Varanus Komodoensis
Ouwens 1912Komodo dragon, ora.
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Although the Portuguese and Dutch had been "busy" in Indonesia since the 16th Century the Komodo dragon escaped the attention of modem science until 1910. Lieutenant Van Steyn van Hensbroek of the Dutch Infantry, who was based in Flores, mentioned to Ouwens that a particularly large monitor lizard was said to inhabit the neighbouring island of Komodo. When the Lieutenant visited the islands he heard reports that the animals grew to 6 or 7 metres long, but the largest he was able to catch was only 2.2 metres long. A collector was despatched to Komodo who returned to Java with two adults (290cm and 235cm) and two juveniles (I00cm) which were formally described in 1912. Ouwens tried to play down the stories of 6 metre long lizards, but doubtless felt obliged to report all that he had heard about the animals. Stories of the giant lizards spread very quickly and before long trophy hunters began to nock to the islands in the hope of shooting some of the massive beasts. Discounting the locals' account that the lizards rarely if ever exceeded three metres in length, the hunters haited the dragons with dead goats and must have found them very easy targets as they grouped around the carrion. Despite stories of 4 or 5 metres animals being taken (e.g. Broughton 1936). the largest that reached Europe and North America were 2.75 metres long . The myths persisted however until they were finally laid to rest by Walter Auffenberg's 13-month field study of the species which reported (1981) that the largest specimen availahle was almost exactly 3 metres long. Several other species of monitor lizard attain a similar size, but none have the bulk of the Komodo dragon. The heaviest recorded by Auffenberg was a 2.5m animal which weighed 54kg. When full of food the same animal weighed around 100kg. Auffenberg believed that 3m lizards could therefore weigh up to 250kg, and although this figure is often cited as their maximum weight there is no hard evidence to support it.
Komodo dragons inhabit areas of dry savannah and woodland. and frequent thick monsoon forest along water courses, They spend most of their time on the boundary of grassland and lorest where they have access to a wide range of temperatures within a small area, As juveniles they lead very secretive lives sheltering under bark and feeding on insects (grasshoppers and beetles) and geckoes. As they grow they become too heavy to forage on trees and their diet shifts to one comprised mainly of rodents and birds (and the occasional porcupine) which are collected on or below the ground , Adult Komodo dragons are fearsome predators. They will attack and kill weaker dragons and feed on a variety of snakes (including vipers and cobras), crocodile eggs and young and often raid the nests of megapode hirds (Lincoln 1974), But the bulk of their diet is made up of large mammals; goats, deer. pigs, horses and water buffalo. These prey are often caught by ambush or surprise, The dragons hide in long grass along game trails and rush their prey as it passes, crippling it by severing tendons in the legs before killing it with a bite to the throat or by ripping out the intestines. Auffenberg suggests that the lizards needed to get to within 1m of the prey without being detected for such ambushes to be effective. He provides pictures of a 320kg buffalo that was attacked and crippled by a 2.8m dragon and suggests that buffalo as large a 590kg are sometimes killed by adults. Sometimes adult dragons attack ridiculously large prey but they usually select weak or young victims, They often feed on foals and young deer, even snatching baby animals from between the legs of the mother during birth. The dragons can identify heavily pregnant mammals by their smell and may attempt to induce miscarriage in those that are too large to be attacked successfully.
The popular perception of Komodo dragons is of scavengers that congregate around dead animals. This is due largely to the fact that dragons can be easily attracted to carrion, where they provide an excellent show by carving the carcasses up and swallowing it in enormous chunks. A 42kg animal is recorded as having eaten an entire 30kg boar in 17 minutes, How important carrion is in the diet of animals undisturbed by man remains uncertain. During times of seismic and volcanic upheaval they may encounter many corpses but usually only animals killed by other Komodo dragons may be available as carrion. They are certainly adept at eating large animals and never leave more than 13% of a corpse (intestines, fur and horns are usually ignored). All of the large animals eaten by modern day Komodo dragons have been introduced by man . Diamond (1987) suggested that a few thousand years ago pygmy elephants probably formed an important part of their diet. Green et al (1991) report that the metabolic rates of young Komodo dragons do not differ notably from those of other monitor lizards. Body temperatures of individuals drop as low as 20°C at night and can reach above 40°C during the day.
Many keepers (e.g. Lederer 1942) have commented on the intelligence of the dragons and in particular their ability to recognise individual people. Collins (1956) trained young specimens to jump through hoop and perform other dextrous acts to obtain food. The temperament of individual dragons varies enormously. Proctor (1929) published a picture of an infant playing with an unrestrained adult dragon at the London Zoo and stated "She would tear a pig to pieces but can be trusted with children". In later years Ms. Proctor was confined to an invalid chair and was accompanied on her excursions through the zoological gardens by a dragon (presumably the same specimen) who "could not be restrained from snapping at the beddedout flowers" (Anon 1968). However some Komodo dragons have a naturally belligerent nature. Auffenberg records that one wild individual was well known for its aggressive behaviour towards people and would follow human footprints on the beach and invade tents making off with articles of clothing. Not surprisingly the Komodo dragon is attributed with responsibility for many human deaths. Journalists like to blame the lizards for any unexplained deaths or disappearances, and more than one old soldier has been known to supplement his meagre income by displaying his war wounds to interested foreigners and describing them as the result of a dragon attack. Baron Rudolf Von Reding Biberegg is said to be the fust European victim of the dragons. He disappeared in July 1974, and only his hat, camera and a single bloodstained shoe were ever found (Blair & Blair 1988).
The Komodo dragon is heavily protected and all commercial trade in the species is outlawed. Its skin is unsuitable for the leather trade and its only therapeutic use is as some kind of dubious "swimming medicine" (Auffenberg 1981). However they are still sought after by some animal collectors and their is little doubt that an illicit trade in the animals exists. Breeding at zoos in Surabaya and Jakarta, Java, has been reported many times (de Jong 1944, Busono 1974, Horn & Visser 1989, Soebakir, pers comm, Linus, pers comm) but elsewhere the lizards had never reproduced successfully until the U.S. National Zoo in Washington DC produced 55 baby dragons from 3 clutches of eggs (Walsh et al 1993, Jaffrey 1995). They maintain a pair of dragons in a 58m2 enclosure with a soil substrate, at ambient temperatures of about 31°C which drop to 17°C at night. Basking areas of over 49°C are provided and the animals are fed several large rats each per week. Eggs are laid in a warmed nest area and hatch after about 237- 280 days incubation at 27.5-29°C in venniculite and water. The youngsters are housed apart, given UV light and reach a weight of about 300g after six months (Walsh et at 1993). Housed outside in Indonesia captive-bred dragons can reach lengths of 2m and weights of 20kg (females) or 30kg (males) after four years (Linus, pers comm).
Unfortunately all youngsters produced in the US to date have the same mother. which makes them of limited use to future captive breeding projects. As a result the controversial decision was taken not to allow her to breed again and to sacrifice her final clutch of eggs to scientific study. Nevertheless the work of the zoo has greatly raised awareness of the plight of the Komodo dragon in the USA and, most importantly, promises funding for further field studies and direct conservation action within Indonesia. The success of the American breeding programme now hinges very much on the success of the decision to catch and export a further four adult dragons to the USA (Jaffrey 1995). Should these animals fail to breed it will reinforce the claims of sceptics who consider the programme to be politically and financially motivated and believe that a complete ban on the removal of adult dragons from the wild is the best way to safeguard the future of one of the World's most remarkable animals. There is evidence that, on Komodo at least, female dragons are outumbered atleast 3: 1 by males (Darevsky & Kardarsan 1964, Auffenberg 1981) which makes the prohlems (If finding a compatible pair particularly formidable. Further accounts of the care of Komodo dmgons in captivity can be found in Brongersma (1932), Tanzer & Van Heurn (1938). Lederer (1942), Oesman (1967), Galstaun (1973) & Lange (1989). Up to date information on the Komodo dragon breeding project can be found in the newsletter Dragon Doings. puhlished oy the National Zoo in Washington DC.
Attribution / Courtesy: Daniel Bennett. 1995. A Little Book of Monitor Lizards. Viper Press U.K.
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