Komodo dragon (Varanus komodoensis)

Also known as: Komodo monitor, Ora
  
French: Dragon Des Komodos, Varan De Komodo
Spanish: Varano De Komodo
KingdomAnimalia
PhylumChordata
ClassReptilia
OrderSquamata
FamilyVaranidae
GenusVaranus (1)
SizeMales: up to 90 kg (2)
Females: less than 50 kg (2)
Female length: less than 2 m (2)
Male length: up to 2 m (2)
Top facts

The Komodo dragon is classified as Vulnerable (VU) on the IUCN Red List (1), and listed on Appendix I of CITES (3).

The Komodo dragon (Varanus komodoensis) is the largest lizard in the world (4), and with its ancient appearance and evocative name, the Komodo conjures up the stuff of legends. The heavy-set body of the Komodo dragon is long with stocky legs and a long muscular tail; the scaly skin is greyish-brown all over (4). Dragons from the island of Flores however, are earthen-red in colour with a yellow head (2). The juvenile Komodo dragon has a more striking pattern with very variable combinations of bands and speckling in yellow, green, grey and brown (4). The Komodo dragon has a well-developed sense of smell and its long, forked yellow tongue resembles the mythical, fire-breathing dragons of its name.

Found on the island of Komodo in Indonesia, from which the Komodo dragon takes its common name, and also on the neighbouring islands of Rinca and Flores (2).

The three islands where the Komodo dragon lives are all volcanic; it inhabits the lower monsoon forests and savannah up to about 700 metres above sea level (2).

The adult Komodo dragon is generally solitary, although groups may gather around a kill. It is a powerful predator and the Komodo dragons’ voracious appetite has further fuelled its ferocious image. Both carrion and live prey are consumed; adults ambush deer, water buffalo and wild pigs, and carcasses can be detected from up to 10 km away (2). The large powerful jaws tear at prey and large amounts can be eaten with surprising speed, only a small percentage of the kill is discarded (5). The Komodo dragon can eat up to 80% of its own body weight at one time (2). Recent research into the feeding behaviour of the Komodo dragon has shown that it is actually venomous, possessing complex venom glands in its jaw, which excrete a variety of toxic substances that prevent blood clotting and lower blood pressure in its prey. In contrast to the elaborate venom injection system used by snakes, the Komodo dragon’s venom is administered relatively crudely, seeping into the large wounds made by the teeth. This means that even if the injured animal escapes, it will rapidly succumb to shock and blood loss induced by the venom. It was previously believed that toxic bacteria found in the Komodo dragon’s mouth help to take down prey by infecting bite wounds, leading to fatal blood poisoning. However, studies have indicated that this may not be the case, and that the venom is the main agent by which prey is subdued (6).

The mating season occurs between May and June (2); the male Komodo dragon will compete for access to receptive females by wrestling, rearing-up on the hind legs supported by the thick, muscular tail (5). In July and August, the female lays and then incubates a clutch of around 25 eggs in depressions dug into the ground (4). Eggs incubate for up to nine months before hatching (2). Juveniles are extremely vulnerable to predation and spend their first year of life in the relatively protected habitat of the trees (7). Young dragons will feed on snakes, lizards and rodents (4).

The population of the Komodo dragon today is estimated to be a mere fraction of its size 50 years ago (4). Causes of this decline are widespread habitat loss throughout the region, a loss of prey species and hunting (4). No Komodo dragons have been seen on the island of Padar since the 1970s, the result of widespread poaching of the deer that constitute their chief prey source (5).

Komodo and surrounding islands lie within the Komodo National Park (5). Law has protected the Komodo dragon since the 1930s (4), and international trade is prohibited by Appendix I of the Convention on International Trade in Endangered Species (CITES) (3). An important tourist trade has sprung-up around these spectacular creatures, bringing over 18,000 visitors to the area each year; it is hoped that this economic incentive will help to safeguard the future of these awesome dragons (5).

To learn more about Komodo dragon conservation see:

For more general information about the Komodo dragon, visit:

Authenticated (7/7/03) by Kevin Buley, Curator of Lower Vertebrates and Invertebrates, Chester Zoo.
http://www.chesterzoo.org/

  1. IUCN Red List (May, 2009)
    http://www.redlist.org
  2. Buley, K. (2003) Pers. comm.
  3. CITES (May, 2009)
    http://www.cites.org
  4. Burnie, D. (2001) Animal. Dorling Kindersley, London..
  5. Ciofi, C. (1999) The Komodo Dragon. Scientific American, March.
  6. Fry, BG et al. (2009) A central role for venom in predation by Varanus komodoensis (Komodo Dragon) and the extinct giant Varanus (Megalania) priscus. Proceedings of the National Academy of Sciences, 106: 8969 - 8974.
  7. American Museum of Natural History (April, 2003)
    http://www.amnh.org/nationalcenter/Endangered/ora/ora.html