Merten's water monitor

Physical features

• The Mertens’s water monitor has a slender, forked tongue like a snake.

• It can grow to about a meter or more in length (over three feet).

• It is dark brown to olive-green with light colored spots. Its underbelly is yellow and it can have grey patterns on its chest and throat.

• It has a thick, laterally (from the sides) flattened tail which provides most of the propulsion while swimming, similar to a crocodile.

• It has nostrils on the top of its head, which allows it to remain partially submerged while looking for prey, similar to a crocodile. These nostril valves shut tightly when the monitor dives underwater.

Diet: Carnivore

• Wild – Fish, frogs, small mammals, insects, crabs, and reptile eggs

• Zoo – Fish, mice, crayfish, crickets

Reproduction

• Mertens’s water monitors breed during Australia’s dry season and lay eggs in nesting chambers filled with leaf litter.

• Incubation takes 6-10 months.

• A female can lay up to 11 eggs in a single clutch.

• Hatchlings immediately enter the water and swim away.

Interpretive Information

• The Mertens’s water monitor folds its legs against its body to swim very quickly like a crocodile.

• Like most monitors, this species uses its tongue to track the scent of prey along long distances and detect buried clutches of eggs.

• Research has shown that the two tips of their forked tongues detect chemicals in a stereo fashion. This provides highly accurate scent tracking.

• Australian Aboriginal folklore is full of legends about monitor lizards. These animals represent powerful and mystical elements of nature for them.

Updated September 2024