Australian Saltwater Crocodiles
Australia has two types of crocodiles, the freshwater crocodile, which mainly eats fish, and is not considered a danger to man, and the saltwater crocodile, a true meat eater.
Crocodiles are true dinasaurs, and have changed little in the evolutionary stakes over millions of years.
The Saltwater Crocodile…or ‘Salty’ as Australians refer to it, is found as far down as Broome on the western coastline, and Rockhampton on the eastern coastline. It inhabits the surrounding islands off the coastline also, and has been known to swim as far as 1,000 klms (620 miles) by sea to reach it’s destination.
In times of extreme drought, it has also been known to travel across land many klms to find a safe waterhole to ensure it’s survival. Although it prefers salt water, it can survive quite readily in fresh water.
It’s diet consists of fish and small mamals and birds, which venture too close or unwittingly near the waters edge.
The Salty spends most of it’s time sleeping, and in summer avoids the hot sun, hunting mostly during the cooler hours of the day.
When hunting for food, the usual procedure is to expose only it’s eyes and nostrils above the waterline until prey is spotted, then sinking without a ripple, swims effortlessly underwater and attacks it’s prey from underneath the water, lunging upwards. Or moving with amazing agility and speed, will spring from the water and up onto the bank. Razor sharp teeth, and astounding jaw pressure ensures a firm grip on it’s prey, the salty then drags it’s hapless victim into the water and procedes to go into the ‘death roll’, rolling over and over and in the case of larger prey, such as buffalo or cattle, dragging it’s prey underwater where it consequently drowns.
In order to eat it’s food, it’s impossible for the Salty to eat underwater, and food must be consumed on top of the water. A careful examination of the above photograph, you will notice a flap of skin at the back of the throat, this acts as a safety valve, closing whilst the mouth is open under water. This prevents it from drowning.
Saltwater Crocodiles have been recorded as big as 7 metres in length (23 feet). Although the most common length of a fully grown male crocodile would average 5 to 6 metres (18 to 20 feet).
It is impossible to judge accurately the age of a croc, unless a bone sample is obtained. Their bones have ‘growth rings’ much the same as trees. Salties mature sexually at around 16 years of age for males and 12 to 14 years of age for females.
Crocodiles are ‘mound builders’, the female carefully builds a nest of leaves and twigs and soft soil, just above the water level, and not far from the river. She lays a clutch of around 50 eggs, and guards them fiercely during the 80 day incubation period. When the first of the hatchlings begin their unique grunting sounds, she uncovers the rest of the eggs, carefully carries the hatchlings to the waters edge and breaks open any unhatched eggs to aid the remaining babies. They remain close to the female for protection for several months. The mortality rate is very high amongst young crocs, older crocs take their toll on numbers and only about 1% of hatchlings survive in the wild.
Crocodiles do not have sexual chromosones, the sex of the hatchlings depend entirely on the temperature of the mound. For males to be born, the mound must be kept at a constant 31.6 degrees C (88.88 F) any variation up or down ensures that females are born.
Since protection of the species began in 1971 there has seen a rapid rise in croc population, there are few deaths from encounters with these creatures. Australians are very well aware and educated in the ways of the croc.
The deaths that have occured could well have been avoided had the proper care and attention to watching out for crocs been adhered to.
Only 27 deaths have been recorded since 1971 from croc attacks. In almost all cases death occured whilst they swimming in crocodile country.
Saltwater Crocodiles live a long life by animal standards, the average would be around 70 years old, but have they been known to live to over 100 years old.