Twenty of the worlds 58 species of Goannas or Monitor Lizards as
they are known elsewhere in the world. The largest, and most famous
goanna species is the Komodo Dragon of Indonesia. One species of goanna
in Australia has become extinct since European settlement. The name
Goanna is an Aboriginal word and the Goanna features heavily in Aboriginal
dream time stories.
Appearance and Characteristics
They range in size from just 15cms to 1.5 meters excluding the tail
length. They have a flattened body, a tail ready to strike at enemies,
stout limbs, long digits and sharp claws. Goannas have a long neck
with loose skin under the throat which sags in some species causing
it to look like the neck is bigger than the head. They will often
puff out this skin when threatened to intimidate would be predators.
They have sharp teeth that are often described as shark like.
Mating behaviors differ amongst the goanna species, but generally
they will produce 3 - 25 eggs which they lay in the soil. They will
loosely cover their "clutch" with soil. As with most lizards,
they do not actively guard their eggs. The hatchlings break free after
incubating, and are independent from birth. In captivity, incubation
has taken up to year when kept at a steady temperature of 30 degrees
celsius. Incubation times, like clutch sizes vary amongst species.
Diet and Habitat
Goannas find their food by searching widely across the landscape,
catching animals by stalking or digging them out of shelters and nests.
They primarily prey on birds, snakes and seek the eggs of both. They
will also opt for an easy meal and feed on carrion. Using their long
forked tongues which they flick in and out, they pick up scent in
the air and on the ground. Goannas then "read" these scents
with a special organ in the roof of the mouth, much like a snake does.
Found in all regions of Australia, the Goanna is an excellent climber,
and a strong swimmer. Goannas are largely terrestrial and digs its
own burrow system but it will readily take refuge in a tree if a burrow
is not nearby.