Distribution: Northern Australia and Eastern Queensland
Habitat: Estuaries, swamps
Description: Crocodiles are grey to golden-tan to almost black with a lighter-coloured belly. The head is large with a heavy snout. The crocodile’s back is covered with ridges that provide protective armour and act to conceal the crocodile’s movement below the surface of the water.
Diet: Crocodiles are carnivores and eat crustaceans, fish and other vertebrates including large animals—like sheep and cattle and sometimes humans—which they kill by drowning or by the sheer strength of the closing pressure of their jaws.
In the wild: After mating, the female makes a large nesting mound of vegetation, mud and soil, away from the water’s edge and lays between 40 and 62 hard-shelled eggs. The temperature of the mound determines the sex of the crocodile. If less than 32 degrees Celsius the hatchling will be female, between 32 and 33 degrees Celsius it will be a male. The female protects the nest during the 100 day incubation period and then digs out the hatchlings when they start to call inside the nest. She then carries them in her mouth down to the water.
Threats: Prior to its protection in the 1970s, the Estuarine Crocodile was hunted intensely and was listed as a threatened species. After years of legal protection, their numbers have increased and their threatened status has been removed.
At Perth Zoo: Perth Zoo has one Estuarine Crocodile in the Australian Wetlands. We call him Simmo. Simmo is between 50 and 70 years old, 4.7 m long and weighs about 500 kg. The crocodile presentation is held at the exhibit Monday–Sunday at 12.00pm.
Did you know? The Estuarine Crocodile is the world’s largest living reptile. Although occasionally seen in the open ocean, this species is mostly estuarine (meaning it tends to remain in the estuaries where river meets ocean).