Saltwater Crocodile

Saltwater Crocodile

Saltwater Crocodile information

The Saltwater crocodile, Crocodylus porosus, is the largest now living crocodile in the world and also the largest of all reptiles. It is found in Northern Australia and Southeast Asia and can traverse long distances at sea. It was once present along the eastern coast of Africa as well.  

Saltwater Crocodile taxonomy
















Crocodylus porosus

Saltwater Crocodile conservation status

Crocodylus porosus is listed as Least Concern on the IUCN Red List of Threatened Species.

Australia is home to a thriving population of Saltwater crocodiles spread along its northern coast in the Northern Territory, Western Australia, and Queensland. The population is believed to comprise 100,000 to 150,000 adults. The species is also widespread in Papua New Guinea where it is found in virtually all rivers, estuaries and mangroves.

The situation for the Saltwater crocodile in other parts of its range is much more grim. It did for instance disappear from the Mekong River in the 1980s and is now on the brink of extinction in many South-East Asian countries.  

Saltwater crocodile range

The Saltwater crocodile range includes the following countries: Australia, Bangladesh, Brunei, Myanmar / Burma, Cambodia, China, India (including the Andaman Islands), Indonesia, Malaysia, Palau (Caroline Islands) , Papua New Guinea, Philippines, Singapore, Sri Lanka, Solomon Islands, Thailand, Vanuatu (Banks Islands), and Vietnam.

Since this species can travel long distances at sea it sometimes show up along the coasts of other countries and has for instance been reported from the Sea of Japan, Fiji and Iwo Jima. This ability explains its wide distribution and why it is present on such remote islands as Vanuatu, Palau and the Solomon Islands. Historically, you could also find Crocodylus porosus along the eastern coast of Africa and on the Seychelles Islands. These crocodiles were long assumed to be Nile crocodiles but later research unveiled that they were in fact Saltwater crocodiles.  

Saltwater crocodile habitat

As the name implies, the Saltwater crocodile has a high salt tolerance and can be found in the ocean and in coastal habitats. It is however commonly found in fresh water and brackish environments as well, such as rivers and wetlands. It usually spends the wet season in freshwater rivers, streams and swamps and before migrating downstream as water becomes more and more scarce with the onset of the dry season. The dry season is typically spent in estuaries, but some crocs head out to sea for shorter or longer periods of time. Dominant males will chase off all other males from their territory and submissive males are often forced to either withdraw into marginal parts of the river system or traverse the ocean in search for a less crowded piece of land.    

Saltwater Crocodile size and appearance

How large is a saltwater crocodile?
Most adult male Saltwater crocodiles are 4-5 m long (13-17 ft), but occasional specimens do exceed this length. (See below). A 5 m (17 ft) male typically weighs 400-500 kg (880-1100 lbs).

The females are much smaller than the males and typically attain a length of no more than 2.5-3 m (8-10 ft).  

How large is the biggest crocodile?
The saltwater crocodile is the largest now living crocodilian species (based on confirmed measurements), it is also has the largest mass of all now living reptiles.  

The skin of a diseased Saltwater crocodile measured 20 feet (6.1 m), but since crocodile skin tends to shrink slightly after being removed from the carcass the living length of this crocodile was probably somewhere around 20.7 ft (6.3 m). According to estimations, its weight was probably well over 1,200 kg (2,600 lb) but this is of course impossible to verify when you only have the skin.

The skull of a crocodile shot in Orissa, India have been claimed to come from a 25 ft (7.6 m) specimen, but according to scholarly examination of the skull the animal was probably no longer than 23 ft (7 metres). Numerous rumours about Saltwater crocodiles exceeding 9 m (30 ft) in length do circulate, but none of them has been confirmed. A 10 m (33 ft) crocodile is for instance said to have been killed in the Bay of Bengal in the 1840s, but its scull indicate a length of less than 6.6 m (22 ft).  

A male saltwater crocodile living in the Bhitarkanika Park in Orissa, India is believed to be roughly 7.5 metres (25 ft) long and weigh around 2,000 kilograms (4,400 lb). Trapping and measuring such a large and feisty animal is however an immense undertaking so the accuracy of these estimations has not been confirmed.

The largest female Saltwater crocodile on record measured about 14 ft (4.2 m).

It is not unfeasible to assume that Saltwater crocodiles used to be larger in the past before widespread crocodile hunting and habitat destruction commenced. With today’s restoration and protection of suitable habitats in certain areas and the decrease in poaching, we might very well see a return of such giants.  

What does a Saltwater crocodile look like?
The Saltwater crocodile has a large head with a heavy set of jaws. Its muzzle is longer than that of the Mugger crocodile (Crocodylus palustris) with which it shares part of its habitat. A pair of ridges runs from the eye orbits along the centre of the snout and these ridges will become increasingly distinct as the animal grows older. 

Juvenile Saltwater crocodiles are usually pale and adorned with black stripes and spots on body and tail. They will retain this coloration for several years, but it will grow increasingly pale as the animal ages.

Making out the true coloration of an adult saltwater crocodile is actually quite difficult, since they tend to be covered in mud and algae. Mature males are dark with some lighter areas and a cream colored belly. Dark bands and stripes decorate the lower flanks.

Saltwater mobility

Saltwater crocodiles can reach a pace of 15 to 18 mph (24-29 km/h) when swimming, but only in short bursts. When cruising, they normally swim no faster than 2-3 mph (3-5 km/h).

On land, it can carry out explosive charges and outrun a human.      

Saltwater Crocodile feeding and diet

Saltwater crocodiles normally hunt at night, spending the day resting in the sun or in the warm water.

The adult Saltwater crocodile is an apex predator capable of catching prey on dry land as well as in the water. Saltwater crocs are for instance known to prey on sharks, mudcrabs, birds, snakes, wild boar, monkey, kangaroos, wallabies, goanna lizards, and dingos.  They can also attack and kill humans, pets and domestic livestock.

The largest prey taken by Saltwater crocodiles are water buffalos and gaurs which can weigh over a ton. Overcoming such prey is normally only attempted by really large males. Despite being capable of overpowering virtually any animal that ventures close enough, comparatively small prey make up an important part of the diet even for big crocodiles.  

Juvenile Saltwater crocodiles feed on animals such as insects, crustaceans, amphibians, fish and small reptiles.

Saltwater Crocodile breeding

Females reach sexual maturity when they are 2.2-2.5 m (7.2-8.2 ft) in length, which normally happens at an age of 10-12 years. Males will not be ready to breed until they are around 3.2 m (10.5 ft), which means that it is uncommon for males younger than 16 years to reproduce.  

Saltwater crocodiles normally form breeding territories in freshwater areas such as tidal rivers and creeks. A mound nest is built from mud and available vegetation to protect the eggs from extreme temperatures and drought, hide them from predators, and decrease the risk of them being flooded. The mounds are usually built between the months of November and March during the wet season but the exact season varies throughout the species range.

The female can lay anywhere from 25 to 90 eggs in the nest, with the average female laying 40-60 eggs. The exact length of the incubation time is temperature dependant but most batches hatch after 80-90 days. The lower the temperature the longer the incubation. Nest temperature will also determine the sex of the offspring with the highest percentage of males being produced around 31.6°C. A lower or higher temperature will yield more females.  

When the female hear the characteristic chirping sounds produced by hatching crocs, she will help digging them out of the mound nest. Some females have also been observed helping their offspring reach the water.

Eggs and hatchlings are preyed on by animals such as turtles, goanna lizards and Crocodylus johnsoni, and humans and the invasive species they bring can also be bad news for Saltwater crocodile eggs. The main cause of embryo mortality is however not predatory animals but floods. When it comes to juvenile crocs, quite a few of them are eaten by territorial males.

Saltwater crocodiles grow up in freshwater environments but as they become older they will be eaten or chased away from the territory by larger males. This force them to either seek out marginal, less desirable parts of the river system or venture into saltwater. 

Saltwater Crocodile facts

Saltwater Crocodile facts # 1
The Saltwater crocodile can travel over a thousand kilometres by sea but needs dry land to reproduce. Barnacles have been found growing on the scales of some crocs, indicating that they have spent extended periods of time in marine conditions.  

Saltwater Crocodile facts # 2
The brain of a saltwater crocodile can comprise as little as 0.05% of the body weight.

Saltwater Crocodile facts # 3
Because of its broad body and the low number of armor plates on the neck, the Saltwater crocodile was earlier believed by some to be an alligator rather than a true crocodile. It is sometimes referred to as Gator in Australia and the Alligator Rivers are named after this species.

Read more Saltwater Crocodile facts

Saltwater Crocodile lifespan

The Saltwater crocodile can live for 75-100 years.


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