Reproduction

Heath goannas will typically begin their mating period around the longest day of the year. Mating take’s place over the next four to six weeks.

The female will lay up to 14 eggs 21 days after her last mating.

These are deposited in a termite mound during summer. It may take up to 2 days for the female to excavate a suitable chamber in the termite mound in which to deposit her eggs. Once the female lay’s her eggs termites will quickly begin to repair the damage which seals the eggs inside. If they do not she will backfill the chamber.

Over autumn and winter these eggs are maintained at a constant temperature and humidity inside the termite mound. They will hatch in the spring.

Following hatching the juvenile heath goannas dig themselves out of the mound. In some instances, the mother may also return to dig the hatchling’s out of the termite mound. The hatchlings will live within the mound to feed on the termite’s it houses for the first few days of their life.

Only one in twelve hatchlings’ will survive to one year of age.

Sexual maturity is reached at 9 years’ old. Due to the high energy demands of breeding, females typically rest a year in between breeding attempts.

Behavior

Rosenberg’s monitors are solitary animal’s only coming together for breeding season.

They are active by day. Their dark coloration assist’s with warming up in the colder region’s where they live.

Predators and Threats

Natural predators of the heath goanna include birds and snakes. Juvenile heath goannas may be preyed upon by adult monitor’s.

Introduced predators such as cats, dogs and red foxes eat heath goannas.

When threatened they tend to run along the ground unlike the similar lace monitor which will flee up a tree.

Their habitat is being destroyed including termite mounds being removed which leaves them without a suitable place to lay eggs. This habitat is also increasingly fragmented which leaves these animals at risk as they need large areas to find food.

Rosenberg’s monitors are regular road kill victims. As more roads in their habitat are sealed and speed limits increased the rate at which these animal’s die increase’s.

In parts of their range, mainly the east, they are confirmed to be declining due to these threats but the overall population trend is yet to be confirmed.

Quick facts

The heath goanna is also known as the heath monitor, Rosenberg’s goanna and Rosenberg's monitor.

Heath goannas were first described by a German herpetologist in 1957. Originally they were considered a subspecies of the sand goanna (Varanus gouldii) but in 1980 became their own species.

Studies are ongoing to determine if these reptiles are actually two unique species with some differences present in a population in the eastern states.