The Sand Monitor is one of the 25 or so species of Goanna (or Monitor Lizard) in Australia.  The scientific name of this animal is Varanus Gouldii.  Other common names are the Sand Goanna, Gould’s Monitor and the Racehorse Goanna.

Some reptile experts classify Rosenberg’s Goanna as being in the same species.

Size

The Sand Monitor is a large Goanna.  Exceptional individuals may approach 2 metres (6 feet) in length although the average is less than this.  A typical weight for an adult Sand Monitor is about three and a half Kilograms.

This lizard has long claws and sharp teeth.  A goanna bite can easily turn septic because of the high level of bacteria in its mouth.  Recent research suggests that in addition to the bacteria, some Goannas also produce some venom.

Territoriality

Diet

Sand Monitors are mostly carnivorous, eating what they can catch and also carrion.  When they are young, their main food will often be insects and smaller types of reptile.

As they get bigger they eat bigger things.  In the northern parts of their range they eat a lot of Crocodile eggs.

They are also potentially a major predator of Rabbits.

Threats

Foxes and feral Cats are major predators of young Goannas.  In the areas that extensive Fox baiting has been carried out, there appear to be more baby Goannas.

Predation of the baby Goannas by Foxes is one of the things preventing the Goannas building up in numbers sufficiently to be a major predator of Rabbits.  On Kangaroo Island where there are no Foxes Rosenberg’s Goanna was able to wipe out the Rabbits.

Cane Toads are a major threat to Goannas and to other native predators. When this poisonous amphibian moves into an area there tends to be a rapid decline in the numbers of predators.  However, the predators appear to be adapting in various ways to the presence of the Cane Toad and their numbers are building up again.

Speed

Goannas can run fast.  While running quickly they often run on their hind legs, not all four as they normally move.  A large Goanna can run a hundred yards about twice as fast as a fit Human can.  However, this is their limit.  Because of the way their blood circulates they need to rest after a run. 

If you are chasing a Goanna, as long as you can keep it in sight for the first hundred metres and see where it hides after that you can catch it.  But I definitely do not suggest doing this.  Apart from being legally protected, a Goanna is not something you want to be bitten by.

Sources

http://australian-animals.net/goanna.htm

http://www.smuggled.com/BriBar15.htm

http://www.smuggled.com/goabur1.htm

http://www.abc.net.au/nature/island/ep5/locals/1.htm

http://eprints.utas.edu.au/2193/