The Saltwater Crocodile is the world’s largest living reptile. Males average a length of five metres and weigh approximately 450 kgs. Females are much smaller, reaching up to three metres and weighing 150 kgs. Their olive-green, leathery skin is armoured with bony oval plates, known as “scutes”. Their tails are made of solid muscle that propel them through the water.

Habitat

In Australia, Saltwater Crocodiles inhabit the northern reaches of the continent, across Western Australia, Northern Territory and Queensland. In the wet season they live in freshwater swamps and rivers. In the dry, they move downstream to estuaries, sometimes travelling far out to sea. The reptiles are extremely territorial and compete with each other for prime real estate along the banks of rivers and streams. The animals are also found in South East Asia, New Guinea and Indonesia.

Diet

While younger Saltwater Crocodiles are restricted to a diet of smaller reptiles, crustaceans and fish, adults feed on a number of larger species, including water buffalo, turtles, snakes and even humans (although crocodiles have killed less than 30 people since 1971).

Behaviour

Saltwater Crocodiles are opportunistic predators. They often lie in wait for their victims, just below the surface of the water, and without warning, quickly strike. They will often kill their prey with one snap of their powerful jaws. If not, they will drown it with a “death roll’, dragging it down under the surface. What they don’t eat straight away, they’ll store underwater until later. To communicate, crocodiles use physical displays, grunting sounds and chemical signals.

Reproduction

Breeding occurs during the wet season. Females reach maturity at age 12, males later, at 16 years. During nesting, the female makes a nest in muddy vegetation and lays between 40 to 60 eggs. For 12 weeks she protects the incubating eggs and then helps the new hatchlings to reach the water. She’ll stand guard over her young until they disperse over the following weeks. In the wild, juvenile crocodiles have many predators and it’s estimated that only one percent of hatchlings survive to adulthood.

Lifespan

The average lifespan of a crocodile is 70 years, but some are known to live well over a hundred.

Threats & Conservation Status

Until 1971, Saltwater Crocodiles were freely hunted in the Northern Territory, decimating their numbers. Today they’re protected and it’s illegal to injure or harm them. There’s an estimated population of 100,00 crocodiles that live in Australia.

More Amazing Facts

• Crocodiles have their own form of air conditioning – while basking in the sun they can stop their brains from overheating by opening their mouths, allowing moisture to evaporate.
• Crocodiles can slow their heartbeat down to two beats per minute, allowing them to hold their breath for up to an hour underwater.
• Crocodiles can control the flow of blood through their bodies by “shunting” blood flow to essential organs, such as the heart, brain and muscles, and restricting flow to non-essential areas, such as the intestines.
• Crocodiles have no vocal chords, so growls are made by snorting air through the back of the throat or their nostrils.
• The largest Australian “Saltie” on record was more than 8.5 meters long. The beast was killed in 1958 by a schoolteacher, who later became a conservationist.
• A crocodile’s mouth contains around 65 teeth.
• More people die from bee stings each year than from crocodile attacks