The Komodo dragon is the largest and heaviest lizard in the world. These lizards have a venomous bite and their group behavior in hunting is exceptional in the reptile world. Komodo dragons have a tail as long as their body and a long, yellow, deeply forked tongue. Their skin is usually gray in color reinforced by armored scales, which contain tiny bones called osteoderms that function as a sort of natural chain-mail. This rugged hide makes Komodo dragon skin a poor source of leather. Additionally, these osteoderms become more extensive and variable in shape as the Komodo dragon ages, ossifying more extensively as the lizard grows. These osteoderms are absent in hatchlings and juveniles, indicating that the natural armor develops as a product of age and competition between adults for protection in combats over food and mates.
Komodo dragons are found in the Indonesian islands of Komodo, Rinca, Flores, and Gili Motang. These lizards prefer hot and dry places and typically live in dry, open grassland, savanna, and tropical forest at low elevations.
Komodo dragons are most active in the day, although they exhibit some nocturnal activity. They are solitary and come together only to breed and eat. These lizards are capable of running rapidly in brief sprints up to 20 km/h (12 mph), diving up to 4.5 m (15 ft), and climbing trees proficiently when young through use of their strong claws. To catch out-of-reach prey, Komodo dragons may stand on their hind legs and use their tail as a support. As they mature, their claws are used primarily as weapons, as their great size makes climbing impractical. For shelter, Komodo dragons dig holes with their powerful forelimbs and claws. These holes can measure from 1 to 3 m (3.3 to 9.8 ft) wide. Because of their large size and habit of sleeping in these burrows, these lizards are able to conserve body heat throughout the night and minimize their basking period the morning after. Komodo dragon hunt in the afternoon, but stay in the shade during the hottest part of the day. These special resting places, usually located on ridges with cool sea breezes, are marked with droppings and are cleared of vegetation. They serve as strategic locations from which Komodo dragons ambush deer.
Komodo dragons are carnivores. Although they have been considered as eating mostly carrion, they will frequently ambush live prey. Their diet is wide-ranging and includes invertebrates, other reptiles (including smaller Komodo dragons), birds, bird eggs, small mammals, monkeys, wild boar, goats, deer, horses, and water buffalo. Young Komodos will eat insects, eggs, geckos, and small mammals, while adults prefer to hunt large mammals. Occasionally, they attack and bite humans.
Komodo dragons exhibit a rare behavior for lizards; they may be monogamous and form "pair bonds". Mating occurs between May and August, with the eggs laid in September. During this period, males fight over females and territory by grappling with one another upon their hind legs, with the loser eventually being pinned to the ground. These males may vomit or defecate when preparing for the fight. The winner of the fight will then flick his long tongue at the female to gain information about her receptivity. Females are antagonistic and resist with their claws and teeth during the early phases of courtship. Other courtship displays include males rubbing their chins on the female, hard scratches to the back, and licking. Females lay their eggs from August to September and may use several types of the locality. They make many camouflage nests/holes to prevent other dragons from eating the eggs. Clutches contain an average of 20 eggs, which are incubated around 7-8 months. Hatching is an exhausting effort for the neonates, which break out of their eggshells with an egg tooth that falls off before long. After cutting themselves out, the hatchlings may lie in their eggshells for hours before starting to dig out of the nest. They are born quite defenseless and are vulnerable to predation. Young Komodos spend much of their first few years in trees, where they are relatively safe from predators. They become reproductively mature at 8-9 years of age.
Volcanic activity, earthquakes, loss of habitat, fire, loss of prey due to poaching, tourism, and illegal poaching of the dragons themselves have all contributed to the vulnerable status of the Komodo dragon.
According to the Wikipedia resource, in 2015 the total population size of the Komodo dragon was 3,014 individuals. Currently, this species is classified as Vulnerable (Vu) on the IUCN Red List.
As a result of their size, Komodo dragons dominate the ecosystems in which they live. They are top predators and also scavengers. These lizards eat recently dead animals preventing the spread of disease and assist with a sort of “natural recycling”.