The Thorny Devil (Moloch horridus)

Australia is home to many unique and fascinating organisms who have adapted to the dry and humid landscape.  A critter I find eccentric is the thorny devil (Moloch horridus)  meaning a dreadful Canaanite god.  The spiny reptile was first discovered by John Gould in 1840. They are distributed throughout the arid inland of Australia, specifically on sandy soils and some stony soils.  Living in such a dry environment applies selective pressures to the wildlife.  The thorny devil has a very unique method of acquiring water from his skin.  They are able to do this because of their hygroscopic grooves in their skin which lead to the corners of its mouth.  When it rains or dew has collected on the back of the lizard, the lizard can lift its rear end and cause the water to drip into its mouth or absorb the water through capillary diffusion.  The thorny devil diet consist of only ants, making it an obligate ant specialist, in one meal it can consume over 1500-2000 ants. 

How does this small slow moving lizard protect itself from scavenging monitors and lizards?  It uses its second head.  The thorny devil has a 'false head' on the back of its neck which is used when the lizard is in danger.  It tucks its head in between its forelegs and hopefully the predator will bite its spiny 'false head'.  The thorny devil can also inflate itself like a puffer fish and use its spine to prevent itself from being bitten or eaten.  

Adult females are larger than adult males; females can range from 80-110 mm from snout to vent and weight from 30-90 grams.  Males are all under 100 mm and rarely weigh more than 50 grams.  The females usually lay 3-10 eggs during the spring-summer months and are buried 30 cm deep underground.  Some have been found to live for more than 20 years.  

Although they are poorly studied because of they are difficult to be found, they are magnificent creatures who have adapted uniquely to the unforgiving, arid inland of Australian.  Make sure to keep your eyes open to spot their tracks.

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