What are eastern water dragons?
Eastern water dragons are medium to large-sized lizards that live around creeks, rivers and lakes in eastern Australia.
The scientific name of the eastern water dragon is Intellagama lesueurii. The Darug people of Sydney refer to lizards as deregal.
Eastern water dragons are one of the oldest groups of Australian reptiles. While many other groups of reptiles have evolved (changed) over time the dragon has barely changed in 20 million years!
What do eastern water dragons look like?
Eastern water dragons have a distinctive tail that is much longer than their body as well as five claws on each of their limbs. Eastern water dragons have a row of spines which runs all they way from their heads down their backs to the tip of their long tails. Males have larger heads than females, with stronger jowls and crests. Their colours vary from grey to dark green to brown. They have a dark stripe behind their eyes and often have a reddish tinge on their throats and chest.
Where do eastern water dragons live?
Eastern water dragons are subaquatic which means they live partly on land, and partly in water. They live in areas of native vegetation around creeks, lakes and rivers with clean water. They prefer areas with plenty of trees and large rocks close to the water’s edge.
As reptiles, they are cold-blooded and are often seen sunning themselves on rocks or branches along creeks and rivers. During the colder months they lie still in burrows scraped out in riverbanks or between boulders and logs, they pack dirt into the opening of the burrow to seal themselves off.
What do eastern water dragons eat?
Adult eastern water dragons are omnivorous. They can eat many things but they prefer a mixed diet of insects, frogs, yabbies, fruit, flowers and berries.
They forage (search) for food in many different places. On the ground for fallen berries and insects such as ants. In the branches of trees for flowers, fruits and arboreal invertebrates such as cicadas. In the water they search for molluscs and crustaceans. In salty intertidal zones they have even been reported foraging for algae and crabs!
As juveniles, eastern water dragons are completely insectivorous, eating the same sorts of insects as adults. Juvenile dragons have even been observed feeding on mosquitoes which they catch by jumping up into the air!
How are eastern water dragons adapted to their environment?
Eastern water dragons live in rocky bushland environments close to water where, to survive they must find enough food, hide from predators and stay warm. These dragons have a variety of features and behaviours that help them meet the challenge of survival in their complex environment.
When it comes to hiding eastern water dragons are masters in the art of camouflage. They will often remain completely still and rely on their mottled, striped colouring to blend in with the rocks, fallen leaves and shadows. If a predator comes close it is only at the very last moment that they will break cover and drop into the water or run away.
Eastern water dragons can drop from rock ledges and branches into the water where, thanks to their long muscular tails, they are fast, powerful swimmers. They can also slow their heart rate down and stay underwater for up to an hour.
On land, eastern water dragons can run quickly to cover using only their back legs. Thanks to their five strong toes with claws they can quickly climb steep rocks. They can also use their toes and claws to dig and can flatten their bodies to squeeze into tight rocky spaces.
Eastern water dragons are different to most other types of lizards in that they can also grab their food with their tongues as well as their jaws. This helps them quickly grab and swallow large wriggling insect prey. They communicate to each other by bobbing their heads, licking their lips, inflating their throat pouches, doing push-ups and waving their front legs! Eastern water dragons can even sleep while floating in the water, with just their nostrils showing above the surface!
What is the life cycle of eastern water dragons?
Eastern water dragons can live for up to 20 years. They often live together in large groups made up of several females, youngsters and a dominant male who will defend as much of the territory as possible from other males.
They mate near water during spring. Females lay 10 to 20 small eggs in nests away from the water during November and December. The young eastern water dragons usually hatch in January and February.