Komodo dragon

Komodo dragon, (Varanus komodoensis), world’s largest living lizard species. The Komodo dragon is a monitor lizard (family Varanidae), and it occurs on Komodo Island and a few neighboring islands of the Lesser Sunda Islands of Indonesia. The popular interest in the lizard’s large size and predatory habits has allowed this endangered species to become an ecotourist attraction, which has encouraged its protection.

Natural history

The lizard grows to 3 meters (10 feet) in length and a weight of about 135 kg (298 pounds), though the largest individuals (which are often males) can weigh as much as 165 kg (364 pounds). Adults range in color from brown to shades of red and gray with burly and muscular bodies, thick limbs, and a robust tail. Juveniles are smaller with prominent banding and spotted patterns. These monitor lizards have large heads and a rounded snout that contains a mouth full of sharp, serrated, backward-curving teeth.

Komodo dragons are carnivorous, and they possess a number of specialized physical adaptations and behavioral habits that allow them to consume prey. Although juveniles subsist on insects, birds and their eggs, and small mammals, adults frequently eat smaller members of their own species, and both newly hatched young and juveniles live in trees to avoid them. Adults can run swiftly and occasionally attack and kill human beings, and they sometimes even eat each other (see also cannibalism, animal).

Britannica Quiz

Wild Words from the Animal Kingdom Vocabulary Quiz

Although carrion is their main food source, they commonly wait along game trails to ambush larger mammals, including pigs, deer, and cattle. They seldom need to expend excess energy to chase and capture live prey directly. Their initial strike is often a surprise to the victim, delivering a venomous bite containing toxins that inhibit blood clotting. Should the victim escape and run away, it is thought to go into shock from rapid blood loss. Herpetologists also note that the physical trauma of the initial bite and the introduction of bacteria from the Komodo dragon’s mouth to the wound also play large roles in slowing and killing prey. Komodo dragons often come upon their prey in the process of dying or shortly after death.

Although most young are produced through sexual reproduction, females that are isolated from males sometimes produce offspring through parthenogenesis—an asexual reproductive strategy that does not require fertilization. Females dig burrows as deep as 9 meters (30 feet) and lay eggs that hatch in April or May. The newly hatched young are about 45 cm (18 inches) long.

Conservation status

Between 1996 and 2021 the International Union for Conservation of Nature and Natural Resources (IUCN) listed the Komodo dragon as a vulnerable species. Although the lizard’s population included fewer than 1,400 adults, ecologists noted that it was stable and at low risk from hunting and other threats. However, in 2021 the IUCN decided to list the Komodo dragon as an endangered species because climate models suggested that between 30 and 70 percent of the species’ habitat—a mix of dry savanna, scrub, mangroves, and beaches of sand and rock—would be lost by 2040 to increases in sea level. The conversion of natural areas to agriculture is also cutting into the Komodo dragon’s usable habitat, and there have been conflicts with people over dragon attacks on livestock. The risks associated with habitat loss are most pronounced on Flores, which hosts three of the eight Komodo dragon subpopulations. Such habitat loss increases the risk of further declines in the Komodo dragon’s overall population resulting in reduced genetic diversity (see also biodiversity loss).

Explore Britannica Premium!

The trusted destination for professionals, college students, and lifelong learners.

SUBSCRIBE