Komodo Dragon (Varanus komodoensis): Facts and Habitat

Appearance

A Komodo dragon looks like a scaled-up monitor lizard: a long, flat head, a thick neck, a powerful tail as long as its body and strong, bowed legs with curved claws. Adults are mostly gray, brown or dull reddish, often dusty from the ground they lie on. Young dragons are more colorful, with yellow and green bands and speckles that help hide them in trees.

The skin is reinforced with tiny bones called osteoderms, set inside the scales like a coat of chain mail. These bones become more extensive as a dragon ages, and they are absent in hatchlings. A long, deeply forked yellow tongue flicks in and out constantly, picking up scent particles from the air.

The mouth holds about 60 serrated, backward-curving teeth up to 2.5 cm (1 in) long, shaped much like the teeth of meat-eating dinosaurs. They are replaced throughout life. A 2024 study found that the tips and cutting edges of the teeth carry an orange, iron-rich coating that helps keep them sharp.

How big do Komodo dragons get?

Males are larger than females. Commonly cited averages are about 2.6 m (8.5 ft) for adult males and 2.3 m (7.5 ft) for females. Wild adults usually weigh around 70 to 90 kg (150 to 200 lb), and captive dragons are often heavier because they get regular meals and move less.

The largest wild dragon measured in a scientific study was about 3.04 m (10 ft) long and weighed 81.5 kg (180 lb) without its stomach contents. The biggest verified captive animal measured about 3.1 m (10 ft 2 in) and weighed 166 kg (366 lb), but that figure included a recent meal. Claims of wild dragons over 4 m (13 ft) have never been confirmed. The full story of records and growth is in how big do Komodo dragons get.

Habitat and range

Komodo dragons have one of the smallest ranges of any large predator. They live on Komodo, Rinca, Gili Motang and Gili Dasami (also called Nusa Kode), all within Komodo National Park, and on the western and northern coasts of the much larger island of Flores. These islands belong to the Lesser Sunda chain in the province of East Nusa Tenggara. A population on the small island of Padar disappeared by the 1970s, probably after its deer prey was poached.

They prefer hot, dry, low-lying country: open savanna with tall grass and scattered palms, tropical dry forest and the edges of monsoon forest, from beaches up to the lower hills. They rarely use higher, cooler ground. The species is older than its small range suggests. Fossils show that Komodo dragons lived in Australia from about 3.8 million years ago, and they have been on Flores for well over a million years.

Diet and hunting

Komodo dragons are carnivores. Adults hunt Javan rusa (also called Timor deer), wild pigs and water buffalo, along with goats, horses and smaller animals, and they eat a great deal of carrion. A dragon ambushes prey from a hidden spot beside a game trail, charges in a short burst and slashes at the legs, belly or throat. Many large prey animals die within minutes from blood loss.

A dragon can eat up to about 80 percent of its own body weight in a single meal, then rest for days while it digests. Large adults may need only about a dozen big meals a year. Young dragons eat insects, geckos, small birds and eggs, and they spend much of their first years in trees, partly to avoid being eaten by adults. For the details see what do Komodo dragons eat.

Venom and the bacteria myth

For decades people believed that a Komodo dragon killed with deadly bacteria in its saliva, biting prey and waiting for it to die of infection. Research since 2009 has changed that picture. Scans and dissections revealed venom glands in the lower jaw that release proteins which interfere with blood clotting and lower blood pressure. Studies of the mouth bacteria found ordinary microbes similar to those of other carnivores.

Scientists still debate how much the venom adds compared with the damage of the bite itself, which is already severe because of the serrated teeth and strong neck. The explanation is in are Komodo dragons venomous. The closely related venom question for North America’s only large venomous lizard is covered on the Gila monster page.

Behavior

Komodo dragons are solitary, active by day and dependent on the sun for warmth. They bask in the morning, shelter in the shade or in burrows during the hottest hours, and sleep in burrows they dig with their front claws, which helps them hold body heat through the night. They can run in short sprints of up to about 20 km/h (12 mph), swim between islands and dive to around 4.5 m (15 ft).

Smell guides almost everything a dragon does. By flicking its tongue and swinging its head from side to side, it can pick up the scent of a carcass from several kilometers away when the wind is right. At a large carcass, several dragons often feed together, with the biggest animals eating first. Smaller dragons signal submission with body posture and hissing, while males of similar size may rear up on their hind legs and wrestle.

Reproduction and life cycle

Mating takes place mainly from May to August. Males wrestle for access to females, standing on their hind legs and grappling until one is pushed to the ground. Females lay clutches of about 20 eggs, often around September, usually in a hole dug into the mound nest of a ground bird called the orange-footed scrubfowl, or in a burrow on a hillside. Many females dig several decoy holes and guard the nest for a time.

The eggs incubate for about seven to eight months, so the young hatch around March or April, when insects are plentiful. Hatchlings are around 40 to 46 cm (16 to 18 in) long and weigh about 100 g (3.5 oz). They climb trees at once. Dragons take roughly 8 to 11 years to reach maturity, and wild individuals are estimated to live about 30 years.

Females can also produce young without a male, a process called parthenogenesis that was first proven in two British zoos in 2006. Because of the way sex chromosomes work in this species, all of those offspring are male. Read more in can Komodo dragons reproduce without males.

Predators and threats

Adult Komodo dragons have no natural predators. The main danger to eggs and young comes from other Komodo dragons: adults eat juveniles, and cannibalism makes up a noticeable share of the diet of big dragons. That is why young dragons stay in trees and sometimes roll in dung, which may make them less appealing to adults.

The real threats today come from people and the changing climate. Poaching of deer and pigs removes the dragons’ food, especially on Flores and the smaller islands. Habitat is lost to farming, settlements, roads and fires, and some dragons are poisoned or killed in conflicts over livestock. Illegal wildlife trade remains a problem: in 2019 Indonesian police broke up an attempt to smuggle 41 young dragons out of the country.

Conservation status

The IUCN Red List moved the Komodo dragon from Vulnerable to Endangered in 2021. The main reason is its tiny range, which makes it unusually sensitive to climate change. Rising sea levels and a hotter, drier climate are expected to shrink the low-lying habitat it depends on over the coming decades, with populations on Flores thought to be most at risk.

Komodo National Park was created in 1980 to protect the dragon and its islands, and it became a UNESCO World Heritage Site in 1991. Surveys in the 2010s counted roughly 3,000 dragons, with numbers fairly stable on Komodo and Rinca but falling on smaller islands. The species is listed on CITES Appendix I, which bans international commercial trade, and it is protected under Indonesian law.

Komodo dragons and people

Western scientists learned of the Komodo dragon only in 1910, after Dutch colonial officials heard stories of a “land crocodile”. The 1926 expedition of W. Douglas Burden brought back specimens, popularized the name “Komodo dragon” and is often said to have inspired the film King Kong (1933). Today the park draws large numbers of tourists, who visit with ranger guides.

Komodo dragons rarely attack people, but they are large predators and occasionally do. Park records list 24 attacks between 1974 and 2012, five of them fatal, mostly involving villagers living inside the park. Zoos around the world now keep and breed the species, and Surabaya Zoo in Indonesia holds one of the largest collections outside the wild. As the heaviest lizard on Earth, the Komodo dragon also earns a place among the largest animals in the world.