Saltwater Crocodile (Crocodylus porosus): Facts and Habitat

Appearance

Adults are dark olive, gray-green or almost black above, with paler tan or gray patches, and a white to yellowish belly. Hatchlings and juveniles are much brighter: pale yellow or tan with bold black stripes and spots on the body and tail. These markings fade over several years.

The head is large and heavy. The snout is broad for a crocodile, roughly twice as long as it is wide at the base, and a pair of low ridges runs from the eyes toward the nostrils. Compared with most other crocodiles, the saltwater crocodile has few or no enlarged bony scales (scutes) on the back of the neck, which is one way experts recognize it. As in all true crocodiles, the large fourth tooth of the lower jaw stays visible when the mouth is closed. Learn the other differences in alligator vs crocodile.

How big do saltwater crocodiles get?

No other crocodilian shows such a big difference between the sexes. Males can weigh four to five times as much as females and may be almost twice as long.

The largest crocodile measured alive was Lolong, a male caught in Bunawan, Agusan del Sur, in the Philippines in 2011. He measured 6.17 m (20 ft 3 in) and weighed about 1,075 kg (2,370 lb), and he died in captivity in 2013. Cassius, a male captured in the Northern Territory in 1984 and kept on Green Island in Queensland, measured 5.48 m (18 ft) and was recognized for years as the largest crocodile in captivity before his death in November 2024.

Old reports of crocodiles 8 to 10 m (26 to 33 ft) long have never been confirmed. When the skulls of such legendary animals have been examined, they point to crocodiles of 6 to 7 m (20 to 23 ft) at most. For a comparison with other species, see how big do crocodiles get.

Habitat and range

Saltwater crocodiles live in tidal rivers, estuaries, mangrove swamps, coastal lagoons and freshwater swamps and billabongs (seasonal river pools), and they often swim along coasts and between islands. They are the most widespread crocodile on Earth. The range runs from the east coast of India, Sri Lanka and the Sundarbans of India and Bangladesh through Myanmar, Malaysia, Indonesia, Brunei and the Philippines to New Guinea, northern Australia, Palau, the Solomon Islands and Vanuatu.

In Australia they occur from around Broome in Western Australia across the Northern Territory and down the Queensland coast to around Gladstone. Many crocodiles move upstream into fresh water during the tropical wet season and back toward estuaries in the dry season. Dominant males hold the best stretches of river, which pushes younger animals into poorer habitat and sometimes out to sea, one reason the species has reached so many islands.

The species tolerates sea water thanks to salt-excreting glands on its tongue. Satellite tracking in Queensland showed crocodiles riding coastal currents for hundreds of kilometers, and barnacles are sometimes found on their scales after long periods at sea. Read more in can crocodiles live in salt water?

Diet and hunting

The saltwater crocodile is a carnivore that will eat almost any animal it can overpower. Hatchlings catch insects, shrimp, small crabs, frogs and small fish. As they grow, they take larger fish, mud crabs, turtles, snakes, water birds and mammals. Big males can kill wild pigs, deer, kangaroos, water buffalo and cattle, and they also scavenge carcasses.

It is a classic ambush hunter. A crocodile lies almost completely submerged with only its eyes, ears and nostrils above the surface, drifts close to prey at the water’s edge and then lunges with an explosive sideways strike. Large prey is dragged underwater and drowned, and pieces are torn off by shaking or by spinning the body, the so-called death roll. In a 2012 study of all living crocodilians, a 4.59 m (15 ft) saltwater crocodile produced the strongest bite force ever measured in an animal, 16,414 newtons (3,690 lbf). See how strong is a crocodile bite?

Because a crocodile is cold-blooded and burns little energy while resting, it can go weeks or even months without a meal. Most hunting happens at night.

Behavior

Saltwater crocodiles spend much of the day basking on mud banks or resting in the water, and they are more active and spend more time in the water during the warm months. They are the most territorial of all crocodilians. Adult males defend stretches of river and drive off rival males with head-slaps on the water, growls and fights, and young animals start to disperse from the nursery area at less than a year old and become territorial themselves by about 2.5 years.

Like other crocodilians, they communicate with sounds. Hatchlings chirp inside the egg and call to their mother, juveniles give distress calls, and adults make low growls and bellows. Tracking studies have shown a strong homing instinct: crocodiles moved hundreds of kilometers by helicopter in the Northern Territory have returned to where they were caught within weeks.

Reproduction and life cycle

Females usually begin breeding at around 10 to 14 years old and about 2.2 m (7 ft) long. Males mature later, at about 16 years and 3.3 m (11 ft). In Australia, courtship takes place in the late dry season and eggs are laid during the wet season, from about November to March.

The female builds a mound nest of mud and plant material, usually near a freshwater swamp or a tidal river bank, and lays about 40 to 60 hard-shelled eggs, occasionally up to 90. Rotting vegetation helps keep the eggs warm, and incubation lasts around 80 to 90 days. As in all crocodilians, the temperature inside the nest decides the sex of the young: nests at around 31 to 32 °C (88 to 90 °F) produce mostly males, while cooler and hotter nests produce mostly females.

The mother guards the nest. When the young call from inside their eggs, she digs them out, sometimes gently cracks eggs in her mouth, and carries the hatchlings, about 25 to 30 cm (10 to 12 in) long and 70 g (2.5 oz), to the water. She stays near them for several weeks to months. Even so, losses are heavy. Floods drown many nests, and hatchlings are eaten by fish such as barramundi, monitor lizards, birds, pigs and larger crocodiles. Estimates suggest only about 1 percent of hatchlings survive to adulthood.

Lifespan

A saltwater crocodile that survives its first few years can live for decades. Wild adults are commonly estimated to live 50 to 70 years or more, but exact ages are hard to prove because crocodiles are rarely followed from hatching to death. Growth slows greatly after maturity, so large size does not reveal age precisely. Claims of individuals living past 100 years exist, notably for Cassius, but none has been verified. Learn more in how long do crocodiles live?

Conservation status and recovery

The IUCN Red List classes the saltwater crocodile as Least Concern, in an assessment published in 2021. That does not mean the species is safe everywhere. Unregulated hunting for its skin, the most valuable of any crocodilian, devastated populations across its range in the 20th century, especially between the 1940s and the 1970s. The northern Australian population is thought to have fallen by about 95 percent by 1971.

Australia then gave the species full protection: Western Australia in 1970, the Northern Territory in 1971 and Queensland in 1974. Numbers have since recovered dramatically, and Australia now holds well over 100,000 wild saltwater crocodiles, most of them in the Northern Territory. Controlled harvesting of wild eggs for crocodile farms gives landowners an incentive to keep wetland habitat, and international trade is regulated under CITES.

Elsewhere the picture is mixed. The species has vanished or nearly vanished from the wild in Thailand, Vietnam and Cambodia and was wiped out in the Seychelles about two centuries ago. Populations in Sri Lanka, Palau and parts of Indonesia contain few large adults, a sign of continued killing. Habitat loss, illegal hunting and conflict with people remain the main threats, while protected areas such as Bhitarkanika in Odisha, India, show how well populations can recover.

Danger to people

The saltwater crocodile is one of the few animals that sometimes treats humans as prey, and it is considered one of the two most dangerous crocodilians, with the Nile crocodile. In Australia, where attacks are carefully recorded, there are on average about one or two fatal attacks a year. Data elsewhere are patchy, and many attacks in remote parts of Indonesia, Timor-Leste, Malaysia and the Solomon Islands are probably never reported.

Most attacks happen when people swim, wade, fish or wash at the water’s edge in crocodile habitat. Wildlife agencies advise obeying warning signs, never swimming where saltwater crocodiles may live and keeping well back from the water’s edge. For real figures and context, see are saltwater crocodiles dangerous?

Myths and facts

Myth: saltwater crocodiles live only in the sea. In fact they spend much of their lives in rivers, swamps and billabongs, sometimes far inland, and the females nest beside fresh or brackish water. The name refers to their tolerance of salt water, not to where they must live.

Myth: crocodiles are slow and clumsy. On land they usually move slowly, but a strike from the water happens in a fraction of a second, and they can swim strongly with their tails.

Myth: there are crocodiles 9 or 10 m long. No such animal has ever been measured. The largest reliably measured saltwater crocodiles were a little over 6 m (20 ft).