinca feeding on a water buffalo carcass
The largest animals generally eat first, while the smaller ones follow a hierarchy. The largest male asserts his dominance and the smaller males show their submission by use of body language and rumbling hisses. Dragons of equal size may resort to “wrestling”. Losers usually retreat though they have been known to be killed and eaten by victors.

The Komodo dragon's diet is wide-ranging, and includes invertebrates, other reptiles (including smaller Komodo dragons), birds, bird eggs, small mammals, monkeys, wild boar, goats, deer, horses, and water buffalo.Young Komodos will eat insects, eggs, geckos, and small mammals.Occasionally they consume humans and human corpses, digging up bodies from shallow graves. This habit of raiding graves caused the villagers of Komodo to move their graves from sandy to clay ground and pile rocks on top of them to deter the lizards.The Komodo dragon may have evolved to feed on the extinct dwarf elephant Stegodon that once lived on Flores according to evolutionary biologist Jared Diamond. The Komodo dragon has also been observed intentionally startling a pregnant deer in the hopes of a miscarriage whose remains they can eat, a technique that has also been observed in large African predators.

Because the Komodo dragon does not have a diaphragm, it cannot suck water when drinking, nor can it lap water with its tongue. Instead, it drinks by taking a mouthful of water, lifting its head, and letting the water run down its throat.

Venom

Komodo dragon coin, issued by Indonesia
Komodo dragons were first documented by Europeans in 1910, when rumors of a "land crocodile" reached Lieutenant van Steyn van Hensbroek of the Dutch colonial administration.Widespread notoriety came after 1912, when Peter Ouwens, the director of the Zoological Museum at Bogor, Java, published a paper on the topic after receiving a photo and a skin from the lieutenant, as well as two other specimens from a collector. Later, the Komodo dragon was the driving factor for an expedition to Komodo Island by W. Douglas Burden in 1926. After returning with 12 preserved specimens and 2 live ones, this expedition provided the inspiration for the 1933 movie King Kong. It was also Burden who coined the common name "Komodo dragon." Three of his specimens were stuffed and are still on display in the American Museum of Natural History.

[ Studies
The Dutch, realizing the limited number of individuals in the wild, outlawed sport hunting and heavily limited the number of individuals taken for scientific study. Collecting expeditions ground to a halt with the occurrence of World War II, not resuming until the 1950s and 1960s, when studies examined the Komodo dragon's feeding behavior, reproduction, and body temperature. At around this time, an expedition was planned in which a long-term study of the Komodo dragon would be undertaken. This task was given to the Auffenberg family, who stayed on Komodo Island for 11 months in 1969. During their stay, Walter Auffenberg and his assistant Putra Sastrawan captured and tagged more than 50 Komodo dragons. The research from the Auffenberg expedition would prove to be enormously influential in raising Komodo dragons in captivity.Research after the Auffenberg family has shed more light on the nature of the Komodo dragon, with biologists such as Claudio Ciofi continuing to study the creatures.


Danger to humans
Although attacks are very rare, Komodo dragons have been known to attack humans; on June 4, 2007 a Komodo dragon attacked an eight-year-old boy on Komodo Island. The boy later died of massive bleeding from his wounds. It was the first recorded fatal attack in 33 years. Natives blamed the attack on environmentalists outside the island prohibiting goat sacrifices. This denied the Komodo dragons their expected food source, causing them to wander into human civilization in search of food. A belief held by many natives of Komodo Island is that Komodo dragons are actually the reincarnation of fellow kinspeople and should thus be treated with reverence

On March 24, 2009, two Komodo Dragons attacked and killed fisherman Muhamad Anwar on Komodo. Anwar was attacked after he fell out of a sugar-apple tree and was left bleeding badly from bites to his hands, body, legs, and neck. He was taken to a clinic on the neighboring island of Flores where he was pronounced dead on arrival.
Conservation

Komodo dragons at Toronto Zoo. Komodo dragons in captivity often grow fat, especially in their tails, due to regular feeding.
Another documentation of play in Komodo dragons comes from the University of Tennessee, where a young Komodo dragon named "Kraken" interacted with plastic rings, a shoe, a bucket, and a tin can by nudging them with her snout, swiping at them, and carrying them around in her mouth. She treated all of them differently than her food, prompting leading researcher Gordon Burghardt to conclude that they disprove the view of object play being "food-motivated predatory behavior." Kraken was the first Komodo dragon hatched in captivity outside of Indonesia, born in the National Zoo on September 13, 1992

Even seemingly docile dragons may become aggressive unpredictably, especially when the animal's territory is invaded by someone unfamiliar. In June 2001, a Komodo dragon seriously injured Phil Bronstein—executive editor of the San Francisco Chronicle—when he entered its enclosure at the Los Angeles Zoo after being invited in by its keeper. Bronstein was bitten on his bare foot, as the keeper had told him to take off his white shoes, which could have potentially excited the Komodo dragon Although he escaped, he needed to have several tendons in his foot reattached surgically