Introduction

The Komodo Dragon (Varanus Komodoensis) is the largest lizard in the world, and is endemic to five islands in the Lesser Sundas. The largest populations are found in Komodo National Park which includes Komodo, Padar, Gili Montang and Rinca. There is also a relatively large population on the island of Flores. In the wild, Komodo Dragons can grow up to 3m in length and on average weigh around 70kg. They can live for more than 30 years, and are the top predators in their island habitats.

Behaviour and ecology

Komodo dragons are mainly found in grassland and woodland habitats. Adults hunt on the ground, whereas juveniles hunt in trees to avoid cannibalism from older individuals. They rely mainly on stealth for hunting. They have reasonably good eye-sight and can detect prey up to 300m away. Their eyes can discern moving objects better than stationary ones and therefore movement of prey is important for hunting. Although vision and hearing are important, Komodo Dragons rely mainly on their sense of smell for hunting. Their forked tongues are used to sense the air and then drawn into the mouth where it interacts with organs in the roof of the mouth. Differences in concentration of airborne particles between the left and right tongue tips allows them to determine the direction of the food-source.

Komodo Dragons feed mainly on mammals including deer, rodents and monkeys. Large, sharp teeth and powerful jaws enable them to capture and tear apart prey. Their saliva contains several strains of bacteria, including some which are highly infectious; if a komodo dragon attacks its prey but fails to kill it, the prey may die several days later from bacterial infections, and will consequently be consumed by other Komodo Dragons.

Females lay their eggs in September either in nests built on hillsides or in existing megapode nests. Most nests are found in open coastal deciduous forest.

Komodo Dragon

Threats

The main threats to the Komodo Dragon are poaching of prey species and habitat loss. The Komodo Dragon is described as vulnerable according to the IUCN Redlist of threatened species. Estimates suggest that there are only several thousand individuals living in the wild, most of these inhabiting the islands of Komodo and Flores.

The Komodo Dragon has become extinct on the small island of Padar within Komodo Island National Park. This appears to have been caused by habitat modification by humans and poaching of deer, their main prey. On the island of Flores, clearance of coastal forest and deer poaching threaten existing populations. Habitat loss has already caused the loss of the species over a 150 km long area along the northwest coast of Flores.

Conservation

Populations with distinct genetic characteristics have been identified for conservation management. DNA analysis has revealed high genetic diversity on Komodo Island. However, isolated populations such as those on Gili Montang had much less variation, and are considered as vulnerable. These findings have important implications for the potential reintroduction of a population to areas where it has become extinct, such as the island of Padar; High genetic diversity would be important to prevent inbreeding on this small island.

Komodo National Park attracts thousands of visitors each year, and ecotourism provides an important income to help maintain and manage the park. On Flores, population density is estimated to be 60% lower than in Komodo national Park. Protection of monsoon forest on the island is crucial to protecting the species in the long term.