Australian water dragon

The specific name, lesueurii, is in honor of French naturalist Charles Alexandre Lesueur.[4]

The species was first described by John Edward Gray in 1831 as Lophura lesueurii, from a specimen collected by Lesueur & Péron at "Parramatta" or "Port Jackson".[5][6] Gray listed three species of Lophura: Cuvier's (Lophura Cuvierii Gray), Lesueur's (Lophura Lesueurii Gray), and beautiful (Lophura Concinna Gray, Physignathus Concinnus[lower-alpha 1] Cuvier).[5]

In 1845,[7] Gray separated Physignathus (P. concinnus & P. Lesueurii) from Lophura (L. amboinensis[lower-alpha 2] & L. Shawii[lower-alpha 3]). The Australian water dragon remained in Physignathus along with the Asian water dragon P. cocincinus until Wells and Wellington published the genus Intellagama in 1985.

The subspecies howitii was described by Frederick McCoy in 1884 as "the Gippsland water lizard". According to his description, it differs from the Queensland subspecies in the proportions of the head and the supra-ocular scales. Its sub-specific epithet commemorates geologist and magistrate Alfred William Howitt, who collected three specimens from the upper reaches of the Buchan River and sent them to McCoy.[8] Two of the specimens cannot be located,[9] the third is D1822[10] in the collection of the National Museum of Victoria, which was designated the lectotype by Coventry in 1970.[9] Hoser treats I. howitii as a separate species rather than a subspecies.[11]

Hoser (2020) proposed a third species: the Northern water dragon Intellagama wellsandwellingtonorum. The North Queensland Intellagama population, which extends from Townsville in the south through the wet tropical zone of Cairns to Cooktown in the north, is asserted to be allopatric with the mid-latitude population from Rockhampton south into New South Wales. The southern population ranges from Kiama south to Victoria. The northern dragons have smaller spines, "a series of 5–7 deep yellow, to yellowish-orange squarish to diamond-shped blotches along the mid flanks", and other colouration differences.[11]

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.[12] (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.)[13]

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.[14][15] Colour is less distinct in juveniles.[16]

Eastern water dragon

Intellagama lesueurii howitti, Gippsland water dragon basking in Canberra

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,[13] 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,[12] and in areas of higher population density, males exhibit displays of aggression toward other males including posturing, chasing and fighting.

Basking water dragon in Brisbane’s City Botanic Gardens.

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 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.

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, butcherbirds and other carnivorous birds.[17] They are also prone to becoming road kill due to the attraction of warm bitumen and concrete for basking.[17] 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.[18][19][20][21][22][23] Types of vegetation reportedly consumed include figs, lilly-pilly fruits, berries, and other fruits and flowers.[24][25][26]

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  Australian water dragon, Brisbane
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  Intellagama lesueurii lesueurii (eastern water dragon) at Kirra, Queensland
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  Intellagama lesueurii lesueurii (eastern water dragon)
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  Swimming across river in Melbourne
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  Head detail of the eastern subspecies
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  Intellagama lesueurii lesueurii (eastern water dragon) basking on a log in suburban Sydney
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  Intellagama lesueurii lesueurii swimming, Shoalhaven River, New South Wales
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  Australian water dragon surveying Sydney Harbour
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  Eastern water dragon at Brisbane Botanic Gardens
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  Eastern water dragon at Brisbane Botanic Gardens
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  Juvenile eastern water dragon in Roma Street Parkland, Brisbane, Queensland, Australia
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  Eastern water dragon in Brisbane Botanical Gardens
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  Head of an eastern water dragon poking out of a pond in Brisbane Botanical Gardens
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  Two male Australian eastern water dragons (Intellagama lesueurii lesueurii ) fighting.
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  Australian eastern water dragon basking in the sun at Blue Mountains (New South Wales)
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  A Dragon that has been marked for research purposes.
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  Adult male Australian Eastern Water Dragon in a tree overhanging a creek in suburban Brisbane
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  Northern form, showing yellow spots on flank (photographed near Cooktown).

• Boulenger GA. 1885. Catalogue of the Lizards in the British Museum (Natural History). Second Edition. Volume I. ... Agamidæ ... London: Trustees of the British Museum (Natural History). (Taylor and Francis, printers). xii + 436 pp. + Plates I-XXXII. (Physignathus lesueurii, pp. 398–399).

Wikimedia Commons has media related to Intellagama lesueurii.

Wikispecies has information related to Intellagama lesueurii.

• Video of male Gippsland Water Dragons fighting on Youtube
• Australian National Botanic Gardens Research
• Maruyama, K.; Langkilde, T. (1999). "Physignathus lesueurii " (PDF). Archived from the original (PDF) on 2008-07-27.
• "Physignathus lesueurii ". James Cook University - Discover Nature. Archived from the original on 2010-01-03. Retrieved 2009-04-19.
• Reptiles of Lamington National Park. "Physignathus lesueurii ". Archived from the original on 2004-03-22.
• "Physignathus lesueurii howittii ". ozanimals.com.
• Physignathus lesueurii at the Reptarium.cz Reptile Database