Estuarine Crocodile - Salt Water crocodile

Salt water
or
Estuarine
CROCODILE

Two types of Crocodiles are found in Australia,
The freshwater Croc and the Salt Water (Estuarine) Croc
The salt water Croc is the biggest reptile in the world

Salt vs Fresh
1) Fresh water crocodiles have a narrower snout
2) Fresh water crocodiles and are smaller than the "Saltys"
3) Fresh water crocodiles can only live in fresh or slight salty water, whilst the saltwater crocodile can survive in both types of water.
4) Saltys lay eggs in nests of vegetation whilst freshwater crocs lay their eggs in sand.
5) Fresh water crocs teeth are shaped more like needles for piercing fish.
6) Saltwater Crocs reproduce in the WET season while Freshwater Crocs reproduce in the DRY season

Location
Found along Australia's northern coast and up to 200km inland, from Rockhampton on Queenslands "Capricorn Coast" to Broome in Western Australia. (see map)

Habitat
As the name suggests these crocodiles are mainly found in Estuaries where tidal rivers meet the sea. This watery habitat is often mangrove lined They can also be found sometimes in the open sea or inland in freshwater swamps and billabongs

Description
The worlds largest reptile the "Salty" has a broad "stubby" snout with cone shaped teeth. Its average length is 4 meters but males 6 to 7 meters have been reported. Saltwater Crocs have rows of bony scales on their neck and back There colouring is mainly greyish brown with brown and yellow sides. Their rear feet are webbed to aid with swimming. It is thought that they live up to 70 to 100 years Their clear eyelids enable them to see underwater.

Feeding
The feeding strategy of a salt water croc is to wait close to the water's edge and pounce upon its victim in the blink of an eye . The usual prey of younger crocs is smaller animals such as fishes and crustaceans crabs insects etc Adults can also attack and eat larger animals by overpowering and then drowning them, (the teeth are designed more for holding) eg fish, turtles, birds, reptiles and mammals (dingoes wallabies) even domestic cattle and people After the prey is dead the croc will break the prey up into smaller pieces by violent flicking of the head to snap or break bones or twisting and rolling the body Larger crocs will also take carrion (dead animals) if hungry.

Breeding
As already mentioned nesting takes place in the wet season after males fight for the females. The female croc builds a nesting mound of vegetation, mud and soil (about 2 meters long)and lays between 40 and 60 leathery eggs inside the mound. This mound raises the eggs above the water level hopefully saving them from damage She then guards the nest for 3 months until the young crocs using a special egg tooth on the top of their snout break free from their eggs. Carefully carrying her young in her mouth she takes them to the water. In the wild only about 1% survive to be adult crocodiles.

Boy or Girl at Birth?
This sounds amazing but it is true. The temperature at which the egg is kept determines the sex of the baby crocodile ! If the egg is kept at 31.6 degrees Celsius it will be male. Hotter or colder it will be a female !

Thermoregulating Behaviour
Often you will see a saltwater crocodile gaping (its mouth open). This enables the Croc to cool down, as a lot of their time is spent thermoregulating (maintaining their body temperature between 30 and 32 degrees Celsius) as Crocs are cold blooded (ie their blood temperature is effected by the weather around them)

Status of Estuarine Crocs in Australia
In 1970 Estuarine Crocodile become a protected species because prior to this intense hunting had drastically reduced numbers Though croc numbers have increased since 1970 many crocs are still lost, drowned in fishing nets etc. Dangerous large crocs are relocated away from human contact if necessary

LINKS .......Estuarine Crocodiles by Dr Adam Britton
......................... Hartleys Crocodile Adventures
......................... Australian Saltwater Crocodile