What do they look like? Mertens’ Water Monitor or “Goannas” grow to a total length of about 1m. Unlike other goannas, a water monitor will not run, but rather slide into the water when disturbed or threatened. They are dark brown to black in colour with many small cream or yellow spots. The underbelly is white to pale yellow, with grey patterns on the throat and chest.
Where do they live? Mertens’ Water Monitors is an aquatic lizard that basks on rocks and branches near water. It drops into water when disturbed and can stay underwater for long periods. They are found along small streams and creeks in the tropical north of Australia from Western Australia to Queensland.
What do they eat? Like most reptiles Mertens’ Water Monitors are considered to be opportunistic predators. They feed on fish, crabs, frogs and carrion.
Behaviour: Mertens’ Water Monitors are excellent swimmers and can stay under water for several minutes. They have an excellent sense of smell and may dig up prey when foraging. They are accomplished climbers and can be seen climbing on rocks or trees near water.
Reproduction: They lay eggs in a burrow constructed in the ground. Egg laying usually takes place in the early dry season. The hatchlings enter the water immediately. Active termite mounds are often a good place for a female to deposit her eggs.
Threats: Unfortunately the introduction and subsequent spreading of Cane Toad populations in Australia poses a threat to these animals. Deforestation is also reducing populations.
Conservation Status: Vulnerable