40 Fun Facts About Thorny Devil

The thorny devil, a spiky lizard of the Australian outback, eats almost nothing but which insects?

Ants are virtually all a thorny devil eats, and it is especially fond of very small ones. Tiny stones and sticks found in its stomach were probably being carried by the prey.

What does the spiny knob on the back of a thorny devil's neck look like to a predator?

A false head is what the knob imitates, and the thorny devil shows it off by tucking its real one down between its front legs. The decoy is only soft tissue.

Which effect, the one that draws water up a paper towel, moves water across a thorny devil's skin?

Capillary action pulls water along tiny grooves between the scales, so a thorny devil can drink just by standing in a puddle. The grooves work even uphill, against gravity, along its legs.

Besides relying on its spines, what does a thorny devil do to its body when a predator disturbs it?

It puffs up with air, inflating like a little puffer fish, which makes the spiky body even harder to swallow or handle.

What happens to a thorny devil's pale yellow and red colouring when the desert air gets cold?

It turns darker, shifting rapidly to a drab olive whenever the lizard is cold or alarmed. Once it heats up and is active again, the pale shades return.

How does a thorny devil usually walk when it crosses open ground looking for food or a mate?

In slow, jerky steps is how it moves, often freezing mid-stride with one foot still off the ground. The stop-start rhythm probably helps conceal a lizard caught in the open.

Approximately how many of its tiny insect prey can a single thorny devil lap up in one day?

About 1,000 a day is a typical estimate, taken one at a time with a short, sticky tongue. The prey is low in nutrition, so the lizard has a large stomach to hold it all.

Which popular pet lizard belongs to the same family, the Agamidae, as Australia's thorny devil?

Bearded dragon and thorny devil are both agamids, a family of more than 500 species spread across Africa, Asia and Australia. The frilled-neck lizard is another member.

Which spiky North American reptiles look much like thorny devils but are only distant relatives?

Horned lizards share the thorny devil's squat, armoured body and specialist diet, yet the two groups grew their spines separately. Only the American ones have bone inside their horns.

The thorny devil's genus name, Moloch, recalls a fearsome demon in which 17th-century epic poem?

Paradise Lost casts Moloch as a fallen angel smeared with blood, the image the zoologist had in mind when he named the lizard in 1841.

The 'horridus' in the thorny devil's scientific name is a Latin word whose first meaning is what?

Rough or bristly is the main sense of horridus, a nod to the spines, and 'dreadful' is only a secondary meaning. The animal is one of the most placid reptiles in the outback.

A thorny devil's spines are almost entirely boneless; which tough material are they made of?

Keratin forms the spines, so even the big knob on the neck is boneless. CT scans that were expected to show bone inside the spines found only two small bumps on the skull.

What are newly hatched thorny devils thought to eat before they dig their way up to the surface?

Their own eggshells seem to be the first meal: a biologist who opened two nests after hatching found no shells left. He knew of no other lizard or snake that does this.

After laying her eggs, what does a thorny devil mother do to the nest before leaving?

She seals and smooths it over, packing the tunnel so carefully that no trace of the digging remains. One mother in a field study did the whole job in the night.

Which long-legged ground bird, also called the plains turkey, is known to prey on thorny devils?

The Australian bustard was abundant where nine thorny devils were radio-tagged in 1995, and two tagged males soon vanished, most likely eaten by the big birds.

A field biologist once found a whole thorny devil in the stomach of which big Australian reptile?

Sand goanna was the answer to a mystery: a thorny devil he was studying vanished, and six months later he found that very lizard inside the monitor he had collected. Its spines had not pierced the stomach.

Thorny devils are so well camouflaged that one field biologist learned to find them by doing what?

Following their footprints over soft ground is the trick, and even that fails once the tracks enter a bush. One lizard sat unseen between two searchers standing a couple of metres apart.

How does the IUCN Red List rate the thorny devil, which ranges across most of arid Australia?

Least Concern is the official rating, though scientists remain unsure of its true numbers. Relying on a single kind of prey leaves local populations exposed when desert habitat is damaged.

Moloch, the thorny devil's genus name, was first the name of what kind of ancient figure?

A Canaanite god called Moloch, usually pictured as a hideous beast, lent his name to the genus. The lizard itself is a harmless eater of tiny insects.

Thorny devils shovel what onto their backs so that their skin can soak up extra moisture?

Damp sand can supply water when there are no puddles to stand in: the lizard rubs its body against it and the skin wicks the moisture away.

The network of tiny grooves covering a thorny devil's body channels water toward which spot?

The corners of its mouth are where the grooves end, and a gulping movement of the jaw then draws the water in. A thorny devil can gain as much as a gram of water in a single rainstorm.

Thorny devils sometimes shelter overnight inside loose tussocks of which spiky Australian grass?

Spinifex tussocks and nearby shrubs give the lizards cover at night and through the midday heat, and they retreat there when a predator comes near. The grass belongs to the genus Triodia.

Thorny devils also live in a southern scrub belt named after which many-stemmed eucalypts?

Mallee country in southern South Australia and the south-west is the lizard's second home, far from the deserts of the interior.

Thorny devils barely move during which two stretches of the Australian year?

Midsummer and midwinter are both downtime: the lizards hardly stir in January and February or in June and July. On the hottest days they retreat into shallow underground shelters.

Thorny devils walk to one regular spot each morning, away from where they sun themselves and feed, to do what?

They go there to defecate: each lizard keeps its own toilet site, marked by neat piles of glossy black pellets. It often returns to the same place several days running.

Why are thorny devils, which rely on outside heat, often run over by cars?

They bask on warm roads because, as ectotherms, they cannot make their own body heat. A road is also the easiest place for a person to spot one, since off it they blend into the ground.

Alongside bobbing up and down, which other display does a male thorny devil use to court a mate?

Leg-waving and bobbing make up the male's courtship routine. In one observed attempt, the unwilling partner threw him off her back with a quick sideways roll and walked away.

Thorny devils keep growing well into adulthood; what is the longest they are thought to live in the wild?

About 20 years is the likely limit in the wild, an estimate from a keeper whose captive lizards lived up to eight years and were still growing in their fifth.

Which term describes how thorny devils and distantly related American lizards came to look alike?

Convergent evolution means similar pressures produced the same solution twice. By body measurements, the two lookalikes are closer to each other than to their own nearer relatives.

How does a thorny devil usually catch the tiny insects that make up its entire diet?

It waits by their trails, usually close to the cover of a shrub, and laps up passers-by one at a time. Because each one is so small, it can take dozens of them a minute.

In which city was a thorny devil first exhibited, in 1840, by a famous bird artist?

London saw the strange lizard a year before it had a scientific name. The specimen came from Western Australia, and a museum zoologist formally described it in 1841.

Which bird artist, known for The Birds of Australia, first brought the thorny devil to science?

John Gould is remembered as the father of Australian bird study, yet the 1841 paper that named the lizard lists it among reptiles he discovered in Western Australia.

Many desert reptiles hunt after dark; when is the thorny devil normally out and feeding?

During daylight is when it forages, mostly in the morning and late afternoon rather than the midday heat. It depends on the sun to bring its body up to working temperature.

The thorny devil's tiny insect prey is poor food, full of hard chitin and which acid?

Formic acid and chitin make the prey poor fuel, so a thorny devil has to eat it in bulk to get enough energy.

Which egg-laying Australian mammal shares the thorny devil's diet of colony-living insects?

Echidna diets rest on the same colony insects, which makes this spiny mammal a fellow myrmecophage, the scientific word for such specialists. One is a mammal and the other a reptile.

Most reptiles bury their eggs in packed earth; thorny devil eggs instead rest in what kind of space?

An air-filled chamber holds the clutch, with nothing packed around the eggs. Two that were opened after hatching lay about 23 centimetres down and were still near 31 degrees Celsius inside.

Which misleading common name is also used for Moloch horridus, a lizard of flat desert plains?

Mountain devil is a long-standing alternative name, used in the titles of early Western Australian studies of captive animals, even though the lizard lives on plains rather than peaks.

Which part of Australia is home to the Anmatyerre people, who tell a Dreaming story about the thorny devil?

Northern Territory country is where the Anmatyerre and Alyawarr tell the story, and the lizard ranges across the Territory's arid southern half.

Film close-ups make thorny devils look monstrous; how long is a full-grown one at most?

About 20 cm, tail included, is the upper limit, and the egg-laying sex is the larger one. Outback films often show the lizard in close-up, which leaves viewers picturing a giant.

How does a thorny devil carry its tail while walking across the desert floor in search of food?

Held up high, the tail stays clear of the dirt while the lizard rocks backwards and forwards as it goes. The odd movement may confuse a predator that has spotted it in the open.