Australian Water Dragon
- Colour: grey, grey-brown to olive green body with patches of cream. It has black bands running across its body and tail and a "crest" of spines which start on its head and extend down its back and along its tail. Its belly is creamy-white to creamy brown-grey and the larger, breeding males have a red-orange chest and throat. One of two subspecies also has a broad black stripe running from behind its eye to its ear. Juveniles are light brown and their head and feet appear large for their body size.
- It has long, powerful legs and a long, strong tail with flattened sides to assist with swimming.
- There are loose folds of skin under its jaw.
- Size: around 80 - 90 cm long (from its snout to the end of its tail) two-thirds of which is tail. Males are bigger than females.
Diet: both plants and animals, including insects, frogs, small reptiles and mammals, yabbies and other water animals, fruits, berries and flowers. It can eat both on land and while underwater.
Movement: a semi-aquatic lizard, it spends much of its time lazing on rocks, logs and tree branches overhanging or alongside creeks and rivers, but will dive into the water at the first sign of danger. It is a good tree climber and a powerful swimmer. It walks on all fours, but will run on its back legs to gain speed. It sleeps either in vegetation or, particularly in colder weather, in water. In the cooler areas of its range, it digs a hole under a log or rock and hibernates from autumn through winter, emerging from late winter to mid spring.
Breeding: occurs from spring, starting in warmer and more northern locations. Mating occurs near waterways and the male is very territorial during this time. He will perform a series of head bobs, arm waves, tail flicks and arm waving to discourage other males from encroaching on his territory. After mating, the female lays between six and twenty eggs in a nest dug into soft soil above the floodline of a nearby waterway. Eggs are usually laid one or two hours before sunset. The female lies above the nest to deposit her eggs and then covers them with soil. The eggs hatch after about three months, and the young are completely independent from birth. There are usually two clutches each season, laid about one month apart.
What to Observe
- Hatched eggs
- Presence of juveniles
ClimateWatch Science Advisor
We expect lizards to start mating and laying eggs earlier in the year as a result of climate change warming the Earth. They may also start appearing in new areas as warmer temperatures enable them to live in environments that were previously too cold for them. In contrast, they may also start disappearing from areas that become too warm, particularly in upland areas where they can't move any higher to reach cooler regions.
When To Look
- From September through to April
- Mating occurs from spring and into early summer
- Eggs are laid in spring, from September in Cairns, early October in Brisbane, mid-late October in Sydney, early-mid November in Canberra, and early December in the Southern Highlands of NSW
- Second clutches are laid about one month later
- Eggs hatch about three months after being laid
The map below displays the accumulated observations of these species as reported by ClimateWatch observers, together with the layer showing how the range of the species might change between now and 2085, with orange areas indicating where the species might disappear, and green areas where the species range might expand.
Cogger H 2000. Reptiles and Amphibians of Australia. Reed Books, Australia.
Ehmann H 1992. Encyclopedia of Australian Animals: Reptiles. Angus and Robertson, Sydney.
Greer AE 1989. The Biology and Evolution of Australian Lizards. Surrey, Beatty and Sons, Chipping Norton, New South Wales.
Common or Eastern Bearded Dragon (Pogona barbata): its limbs and tail are shorter and it doesn't have the "crest" of spines running down its back, instead it has scales scattered all over its back, legs and tail. It also has a throat membrane which inflates when it feels threatened, while the Water Dragon has flaps of loose skin under its jaw.
Did You Know?
There are two subspecies of Water Dragon - the Eastern Water Dragon (Intellagama lesueurii lesueurii) and the Gippsland Water Dragon (Intellagama lesueurii howittii). The Gippsland subspecies is found in the southern areas.
It can remain underwater for up to 90 minutes!
The temperature of the nest during incubation determines whether more males or females hatch from the eggs. This is known as temperature-dependant sex determination (TSD). Nest temperatures are usually between 22°C and 32°C, with more females being born if the temperature drops below 26°C or rises above 28°C, and more males being born if the temperature remains between 26°C and 28°C.