What is the difference between a goanna and a monitor lizard

Goannas have even been blamed for the death of sheep by farmers, though most likely erroneously, as goannas are also eaters of carrion and are attracted to rotting meat.

Not all goannas are gargantuan. Pygmy goannas may be smaller than a man's arm. The smallest of these, the short-tailed monitor Varanus brevicuda reaches only 20 cm in length. They survive on smaller prey such as insects and mice. Most goannas are dark in coloration, whites, greys, blacks and greens featuring prominently. Many desert dwelling species also feature yellow-red tones. Camouflage ranges from bands and stripes to splotches, speckles and circles, and can change as the creature matures; juveniles sometimes being brighter than adults.

Like most lizards, goannas lay eggs. Most lay eggs in a nest or burrow, but some species lay their eggs inside termite mounds.

This offers protection and incubation, additionally the termites may provide a meal for the young as they hatch. Unlike other species of lizards, goannas do not have the ability to regrow limbs or tails. Goannas are found throughout most of Australia and manage to persist in a variety of environments. Most species are terrestrial, or ground dwelling. Prominent among these is the Sand goanna Varanus gouldii — also known as the ground goanna or Gould's goanna , the most common of all goannas.

They are often found in close proximity to a burrow or den, which may be a hollow log, or if in the plains a dug burrow which can be up to a metre three feet deep. They may even take over rabbit warrens. The far end of the burrow is often close to the surface, so if the entrance is blocked off by a predator, or a collapse the goanna just needs to break through a thin layer of soil to be free. As well as sandy plains, some goannas live in rocky outcrops and cliffs, often having special adaptations that aid their survival.

The spiny-tailed goanna Varanus acantharus of Northern Australia, has blunt spines on its tail that make it virtually immovable from the rockface if in danger. While some terrestrial goannas may occasionally climb trees or outcrops, there are plenty of primarily arboreal species. The lace monitor Varanus varius is probably the best-known amongst these, but is not the most common. Goannas mostly live on the ground and dig holes for nests or burrows to protect eggs from predators and provide a constant temperature for embryo development.

The Heath Monitor also known as Rosenberg's Monitor and Lace Monitor will dig holes into the side of termite mounds to lay their eggs. This is clever as the termites then rebuild the nest around the eggs, keeping them safe and at a constant temperature.

Unlike Heath Monitors, mother Lace Monitors will return when the young hatch, to help dig them out. Several species, including the Perentie, hibernate during the coldest months from about May to August. Ridge-tailed Monitors get their name from the raised and pointed scales on their tails, which they wedge into rock crevices, making it harder for predators to pull them out.

Goannas are surprisingly good climbers. In fact, Lace Monitors are known as Tree Goannas and are thought to eat more bird eggs than other goanna species. The Sand Goanna is also known as the Racehorse Goanna. While they may appear slow, goannas are fast runners and will sprint short distances on their hind legs — often to the safety of water or a tree.

Water Monitors are excellent swimmers and can stay underwater for several minutes hunting for food such as fish, frogs, crabs or shrimps. In northern Australia crocodile eggs are a favourite food. A Rosenberg's Monitor using its tongue at Scottsdale Reserve. Photo Brett Peden. Goannas can run and climb quite efficiently, and will normally run from danger. Just like snakes, goannas swallow their prey whole, and, like the Komodo dragon, it is reported that its saliva is a festering cocktail of bacteria, making its bite lethal.

Skinks come in a wide variety of colours and are typified by their thin, shiny, almost snake-like appearance. They are relatively small and feed predominantly on insects. It can grow to over two metres. Perenties live in the dry regions of inland Australia and particularly like rocky country. Perenties look, eat and live just like I described above for goannas in general. Something I didn't mention is hibernation.

Perenties and other goannas hibernate during the cold time of the year, from about May to August. Despite its huge the size the Perentie is a rather shy lizard, and it is not a common sight. But some people get lucky. Here is a page that has some beautiful photos of a wild Perentie. Water monitors Varanus salvator are the second biggest lizards in the world, but they aren't native to Australia. The Australian water monitors are smaller.

The uncommon Mitchell Water Monitor is smaller, about two and a half feet 70 centimetres. Both live in northern Australia near creeks, swamps, lagoons and other bodies of water. Water monitors are excellent swimmers and can stay under water for several minutes.

Most of their food comes from the water - fish, frogs, crabs, shrimps and similar - but they also find some on land, like reptile eggs and insects.

Unlike other goannas a water monitor will not run, but rather slide into the water when disturbed or threatened. Another name sometimes used for them is Racehorse Goanna.

There are several species and subspecies, and there is some taxonomic confusion, so I'll just keep it simple and throw them all together as Sand Monitors. These large goannas are plentiful just about anywhere, except for the extreme south and south east of Australia.

Sand monitors are the most terrestrial of all goannas. They only climb trees to escape trouble. Sand monitors are equipped with longer legs and bigger feet than most goannas and are particularly good diggers. They seem to get a lot of their food from below the ground. And here is an interesting tidbit of information regarding the goannas in the north.