Tree Goanna

Victorian Conservation Status: Secure

Tree Goannas enjoy secure conservation status. They are widespread and have adapted to many different environments.

Did you know?

Tree Goannas

• are Victoria’s largest lizards, they weigh up to 20 kg and are 1.5–2 m long
• lay their eggs in termite mounds
• use their forked tongues to detect prey
• are carnivores, they eat insects, lizards, mammals, nestling birds and carrion

Where they live

Tree Goannas are found along the east coast of Australia. They live in a range of habitats including open forest and coastal plains.

Amazing Tree Goannas

Tree Goannas, also known as Lace Monitors, are powerful tree-climbers and fierce predators of small animals. They have strong, sturdy limbs and large claws to help them climb, and sharp teeth to catch and hold their prey.

Being reptiles, Tree Goannas are unable to moderate their own body temperature, instead relying on the sun and the ambient temperature. They are sluggish in winter, feeding little and rarely leaving their burrows. On warm days they bask in the sun to warm up. Their dark colour helps them absorb heat.

These lizards belong to a group called monitors. Monitors detect their prey with a special sense organ in the roof of their mouths called Jacobson’s organ. By flicking their long forked tongue out of their mouths, they transmit scent molecules to this organ. They forage for food in trees and on the ground.

Male Tree Goannas fight over females in behaviour known as ritual combat. They rise up on their hindlimbs and try to overpower one another, sometimes rolling over and over while wrestling. The losing male usually receives a nasty bite, while the winning male mates with the female.

Female Tree Goannas lay 4–14 leathery-shelled eggs in termite mounds. After 6–8 weeks, females may return to their eggs to excavate the hatchlings. They receive no further care from their mother.