Goannas

There are many animals that live in a forest including reptiles like goannas (also known as monitors).

They are large lizards (up to two metres long) which rely on trees to provide them with an abundance of food, shelter and camouflage protection.

Goannas, also known as monitors, are a unique species of lizard that evolved during the Cretaceous period roughly 90 million years ago in the northern hemisphere.

Goannas migrated south during the Miocene Epoch (15 million years ago) into Africa and Australia. Due to large number of mid-sized competing carnivores in Africa, very few goannas evolved further. However, in Australia where there were fewer competing carnivores, goannas were able to evolve into 28 different species.

Goannas range in size from the 25cm long Australian Short-tailed Pygmy Monitor to the 3m long Komodo Dragon of Indonesia. One of Australia's largest goanna, which is now extinct, was the Varanus Priscus which could grow in excess of 6m long).

Goannas have large claws on their feet which make them excellent climbers, allowing them to climb trees to escape danger or to feed on bird eggs.

Goannas use a combination of predatory and scavenger behaviours when it comes to feeding. They typically hunt any land animal they can catch such as insects, lizards, snakes, rodents, small mammals, or sometimes even birds. They scavenge and eat the eggs of birds and other reptiles but also eat carrion (rotting carcasses of other animals).

Goannas mostly live on the ground and their nests are either dug into the earth which helps regulate egg temperature, or sometimes they lay their eggs inside termite mounds which provide temperature regulation, protection and a ready food source for newly hatched young.

Goannas play an important role in their ecosystems. Their varied diet helps control the populations of other animals and insects in their habitat, especially since they can both feast on animals and their eggs, and their scavenging of carrion plays critical role in the control of disease.