Estuarine crocodile, Indo-Pacific Crocodile, Marine crocodile, Sea Crocodile, ‘Saltie’
Saltwater crocodiles are the largest living reptile on the planet. They can reach over 7m long, weigh 1000 kg, and live for over 100 years. They are brown, grey and green in colour with differing patterns and large smooth scales covering their body. They have a laterally compressed tail to help them swim fast and propel them vertically out of the water. Their tail also has scutes or spines running down the length that help regulate temperature. Their 66 teeth poke out the sides of their mouth on the top and bottom jaw when it is closed, differentiating crocodiles from alligators. Crocodiles are excellent in the water, they have webbed feet, and their eyes, ears and nostrils are on the top of their head to help them hunt undetected by ambushing their prey. Their eyes help them to find their prey underwater, as each eye has a third transparent eyelid called a nictitating membrane that acts as a pair of goggles.
Saltwater crocodiles are strictly carnivorous and will eat a variety or prey: Fish, turtles and medium-sized mammals are the most common prey but cows, kangaroos, water buffalo and humans are all possible prey items.. Juvenile crocodiles will eat smaller prey including fish, frogs and insects.
They are found in estuaries, creeks, billabongs and lagoons. They can be found in either fresh or saltwater habitats, and have been recorded spending decent amounts of time at sea.
Saltwater Crocodiles are found along the coastal regions of the top end of Australia, from Broome in WA along the coast and all the way down to Rockhampton, QLD. It is also found up through south-east Asia, all the way to the east coast of India.
Saltwater crocodiles have been around for 200 million years because they are such a large apex predator, preying on whatever comes into contact with their river system. They have the strongest bite force of any animal in the world, 5 times that of a human, and therefore it is very important to read the signs around the water and stay away when you are in crocodile territory. A 2m crocodile is capable of dragging a prey item the size of an adult male into the water, but the larger the prey; the more effort it takes to eat. Saltwater crocodiles do not have flexible tongues and jaws, and to break up their food they perform the death roll, and thrash their prey around until smaller pieces fall off and they can be swallowed. During this process, some teeth may be lost or broken, but that does not phase the crocodile because they are able to regrow teeth which takes 6 months. They have 66 teeth to help them grab prey and break it apart so they are very important, and every 2 years they replace all of their teeth to keep them sharp. Along the top of the tail, the crocodile has scutes that are filled with blood to absorb heat and pump it to the rest of the body so that they can warm up quickly and not have to leave the water.
Although feared as a ‘man-eater’, Saltwater crocs were almost hunted widely for meat and leather in the 1950s and 1960s. By the end of the 1960s, overhunting had led to the species disappearing almost completely across its entire range, with local extinctions in different parts of south-east Asia.
Between the late 60s and early 70s Saltwater Crocodiles were named a fully protected species across WA, NT and QLD. Today, their numbers have recovered to the point that they are considered ‘Least Concern.’ That said, some local surveys have shown that numbers, although up, are not quite as high as initially anticipated. This is especially important to point out now because in recent times, there have been increasing calls to allow hunting again. Hunting does occur now to a small degree, but croc are usually only trapped, relocated or culled in situations where they are considered serious threats to humans and/or livestock.