The Australian water dragon (''Intellagama lesueurii''), which includes the eastern water dragon (''Intellagama lesueurii lesueurii'' ) and the Gippsland water dragon (''Intellagama lesueurii howittii'' )

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

, is an arboreal agamid species native to eastern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

from Victoria northwards to Queensland. There may be a small introduced population on the south-east coast of South Australia.

Etymology

The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

, ''lesueurii'', is in honor of French naturalist Charles Alexandre Lesueur.

Description

Australian water dragons have long powerful limbs and claws for climbing, a long muscular laterally-compressed tail for swimming, and prominent nuchal and vertebral crests. (A nuchal crest is a central row of spikes at the base of the head. These spikes continue down the spine, getting smaller as they reach the base of the tail.)Australian National Botanic Gardens: Research into Water Dragons
Including their tails, which comprise about two-thirds of their total length, adult females grow to about 60 cm (2 feet) long, and adult males can grow slightly longer than one metre (39 inches) and weigh about 1 kg. Males show bolder colouration and have larger heads than females. Colour is less distinct in juveniles.

Species variation

The Australian water

dragon A dragon is a reptilian legendary creature that appears in the folklore of many cultures worldwide. Beliefs about dragons vary considerably through regions, but dragons in western cultures since the High Middle Ages have often been depicted as ...

is the only species of the genus ''Intellagama''. There are two

; ''Intellagama lesueurii lesueurii'' (eastern water dragon) and ''Intellagama lesueurii howitti'' ( Gippsland water dragon). ''Intellagama lesueurii lesueurii'' tends towards white, yellow and red on the throat and possesses a dark band behind its eye; ''Intelligama lesueurii howitti'' lacks this and instead has dark bands on either side of its throat, which is blotched with yellow, orange, or blue. Both subspecies are light greenish grey in overall colour with black bands running across their back, tail and legs. The water dragon can slowly change skin colour to aid its camouflage. The skin will shed during periods of growth.

Behaviour

Australian water dragons are extremely shy in the wild, but readily adapt to continual human presence in suburban parks and gardens. They are fast runners and strong climbers. When faced with a potential predator, they seek cover in thick vegetation, or drop from an overhanging branch into water. They are able to swim totally submerged, and rest on the bottom of shallow creeks or lakes for up to 90 minutes, to avoid detection. Both males and females display typical agamid behaviour such as basking, arm-waving and head-bobbing. Fast arm-waving signals dominance, while slow arm-waving signals submission. Males are territorial, and in areas of higher population density, males exhibit displays of aggression toward other males including posturing, chasing and fighting.

Breeding

Australian water dragons living in cooler Australian climates

hibernate Hibernation is a state of minimal activity and metabolic depression undergone by some animal species. Hibernation is a seasonal heterothermy characterized by low body-temperature, slow breathing and heart-rate, and low metabolic rate. It most ...

over winter. During spring, usually in early October, the female excavates a burrow about deep and lays between 6 and 18 eggs. The nest is usually in sandy or soft soil, in an area open to sun. When the mother has laid the eggs, she backfills the chamber with soil and scatters loose debris over it. Australian water dragons exhibit temperature dependent sex determination; the sex of the

hatchlings In oviparous biology, a hatchling is a newly hatched fish, amphibian, reptile, or bird. A group of mammals called monotremes lay eggs, and their young are hatchlings as well. Fish Fish hatchlings generally do not receive parental care, similar to ...

is determined by the temperature of the nest site. When the young are born they stay near the entrance of the burrow for some time before leaving home. When they finally leave the nest, they tend to group together away from the adult population.

Habitat

As its name suggests, the Australian water dragon is associated with water and is semi-aquatic. It can be found near creeks, rivers, lakes, and other water bodies that have basking sites such as overhanging branches or rocks in open or filtered sun. The species is very common in the rainforest section of

Brisbane Botanic Gardens, Mount Coot-tha The Brisbane Botanic Gardens (formerly the Mount Coot-tha Botanic Gardens and informally the Toowong Botanic Gardens) are located from the Brisbane CBD at the foot of Brisbane's tallest mountain, Mount Coot-tha in the suburb of Mount Coot-th ...

in Queensland, and a monument has been built to them there. There are anecdotal reports of a small colony living on the Sixth Creek in the Forest Range area of South Australia, hundreds of kilometers outside their natural range, which were probably introduced there during the 1980s by a local reptile enthusiast.

Predators, threats and diet

Australian water dragons are prey to carnivorous birds, snakes, cats, dogs, and foxes. Nestlings and smaller juvenile water dragons are vulnerable to predation by kookaburras, currawongs,

butcherbird Butcherbirds are songbirds closely related to the Australian magpie. Most are found in the genus '' Cracticus'', but the black butcherbird is placed in the monotypic genus '' Melloria''. They are native to Australasia. Taxonomy Together with th ...

s and other carnivorous birds.Australian National Botanic Gardens: Predators of Water Dragons
They are also prone to becoming road kill due to the attraction of warm bitumen and concrete for basking. The Australian water dragon's diet depends on its size. Juveniles and yearlings tend to feed on spiders and small insects such as ants, crickets, and caterpillars. When they get bigger, so does their prey. An adult diet includes small rodents, such as baby mice, other reptiles, frogs, fish, crabs, yabbies, molluscs, worms and eggs, although insects are still the most commonly consumed. Types of vegetation reportedly consumed include figs, lilly-pilly fruits, berries, and other fruits and flowers.

Gallery

File:Physignathus lesueurii paulbrian.jpg, Australian water dragon, Brisbane File:Water Dragon 001.jpg, ''Intellagama lesueurii lesueurii'' (eastern water dragon) at Kirra, Queensland File:1A B-DRAGON.JPG, ''Intellagama lesueurii lesueurii'' (eastern water dragon) File:Gippsland-Water-Dragon---Physignathus-lesueurii-howittii.jpg, Swimming across river in Melbourne File:Eastern Water Dragon Clontarf.jpg, Head detail of the eastern subspecies File:Physignathus lesueurii lesueurii (Sydney, 2010-03-24).jpg, ''Intellagama lesueurii lesueurii'' (eastern water dragon) basking on a log in suburban

Sydney Sydney ( ) is the capital city of the state of New South Wales, and the most populous city in both Australia and Oceania. Located on Australia's east coast, the metropolis surrounds Sydney Harbour and extends about towards the Blue Mountain ...

File:Eastern water dragon.jpg, ''Intellagama lesueurii lesueurii'' swimming,

Shoalhaven River The Shoalhaven River is a perennial river that rises from the Southern Tablelands and flows into an open mature wave dominated barrier estuary near Nowra on the South Coast of New South Wales, Australia. Location and features The Shoalhaven ...

, New South Wales File:Water Dragon Sydney Harbour.JPG, Australian water dragon surveying

Sydney Harbour Port Jackson, consisting of the waters of Sydney Harbour, Middle Harbour, North Harbour and the Lane Cove and Parramatta Rivers, is the ria or natural harbour of Sydney, New South Wales, Australia. The harbour is an inlet of the Tasman Sea (p ...

File:1523239 10152141733016206 1259332200 o.jpg, Eastern water dragon at Brisbane Botanic Gardens File:857853 10152141732796206 1865575802 o.jpg, Eastern water dragon at Brisbane Botanic Gardens File:Eastern Water Dragon 20140125.jpg, Juvenile eastern water dragon in Roma Street Parkland, Brisbane, Queensland, Australia File:AndrewMercerIMG 5618 Australian Water Dragon.jpg, Eastern water dragon in Brisbane Botanical Gardens File:AndrewMercerIMG 5585 Australian Water Dragon.jpg, Head of an eastern water dragon poking out of a pond in Brisbane Botanical Gardens File:Male Eastern Water Dragons Fighting (IMG8022).jpg, Two male Australian eastern water dragons (''Intellagama lesueurii lesueurii'' ) fighting. File:Australian Eastern Water Dragon basking in the sun at Blue Mountains NSW Australia.jpg, Australian eastern water dragon basking in the sun at Blue Mountains (New South Wales) File:Intellagama Lesueurii with Red Spots - AndrewMercer - DSC10821.jpg, A Dragon that has been marked for research purposes. File:Adult male Australian Eastern Water Dragon in a tree.jpg, alt=, Adult male Australian Eastern Water Dragon in a tree overhanging a creek in suburban Brisbane

References

External links

Video of male Gippsland Water Dragons fighting on Youtube

* * * * * {{Taxonbar, from=Q738712 Agamidae Agamid lizards of Australia Reptiles described in 1831 Taxa named by John Edward Gray