Crocodiles in Australia
There are two kinds of crocodile in Australia.
They live in the hot north of Australia.
They eat meat.
Crocodile scales have become thick skin.
There are two kinds of crocodile in Australia: the Estuarine, a saltwater crocodile and Johnsons, a freshwater crocodile. Both are found in the hot, tropical northern part of the continent.
The Estuarine crocodile, while it can live in salt water, is able to go quite far up river into fresh water. It is one of the most dangerous of all the crocodile family, being the biggest and heaviest. It grows to between 4 and 7 metres long.
The Johnsons crocodile lives mostly in freshwater, but can also live in salt water. It grows up to 3 metres long. It is considered to be dangerous even though it is not known for attacking humans.
Crocodiles have long narrow snouts, and the 4th tooth of the lower jaw is outside when the mouth is closed. Their scales have modified (changed over centuries) to form thick tough skin.
Unlike other reptiles, crocodiles have four sections in their hearts, like mammals and birds have. Their long, flattened tail moves from side to side as they swim through the water, with their legs by their sides. Their movement in the water is powered by their tail. The legs are short with webbed toes, five on the front legs and four on the back legs. On land, crocodiles can run very quickly, lifting their bodies up off the ground.
All crocodilians have eyes and nostrils are on the top part of the head so that they can lie in the water almost completely hidden from view.
Crocodiles have very strong jaws. They do not chew their food. They swallow it in large chunks. In the stomach the food is broken down. They feed on a large variety of prey such as small mammals, birds and even domestic livestock.
Crocodiles grab their prey and move to deep water, where they roll over to drown the animal.
They can leap high out of the water to reach their prey if necessary.
After mating, the female crocodile lays about 50-80 eggs in a nest she makes near a river bank. She covers the nest with leaves and other vegetation. The rotting vegetation keeps the eggs warm and the nest moist. The female stays and guards the nest for 90 days until the eggs hatch.
When the hatching babies call out, their mother opens up the nest and carries her babies to the water, where they immediately start feeding on frogs, shrimps and insects. About half will not survive the first year.
Crocodilians communicate with each other with sounds that they make by forcing air through a voice box in the throat. The young call to the adults when they are in danger and make lots of noise while they are being fed. Adults make loud, low roars to each other. If they are threatened, adult crododiles hiss and growl. When a male and a female mate, they purr softly.
They also use poses and movements to communicate. Raising the jaw off the ground is one such movement.
Acknowledge this source in your bibliography like this:
Sydenham, Shirley & Thomas, Ron. Australian Crocodiles. [Online] www.kidcyber.com.au (2012)
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