The sand goannas are a group of closely related Australian species which are found all across the continent and nearby islands, from tropical New Guinea in the north down to the temperate southern shore and Kangaroo and Frasier Islands. Sand goannas are earth movers extraordinaire, consumate burrowers and tunnelers who use their strong forelimbs to excavate prey. These reptilian bulldozers sniff up buried lizards, burrowing mammals, aestivating frogs, reptile eggs, salamanders, insects and the like and then unearth them in a flurry of flying dirt. They are also fast runners, however, and are also known as racehorse goannas in some areas for their speed. When sprinting, the rise up onto their hind legs and run bipedally. This turn of speed allows them to run down food as well as dig it up, while permitting them to keep ahead of any pursuit long enough to dive into a burrow, climb up a tree, or dive into water to escape. In addition to running bipedally, the sand goannas are more likely to rise onto their hind legs for other reasons than other goannas. When curious or alert, they stand up for a better look. When frightened, they will stand high to confont their antagonists. Sand goannas are restless foragers, and are quite likely the most active of any reptile.
Curiously, the sand goannas are often reluctant to bite in self defense. If the goanna cannot run or hide, it will hiss and puff up, lashing its tail. If truely frightened, they will lunge to deliver a slashing bite and then retreat. If picked up, they will scratch up the arm holding them as they try to run away and escape; if badly pressed they may turn to deliver slashing bites to hands and fingers.
The northern species of sand goanna, the yellow spotted goanna (V. panoptes, called the argus monitor in the U.S. and Europe) is one of Australia's three largest goannas. This species makes its home along rivers and lakes, in grasslands and light brushy areas. It has a white belly with a brown back covered with yellow spots. Yellow spot goannas can be found as far north as New Guinea in the areas not totally covered by jungle. Of all the sand goannas, the yellow spotted is the most likely to stand upright, often presenting a comical appearance when they pop up to look about. The yellow spot goanna is also quite likely to stand its ground if threatened, even against approaching vehicles, putting on a violent hissing display while standing tall on all fours or at a forward angle on its hind legs.
Sand goannas are tolerant of people. They can be found near major cities as well as in agricultural land. The aboriginal peoples long considered sand goannas a prime food source. Like all Australian goannas, the sand goannas are protected by law. However, many are killed on the road as they scavenge roadkill, and large numbers of young are killed by cats and dogs. The fecundity and rapid maturation of these goannas ensure they are still present in large numbers, however.
Most sand goannas are Small to Medium in size with exceptional specimens reaching Large size; the yellow spotted goanna is Medium to Large with occasional individuals reaching Huge size.