A guide to Australia’s dragon species
Animals occasionally blunder onto this baked, wind-blasted landscape, some leaving mummified remains as testament to their mistake. But out here on Lake Eyre (North), SA – where temperatures can soar to 60ºC, shade and food are almost non-existent and fresh surface water is absent – no vertebrates can survive. Except Lake Eyre dragons.
Australia’s 70-plus dragon species cover most of the continent. They laze beside ornamental ponds in eastern cities, cling to the buttressed trunks of rainforest trees, nestle among pebbles on stony plains and perch atop termite mounds in central deserts. One species even wanders around Tasmania and the mainland alps. But none match the Lake Eyre dragon for its sheer audacity in thriving in a virtually uninhabitable environment. Save for the resilient ants and windblown insects it eats, it has the place to itself. Survival hinges on an ability to tolerate high temperatures along with access to the cool, moist, silty sand beneath the salt crust.
There had been dust storms of late, so fellow naturalist Rod Hobson and I had come to the lake early to see the dragons emerge before the wind kicked in. The trick is to walk slowly – crunch, snap, crunch – and check for any movement about 10 m ahead. Lake Eyre dragons are painted in pale colours to reflect heat, and sprinkled with dark flecks and spots that match the small holes and pinnacles among the salt. To combat wind and glare, their small, deeply sunken eyes are black-rimmed and protected by fringed lids.
We see our first dragon at 8.30 a.m. When chased, dragons dive beneath a buckle in the salt crust, attempt to shelter in the shadow of their pursuer or crouch beside a lump of salt. In a harsh land where even predators fear to tread, the lizards seem less inclined to take more determined evasive action.
The life of a Lake Eyre dragon is as complex as its backdrop is simple. It’s a hierarchy of dominant and subservient males, mated and unmated females. From vantage points on old driftwood or elevated chunks of salt, dominant males scan for trespassers. Weaker males avoid bullying by being more active in the heat of the day or late in the afternoon, when alpha males are resting.
At the onset of breeding, females develop bright orange flushes on the throat and outer belly flanks. “Males find them irresistible,” says Devi Stuart-Fox, a University of Melbourne lecturer who is maintaining a captive research colony. “When they’re placed in the same tank, they just rush at the orange-bellied females and try to mate with them within seconds.” Courting males are persistent, aggressive and can cause injury, so fertilised females avoid them by running away or adopting a threatening stance with raised, flattened bodies and distended throats. If this fails, in an act of desperation unique among lizards, they flip onto their backs and lie belly-up to prevent male mating attempts.
The hardy dragons’ fortunes are dictated by infrequent, unpredictable and momentous weather events that unfold more than 1000km to the north. After a cyclone sweeps across the Gulf of Carpentaria, dumping a deluge over inland Queensland, it takes up to three months for floodwaters to reach Australia’s lowest region, carrying a cargo of nutrients, salt and even fish. It heralds a boom in the desert cycle and the Lake Eyre dragons must move. The entire species is forced to pack a spotted bundle onto its collective back and relocate to the adjoining sand dunes. Generations living as the sole residents on a buckled salt crust will spend more than a year jockeying with other species on the lake’s fringe. They must also escape predators, such as the voracious seagulls that visit until the lake evaporates.
Lizard colour and movement
It’s probably their perky, upright postures that give dragons a prehistoric appeal. They remind us of miniature dinosaurs, with their array of spiny crests, erectable frills and beards designed to alarm predators, impress mates or conceal their owners.
Dragons have the keenest vision of all Australian lizards, so appearance means a great deal to them. The sexes are usually differently coloured and marked, and they can brighten and fade with mood, temperature and season. Their alert stance helps them spy food and predators, recognise each other and communicate using a complex body language. Head bobs and dips, push-ups and tail lashes are all dragon-speak to convey territorial claims, threats, subservience, dominance or sexual and reproductive status. Some northern species are called “ta-ta” or “bye-bye” lizards because they wave their forelimbs as though bidding farewell.
A number of dragons broadcast ultraviolet signals invisible to humans. Red-barred dragons from the Flinders Ranges, SA, bob their heads to reveal UV blue and yellow throats. These flash important messages to other dragons without drawing attention from predators above. Up close, the males’ vivid red-and-black-slashed flanks are clearly visible to other dragons, but from a distance the colours merge and blend with the rocky background.
Confrontations between males are mostly ritualised puff and bluff. Red-barred dragons rear high on their limbs, doing push-ups and coiling their tails vertically over their backs. After watching eastern water dragons squaring off in the Brisbane Botanic Gardens at Mt Coottha, I decided to expose one to a mirror. He instantly saw a rival to be repelled. His attempts to appear larger by standing broadside and presenting his laterally flattened body, raised crest and expanded throat failed because the interloper matched him step for step. He then tried to initiate combat. Lying with chin flat to the ground, snout to snout with his reflection, he dared the other to make the first move, challenging his image to fight.
The battles, when they occur, are ferocious. During the four weeks he spent studying a population of bearded dragons on a golf course, Queensland Museum herpetologist Andrew Amey saw the damage that fighting males can inflict when they interlock their jaws. “Of the 45 large adult males I looked at, 19 had damaged snouts,” he said. “That means blood or little bits missing, and two had broken jaws.”
Dragons are cousins to iguanas and those odd, googly eyed lizards, the chameleons. They share the distinctive habit of seizing food with their tongues, but dragon tongues are short and thick, unlike chameleons’ long-distance projectiles. They all eat insects, although the larger varieties also scoff grass shoots, flowers and other vegetation.
Some swifter, long-limbed varieties, such as rock dragons, can perform acrobatic leaps to snatch low-flying insects from the air. Most dragons take whatever they can catch, but the slow-moving thorny devil eats only small black ants one at a time, taking more than 1000 in a sitting. When I examined thorny devil scats under a microscope, crunched ant bodies were no surprise but there were virtually no sand grains. All those ants and no misses!
All reptiles obtain their body heat from external sources and dragons are masters of the art. They spend most of their active lives in sunny environments, at first using their dark colours to absorb heat and then later their paler tones to reflect it.
Dragons also adopt poses that maximise or reduce direct exposure. Most function at temperatures similar to our own (about 37ºC). Some even operate in the low 40s, which in human terms would be a serious, if not life-threatening, fever. So much for cold-blooded reptiles.
In rainforests they may simply shuttle between shade and dappled sun, but in deserts it can be a fine line between basking and baking. The exaggerated poses they strike aid precise temperature regulation. Bodies are raised high and angled directly at the sun, with only the tips of their foreclaws and heels of their hind feet touching rocks that seem hot enough to fry eggs. Some even prop themselves upright on their back legs and tails. When virtually everything else has packed it in for the day, it is often only the hardy dragons that are still out.
Goannas dig dragons from their burrows, snakes snatch them from foliage and kestrels drop in on them from the sky. Small wonder these conspicuous lizards are capable of impressive bursts of speed. When pursued, many dragons raise their bodies and “pedal” on their hind legs, a habit that has earned some the name “bicycle lizards”. A sprinting long-nosed dragon has an estimated average speed of 22 km/h.
No-one has measured the speed of military dragons zipping between spinifex clumps, but for their size I’ve never seen anything as fast. The 14 cm long lizard seems to know it too, allowing a follower to get just so close before dashing a few metres, stopping, and squinting back over its shoulder. I remember stalking one on hands and knees with my camera. Each time I was about to take a picture the lizard would dart just out of focus. Then suddenly, in the blink of an eye, it zoomed in and snatched a fly off my knuckle.
Sometimes artful concealment is a better method of staying alive. Striking examples of camouflage can be found on the arid gibber plains. Using a strategy unique among Australia’s land-based vertebrates, round-headed pebble dragons crouch with legs tucked tight, imitating stones.
When it comes to bluffing its way out of strife, nothing can rival the frill-necked lizard’s trick of suddenly doubling its apparent size. The “frillie” normally rests concealed with its frill folded like a cape over its shoulders. When threatened, the mouth gapes and long slender bones like umbrella spokes pull out from the skull to support the paper-thin scaly frill. No other lizard in the world has a structure like it.
The once sweeping native grasslands of the Darling Downs, 200km west of Brisbane, are now reduced to some narrow road verges. In their place are crops such as cotton and sorghum. A couple of preserved earless dragons from that region have resided in the Queensland Museum’s collection for more than 30 years, but no-one seriously believed any wildlife worth bothering about would persist in these now cultivated fields. That changed in 2001 with the rediscovery of a community of earless dragons.
Earless dragons are so-named because their eardrum is covered by scaly skin. There are several different kinds, but scientists are not sure about the Darling Downs lizards. They were first believed to be a rare grassland species that vanished from Victoria in the 1960s and now exists only as isolated populations in the ACT and NSW. Recent genetic studies link them with a desert species, the four-pored earless dragon. They may even be unnamed and endangered.
Paula Halford, of the Darling Downs-based Mt Tyson Landcare group, has been helping coordinate the sale of locally made chocolate dragons, sold in information-packed wrappers, to raise money for these reptilian neighbours. It works for bilbies, so why not for dragons? “We’ve sold over 1100 chocolate dragons so far,” she says. “All the money goes to furthering studies of the dragon and its habitat and educating the local community in conserving the local flora and fauna.”
Fortunately, very few dragons have been pushed onto the threatened species list. The grassland earless dragon is of greatest concern, though several others have suffered disturbing declines. One species, known as Diporiphora convergens, remains an enigma. Just one tiny specimen, with a head and body length of 34mm, was collected in 1972 beside Admiralty Gulf in the Kimberley, WA. None have been seen since and it remains the only known Australian dragon species never photographed.
The mark of the dragon lizard
Dragons have left their mark on Brisbane resident Nikhila Williamson. This 21-year-old lizard fanatic sports two life-sized, bearded dragon tattoos: a sub-adult on her upper arm and an adult on her lower leg. At nine, Nikhila was diagnosed with leukaemia and she’s never forgotten the comfort her favourite pet dragon, Tubby, gave her during the dark months of treatment. “When I needed painful injections and operations, I used to think of Tubby and how calm she was,” she recalls. “We even smuggled Tubby into the hospital a few times.”
Tubby died several years ago but Nikhila keeps the lizard’s ashes in a pewter box and has a new cluster of pet lizards, mostly bearded dragons, including Ares, Clytomnestra and Hera. “Dragons are more intelligent than other lizards,” she says. “Each one has its own real personality – and they’re very self-centred.”
If I had my way, a dragon would be Brisbane’s official faunal emblem: a huge colony of reptilian city slickers thrives along the Brisbane River in the city’s heart. Large water dragons laze on the riverbank, paying no heed to the hum of traffic or the joggers, cyclists and commuters filing past. Brisbane supports a colossal variety of lizards – nearly 60 species, including six dragons, within the Greater Brisbane Region (the metro area and the surrounding 60–100 km). Almost half of these can be found within 5 km of the CBD. A suburb, a creek and a major arterial road share the name “Moggill”, derived from “maggil”, meaning water dragon in two local Aboriginal languages. Water dragons can be seen basking on rocks and branches wherever there is a dam, creek or duck pond. The South Bank Parklands, a busy recreation and dining area, is well stocked with the lizards, and they grace many waterside restaurants, lurking among diners’ feet ready to pounce on fallen morsels or cast an appraising eye over bare wriggling toes. And those are not statues among potted plants in Brisbane’s nurseries. They’re real dragons.
South Brisbane Cemetery is also home to a healthy community of bearded dragons. From a vantage point atop headstones they ambush prey and oversee their kin. Each time I spot them perched on the monumental masonry I find it entirely appropriate that the memorials we erect for our dead form part of a vital habitat for living, breathing dragons.
Steve K. Wilson thanks Denis and Rose Wooldridge, hospitable custodians of a healthy population of Darling Downs earless dragons at Bongeen, Qld.
A Complete Guide to Reptiles of Australia, Steve Wilson and Gerry Swan; Dragon Lizards and Goannas of South Australia, Terry Houston and Mark Hutchinson; Lizards of Western Australia II – Dragons and Monitors, Glenn Storr, Laurie Smith and Ron Jonstone.
Source: Australian Geographic Oct – Dec 2008