Saltwater Crocodile

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Saltwater Crocodile Conservation status: Least concern (LR/lc)
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Sauropsida Order: Crocodilia Family: Crocodylidae Subfamily: Crocodylinae Genus: Crocodylus Species: C. porosus
Binomial name
Crocodylus porosus (Schneider, 1801)
Range of the Saltwater Crocodile in black

The saltwater or estuarine crocodile (Crocodylus porosus) is the largest of all existing reptiles, and is often said to be the most dangerous to humans. It is found in suitable habitat throughout Southeast Asia and northern Australasia. Saltwater crocodiles are known in the Northern Territory of Australia as 'salties'. The Alligator Rivers are misnamed after the resemblance of the 'saltie' to alligators as compared to freshwater crocodiles, which also inhabit the Northern Territory.

[edit] Diet

This saltwater crocodile is an opportunistic predator capable of taking animals up to the size of a water buffalo, either in the water or on dry land. Juveniles are restricted to smaller items such as insects, amphibians, crustaceans, small reptiles and fish. The larger the animal grows, the greater the variety of items that it includes in the diet, although relatively small prey still make up the majority of the diet even in adults. Saltwater crocodiles can take monkeys, wild boar, dingos, domestic livestock, water buffalo, sharks [1] and sometimes humans. Generally very lethargic – a trait which helps it survive months at a time without food – it typically loiters in the water or basks in the sun through much of the day, usually preferring to hunt at night. It is, however, capable of moving with astonishing speed when required, able to cover 10m from a standing start significantly faster than a race horse, especially from the edge of the water, where both legs and tail are utilsed for propulsion. As an ambush predator, it usually waits for its prey to get close to the water's edge before striking without warning and using its great strength to drag the animal back into the water where it is usually drowned (although if there is more than one crocodile about, it may simply be dismembered). It is an immensely powerful animal, having the strength to break a large animal's legs with its tail, drag a fully grown water buffalo into a river, or crush a full-grown bovid's skull between its jaws. In its most deadly attack, nicknamed the "Death Roll," it grabs onto the animal and rolls powerfully, which normally snaps the neck or just rips it apart. In one case in Northern Australia in 1939, a prize Suffolk stallion weighing over 1 tonne (2,205 lb) was killed, apparently in under a minute, by a large crocodile. It is said that saltwater crocodiles are large enough and strong enough to prey on Great White Sharks, although this is mostly myth due to the fact that the two species would virtually never come into contact with on another (Great Whites prefer colder waters, although occasionally may be found in the crocodiles range around Cairns, Australia)

[edit] Size

Adult male saltwater crocodiles are typically 4.8 meters to 5 metres(15.4 to 16.6 ft) long, weigh around 770 kg (1697 lb). Although larger individuals may surpass 6 metres (20 ft) or 7 metres (23 ft) in length and weigh more than 1500 kg (3707 lb). In fact this species is capable of growing to sizes up to 8 metres (27 feet) or even 9 metres (30 feet). [2] Females are much smaller than males, with typical female body lengths in the range of 2.5–3 metres. One of the largest crocodile ever recorded was 8 metres 64cm (28ft 4 inches) shot by Krystina Pawloski (School teacher, later conservationist) on the Norman River in northern Queensland, Australia in 1957. A cast of this Crocodile can be seen in northern Queensland and is quite the shock indeed. It is said that a saltwater crocodile can be just as powerful as a full grown great white shark. Their bony plates are as hard as rocks. The largest "official" crocodile alive right now lives in Orissa, India and has officially been measured to be 23 feet in length. Larger crocodiles may exist still, but no verifiable evidence has been found.

[edit] Habitat and Range

Saltwater Crocodile sunning itself at Corroboree in the Northern Territory of Australia.

Saltwater crocodiles generally spend the tropical wet season in freshwater swamps and rivers, moving downstream to estuaries in the dry season, and sometimes travelling far out to sea. Crocodiles compete fiercely with each other for territory, with dominant males in particular occupying the most eligible stretches of freshwater creeks and streams. Junior crocodiles are thus forced into the more marginal river systems and sometimes into the ocean. This explains the large distribution of the animal (ranging from the east coast of India to northern Australia) as well as it being found in odd places on occasion (such as the Sea of Japan, for instance). Saltwater crocodile speed underwater can be 12 to 15 miles per hour in short bursts, but when cruising can go 2 to 3 miles. Saltwater crocodiles are severely depleted in numbers throughout the vast majority of their range, with sightings in areas such as Thailand, Cambodia, Laos and Vietnam becoming extremely rare. With that said, it is also the least likely of crocodilians to become extinct due to it's wide distribution and almost pre-colonial population sizes in Northern Australia and Papua New Guinea. In India this crocodile is extremely rare in most areas but is very common in the north eastern part of the country (mainly Orissa and the Sunderbans). The population is sporadic in Indonesia and Malaysia with some areas harboring large populations (Borneo for example) and others with very small, "at risk" populations (the Philippines). The saltwater crocodile is also present in limited portions of the South Pacific, with a substantially large population in the Solomon Islands and very small populations in Vanuatu (where the population officially only stands at 3!) and Palau (possibly rebounding). Rouge crocodiles have historically been found throughout much of the South Pacific due to their seafaring abilities, with sightings of lone individuals on Fiji, Iwo Jima, New Caledonia and even far north in the Sea of Japan! Though these animals have since disappeared and no breeding populations were present. Hawaiian folklore and native history suggests that this species MAY have been present on the island many centuries ago, though no hard evidence exists and the lack of prey may disprove the theory. Saltwater crocodiles prevailed, suprisingly far from their normal range, off the coast of Africa on the Seychelles Islands all the way up until Europeans arrived. This was once believed to be a population of Nile Crocodiles but has since been proven to as Crocodylus Porosus.

[edit] Intelligence

Dr. Adam Britton, a researcher with Wildlife Management International, has been studying crocodilian intelligence. In so doing, he has composed a collection of Australian saltwater crocodile calls, and associated them with behaviors. His position is that, while crocodilian brains are much smaller than that of mammals (as low as 0.05% in the saltwater crocodile), they are capable of learning tasks with very little conditioning. He also infers that the crocodile calls hint at a deeper language ability than currently accepted. The saltwater crocodile is probably the smartest reptile in the world.

[edit] See also

• Crocodile attacks

[edit] References

• Crocodile Specialist Group (1996). Crocodylus porosus. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 09 May 2006.

[edit] External links

• Recent Crocodile Attacks in Australia
• Crocodylus porosus (Schneider, 1801), by Adam Britton from the Crocodilian Species List.
• Saltwater crocodile calls from Dr. Britton's crocodilians.com site
• Brief discussion from Dr. Britton and others discussing dromaeosaurid intelligence