KOMODO DRAGON

The Komodo dragon (Varanus komodoensis) is a species of lizard that inhabits the islands of Komodo, Rinca, Flores, and Gili Motang. 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 discovered 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.

Venom and bacteria
A sleeping Komodo dragon. Notice the large, curved claws used in fighting and eating.In late 2005, University of Melbourne researchers concluded that the perentie (Varanus giganteus), other species of monitor, and agamids may be somewhat venomous. The research team showed that the immediate effects of bites from these lizards were caused by mild envenomation. Bites on human digits by a lace monitor (V. varius), a Komodo dragon, and a spotted tree monitor (V. scalaris) were observed, and all produced similar results in humans: rapid swelling within minutes, localized disruption of blood clotting, shooting pain up to the elbow, with some symptoms lasting for several hours. It has been proposed that all venomous lizards, together with their nonvenomous relatives and all snakes, share a common venomous ancestor.

Komodo dragons also possess virulent bacteria in their saliva, of which more than 28 Gram-negative and 29 Gram-positive strains have been isolated. These bacteria cause septicemia in their victim; if an initial bite does not kill the prey animal and it escapes, it will commonly succumb within a week to the resulting infection. The most harmful bacterium in Komodo dragon saliva appears to be a deadly strain of Pasteurella multocida, from studies performed with laboratory mice. There is no specific antidote to the bite of a Komodo dragon, but it can usually be treated by sterilizing the wounded area and giving the patient large doses of antibiotics. If not treated promptly, gangrene can quickly develop around the bite, which may require amputation of the affected area. Because the Komodo dragon appears immune to its own microbes, much research has been done searching for the antibacterial molecule(s) in the hopes of human medicinal use.