Goanna Monitor Lizard

“Goanna” is the term used to describe any Australian Monitor Lizards from the Varanus genus, as well as other species which are found in South Asia. There are about 30 known species of Monitor Lizard, or Goanna, 25 of which are commonly found all over Australia, apart from Tasmania (although this is not surprising considering their favoured conditions).

Goanna are carnivorous reptiles and are regularly found in mythology and Australian folklore as lizard-warriors and man-eating beasts, which is far from the truth. Smaller species of Goanna will survive on insects, mice and birds (if they come across one that doesn’t get away), whereas the larger species will eat larger mammals, other lizards, snakes, larger rodents, birds and eggs. Recently, one Goanna (identified as a Perentie – the largest species) was actually seen eating a small kangaroo – eating the meat in chunks, but this is almost un-heard of. This is because, contrary to belief and although their size leads people to believe they could eat most mammals, Goanna actually eat their food whole, therefore it is rare that you will come across instances like the kangaroo incident mentioned above.

Goannas have one of the largest ranges in size through-out their species of all lizards. The smallest Monitor Lizard species is the short-tailed monitor, which reaches just 20cm in length and is often spotted basking on people’s walls and garden paths, whereas the largest species, as said above, the Perentie is enormous – reaching and sometimes exceeding 2 meters in length. Goanna’s are found in trees as well as on the ground – some of the species are in fact mainly arboreal, sometimes completely – even the larger species may try to climb trees in search of food. All Goanna eat carrion which is small enough to eat and are attracted to the smell of rotting meat. This is partly why they are blamed for killing farmer’s sheep: if a sheep dies for any reason, a monitor will attempt to eat it, purely because it’s an easy meal.

Like most lizards and reptiles, Goanna’s lay eggs, which they sometimes lay in termite mounds. While this may seem like a silly idea, it is actually incredibly clever: the termite mounds provide perfect incubation, and when the eggs hatch the young offspring can feed on the termites – not so silly after all. Usually Goannas will lay between 7 and 35 eggs, though this will depend on the species, and the age of the Goanna. Goanna generally live for 15 to 20 years, both in the wild and captivity, providing they are kept in the best possible condition and space.

Again, contrary to belief these lizards will not attack adult humans, unless provoked to the point where they feel they have to for their safety. Even if they attack, they will not kill adult humans (certainly not on purpose). There have been rare cases where a starving monitor lizard has eaten very small children, but it is unlikely you are going to leave a baby or toddler lying in the middle of Australia for an hour or so anyway, right? However, generally speaking, this lizard species is extremely intimidated by humans and will try its best to get away, in fact, if it is startled and frightened to a certain extent, it may actually raise itself onto its hind legs and run as fast as it can in this way for a few meters, before it drops onto all fours and runs normally. They are surprisingly fast for such big creatures and swift movers, and they can out-run many people due to their complex maneuvers. If a Monitor is threatened and cannot get away easily, it will rear up to it’s tallest height, push out flaps of skin around its neck, head and throat, and make a loud, disturbing hissing noise, which is a warning for you to get away.

Although gentle, wonderful creatures by nature, due to their size and popularity, some people enjoy seeking them out and antagonising them. These people and by-standers will almost always get bitten, attacked or knocked out by the Goanna’s incredibly powerful tail. People don’t seem to take on board that if these creatures wanted to, they could kill a human in a matter of minutes, without breaking a sweat. Although those who do try to tease and annoy them will find this out the hard way. Also, recent research has begun to suggest that Goanna have oral toxin glands, and are in fact venomous, but there is still not enough known about the toxicity of the venom or the dose that would have to be injected before it was fatal. Although this will depend on the species.