The estuarine crocodile is the world’s largest living croc.

Meaning of scientific name
Crocodylus porosus = 'pored crocodile'.

Statistics
Body Length: usually 4.2-4.8m, although specimens of over 7m have been recorded. Weight: Male: generally 408-520kg, but have been known to exceed 1000kg.

Physical description
A large-headed crocodile, with heavy jaws. Ridges run from the eye sockets to the snout, and are very prominent in older animals. Males are bigger than females.

Distribution
They are found from eastern India and Bangladesh through Southeast Asia to Papua New Guinea and Australia. They occur as far east as the Solomon Islands and Vanuatu.

Habitat
They are typically found in brackish water in tropical estuaries, rivers and swamps. They congregate in the upper reaches of tidal rivers in the dry season and move into freshwater swamps in the wet season. Sometimes seen in the open sea, as they can travel long distances (up to 1000 km) by swimming and drifting.

Diet
Estuarine crocodiles mostly feed on small prey such as fish, crustaceans and small terrestrial vertebrates. Adult crocodiles can tackle larger prey, including humans. They are not fussy eaters, and almost any mammal at the water’s edge will be attacked.

Behaviour
The estuarine crocodile deals with large vertebrate prey by overpowering, drowning and finally dismembering them. Crocodiles have a valve to seal off the mouth from the throat. They can thus open their mouth underwater without inhaling water. However, a crocodile can’t eat its prey underwater - swallowing would get water into the stomach and lungs. The croc therefore either drags the prey onto land, or sits up and raises its head above the water to swallow. When swimming, the tail provides the propulsive force. Legs are either held flat against the body (for streamlining) or sometimes held out (to prevent rolling), but are not involved in swimming. Sometimes they jump or leap out of the water. They start the leap from a stationary position at the water surface. This is more effective in deeper water, so the crocodile can position its body at a steep angle as the tail propels it upwards.

Reproduction
Males engage in noisy bouts of fighting prior to mating at the start of the wet season. Females build a large mound of vegetation and lay 40 to 62 eggs in a chamber within it. The mother will stand guard over the mound for about 100 days. Upon hatching, the hatchlings squeal, prompting the female to dig them out and carry them to the water. The hatchlings then live in creche groups for about 8 months, guarded by the adults.

Conservation status
They are not listed by the IUCN.

Notes
The estuarine crocodile is the species responsible for most crocodile attacks on people. They often attack boats (which they may regard as rivals or as prey). They are most aggressive towards people in the breeding season. Even so, more people die from bee stings each year than from croc attacks. Because the estuarine crocodile has few osteoderms (bony plates, also called scutes) on its belly, the value of its hide is higher than that of other crocodiles. Its numbers in Australia were greatly reduced by hunters until the 1970s, when hunting was regulated. Crocodile farms now supply the bulk of the skins for the leather trade.

Records
The estuarine crocodile is the world’s largest living croc.