Thorny Devil rescue & release
Someone surrendered a Thorny Devil 10 days ago to Queensland Parks and Wildlife Service office in Mackay. They contacted us here at Ethabuka Reserve to see if we could release it.
The Thorny Devil (Moloch horridus) is a small desert lizard found across arid and semi-arid Australia. Growing up to 20 cm long, it's known for its spiky body, its strange walk and ability to channel water through grooves in its skin. Despite its fearsome appearance, the Thorny Devil is a harmless ant eater.
At a glance
Scientific name: Moloch horridus
Common names: Thorny Devil, Mountain Devil, Thorny Lizard, Moloch
Length: Up to 20 cm
Diet: Ants
Habitat: Arid and semi-arid Australia
Lifespan: Up to 20 years
Conservation status: Least Concern
Active period: Diurnal (day-active)
The Thorny Devil is marred with a wicked common name, and its Latin species name Moloch horridus doesn’t seem much better. It's the sole species in the genus Moloch and is actually a harmless, slow-moving ant-eater. Horridus means bristly, referring to the reptile’s erect stance.
The Thorny Devil is a diurnal (day-active) reptile that can grow up to 20 cm long.
The species holds cultural importance for many Aboriginal groups – for example, the Anmatyerre/Alyawarr people of the Northern Territory have a dreaming story that surrounds it. 1
The Thorny Devil is actually one of the most placid reptiles you could encounter in the Australian outback.
Where do Thorny Devils live?
Thorny Devils are endemic to (only found in) Australia. Their range covers most of arid Australia – large parts of Western Australia, the southern half of the Northern Territory, South Australia and western Queensland.
They live in dry sand country, spinifex grasslands and scrub. 2
Are Thorny Devils endangered?
It may be a well-known species, but scientists are still somewhat unsure about its distribution and population size. Although The International Union for the Conservation of Nature (IUCN) has graded it as ‘Of least concern’, 3 Thorny Devils depend heavily on healthy ant populations and intact desert habitats. Changes to fire regimes, invasive species and habitat degradation may affect local populations.
Image Information
Thorny Devil. Photo Ben Parkhurst.
Environmental adaptations
How do Thorny Devils drink?
Thorny Devils have a unique way of drinking – they can absorb water using capillary action through their skin by simply standing in a puddle. Think of your skin being able to suck water into your body like a sponge.
Also, the spikes that give the Thorny Devil its scary appearance, and which were once thought to act only as a defense mechanism, actually help channel rain or condensation into its mouth – a useful adaptation for a desert living lizard.
They’re also thought to bury themselves in sand, in extreme circumstances, to draw moisture from it. 4
What do Thorny Devils eat?
Thorny Devils only eat ants. In the morning and late afternoon they'll find a feeding site that has cover and wait for ant prey to pass in trails that they can lap up with their short, sticky tongues. Ants are relatively low in nutritional value, but devils have large stomachs and in one day an individual can eat a thousand ants! 5
This diet seems to suit them just fine: they can live up to 20 years old in the wild.
How do Thorny Devils behave?
Head-bobbing and leg-waving is how a male Thorny Devil attracts a mate. Courtship complete, the female then lays 3 to 10 eggs in a chamber burrowed 30 cm deep in the soil. Depending on the temperature, the eggs hatch after three to four months.
Young start eating almost immediately.
Image Information
A tiny juvenile Thorny Devil. Photo Ben Parkhurst.
Are Thorny Devils threatened?
Natural predators include Goannas and predatory birds such as the Brown Falcon. Being entirely reliant on ant populations, the Thorny Devil is vulnerable to habitat loss and disturbance.
Being ectotherms (which get their body heat from external sources) they’re at risk of being run over while basking on warm roads.
How they avoid predators
Being covered in thorny spines makes these lizards difficult to eat. The Thorny Devil also sports a ‘pretend’ head on the back of its neck, which is thought to warn off predators.
Their other defense is camouflage. Easiest to spot on roads, they can blend in beautifully with their sandy, arid habitat and can be difficult to spot even when nearby.
Devils can change colour to blend into their surrounds, appearing mostly grey, red, orange or yellow.
The Thorny Devil walk
Their gait is also remarkable: tail lifted, they walk along with slow, jerky movements backwards and forwards. This might be a defense mechanism to confuse predators when they’re spotted in the open. This video was filmed at our Eurardy Reserve in mid-west, Western Australia.
What’s Bush Heritage doing?
Thorny Devils are found on our Charles Darwin, Hamelin and Eurardy reserves in Western Australia, as well as Pilungah and Ethabuka in Queensland and Bon Bon Station in the arid rangelands of South Australia.
They’re also found in the Birriliburu Indigenous Protected Area where we partner with the Martu people to support work such as fauna surveys and reinstating traditional fire patterns.
Image Information
Thorny Devil. Photo Ben Parkhurst.
Protecting ecosystems and wildlife across the continent
Contribute to a future where Australia's extraordinary natural landscapes are protected and unique species, such as the Thorny Devil, have suitable habitat. Bush Heritage protects important ecosystems and supports wildlife across the continent.
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