Komodo dragon

REPTILIA: SQUAMATA: VARANIDAE: Varanus
Varanus komodoensis Owen, 1912 Komodo dragon / Ora Photos & text by Dr. Robert Sprackland.
Range: Restricted to a few small islands in the Lesser Sunda region of Indonesia, including Komodo, Rintja, Padar, and far western Flores.
Diagnosis: Adults are massive, the longest and heaviest confirmed lizard species on earth, growing to nearly 3 meters (10' 2") and weighing up to 110 kg (240 lbs). These monitor lizards are characterized by a yellow tongue, broad and flattened snout, laterally compressed tail, and little if any distinct pattern on specimens 1 m (3' 3") in total length.
Description: Above left: adult dragon at Sydney's Taronga Zoo; above right, a three-month old dragon at the Denver Zoo.
Natural History: This is particularly well studied endangered species. Pierre Pfeffer, Illya Darevsky and Walter Auffenberg have all made extended studies, Auffenberg having one the longest and most comprehensive work. Young Komodo dragons closely resemble Asian water monitors (Varanus salvator) in color and anatomy, but become drab and more stout bodied as they grow. Initially the young are expert and almost exclusive tree climbers, but become more terrestrial as they get larger. Adults will excavate or appropriate burrows along gullies and ravines, to which they retire at night and during the hottest part of the day. Komodo dragons are good swimmers, which probably accounts for their distribution on the tiny islands near Komodo.
Reproduction: Egg layers. This species was first reproduced outside of Asia at the U.S. National Zoo in Washington, DC, under the supervision of Trooper Walsch and Roger Rosscoe. This three-week-old baby dragon was born at the Denver Zoo in 2002.
Taxonomy & Relationships: The Komodo dragon was discovered "accidentally" after a Dutch flier crashed on the island and returned to Java with tales of big lizards. As an officer (and, presumably, gentleman), his stories were taken seriously enough to investigate, resulting in the capture of the first specimens for western examination in 1912. The systematic position of the dragon is still under debate. Early authors suggest it is ancestral and a "primitive" monitor. Others claim it is a more recently evolved form and a holdover from the Pliocene. It is one of four known varanids that possesses a yellow (rather than pink or purple) tongue.
Variation: Specimens from Flores Island--which represent most animals in zoos--are distinct in having reddish dorsal coloring. Animals from Komodo and Rintja are dull gray as adults.
Additional Comments: Despite the considerable fieldwork done with the Komodo dragons, many basic questions persist. For many years it has been claimed that the saliva is venomous. Some biologists point out that the diet of carrion probably contributes a population of toxic bacteria to the dragon's mouth, making a bite more septic than than produced by other large monitors. Recent chemical analysis bears this out, but also hints that dragon saliva may have high enough levels of digestive enzymes to produce or exacerbate envenomation-like symptoms in a bite victim. Komodo dragons and water monitors (Varanus salvator) occur together on Flores, but no published reports on possible interactions between the species are known. This is the only area known where two huge varanids overlap in range, making behavioral observations highly desirable.
Type Specimen:
Literature: Click on book to order. Auffenberg, Walter. 1980. The Behavioral Ecology of the Komodo Monitor. University of Florida Press. Eidenmüller, Bernd. 1997. Warane: Lebensweise, Pflege, Zucht. Herpeton, Offenbach. In German. ISBN: 3-9802892-7-3. King, Dennis and Brian Green. 1999. Monitors: the biology of varanid lizards. 2nd edition. Krieger Publishing. ISBN: 1-57524-112-9. Pfeffer, Pierre. 1965. Auf den Inseln des Drachen. Schwabenverlag Stuttgart. In German. Sprackland, Robert. 2001. Savannah & Grassland Monitors. Advanced Vivarium Systems. ISBN: 1-882770-53-6. Sprackland, Robert. 1992. Giant Lizards. TFH Publications. ISBN: 0-86622-634-6.