|Potrait of one of our Komodo dragons Varanus komodoensis at Durrell. Credit: Dan Lay|
Growing up to a massive 3 metres in length and 80 kilograms in weight, the Komodo dragon is the largest species of lizard in the world.
Armed with more than 60 serrated teeth and an assortment of deadly oral bacteria, they are top predators. In the wild they feed upon buffalo, wild pigs and deer, consuming up to 80% of their own body weight in one meal, the equivalent of an average adult man eating around 64 pizzas in one sitting!
Recent research has shown the Komodo dragon blood plasma could be used to develop medication for humans as it contains powerful antibacterial substances that could be developed as new antibiotics.
Female Komodo dragons can have up to 30 eggs in a clutch and can produce babies without ever mating, an extraordinary process known as parthenogenesis. After hatching, the young dragons spend the first few years of their lives living high in trees, to avoid being eaten by larger dragons.
In the wild, ground nests of the Megapode bird, Megapodius reinwardt, are often used by female Komodo dragons for laying eggs. These nests are mounds of earth and twigs more than 150cm high and 5m-6m in diameter. The dragons avoid ‘putting all of their eggs in one basket’ by laying their eggs in a number of separate nests, especially to avoid mass predation. The mean clutch size is 18.7 eggs with an average incubation period of 220 days. Komodo dragons are in fact monitor lizards, of which there are over 45 species, all in the genus Varanus.
Monitor lizards are the most intelligent of all lizards; experiments have shown that some can even count! In the experiments, lizards were conditioned by feeding them groups of four snails in separate compartments with movable partitions that opened one at a time to allow the monitor lizards to eat each of the four snails. When the fourth snail had been eaten, the lizards were allowed into another chamber containing four more snails. After such conditioning, one snail was removed from some snail groups. The lizards searched extensively for the missing fourth snail, even when they could see and get to the next group. Such experiments have shown that monitor lizards could count up to six after which they just considered them ‘lots’.
|Komodo dragon using a ‘kong-ball’ enrichment feeder at Durrell. Credit: Dan Lay|
To keep our dragons healthy we closely replicate circumstances that dragons find in the wild. One of these scenarios is making them work for their food as they would have to in the wild. To do this we use a ‘kong-ball’ which can be seen in the photo to the right. We put the dragons’ food in this and hang it or hide it somewhere in their enclosure. The dragons then have to find this and use their claws and snout to retrieve the food. This simulates natural behaviour where a young dragon would probe a tree for nests of birds or the nook of a small lizard. We have also begun training our dragons. This allows us to keep the dragons both physically and mentally active and will help us to be able to give them proactive health care and negate the need for them to be caught up. This will be especially important for when they are fully grown dragons.
Both of our Komodos are important animals in the European Endangered Species Breeding Programme, an insurance population for the species in zoos. By working with Komodo dragons we are also supporting the Wae Wuul Nature Reserve and it’s dragons.
Murphy, J., C. Ciofi, C. De La Panouse, T. Walsh. 2002. Komodo Dragons: Biology and Conservation. Washington: Smithsonian Institution Press.
Other Vulnerable Animals