Get the facts about crocodiles before you visit Australia
Australian saltwater crocodiles are by far the most dangerous creatures in Australia. These predatory reptiles are aggressive, territorial, deceptive, sneaky and unpredictable. Get the facts about Australia’s longest surviving prehistoric predator.
The Saltwater Crocodile can be found all across Northern Australia, and throughout the Solomon Islands and Vanuatu, across Papua New Guinea, Indonesia, the Philippines, Malaysia, all the way to Vietnam, Cambodia, Thailand and India, and everywhere in between.
In Australia, crocodiles are often called ‘salties’, and populate the brackish and freshwater regions of northern Australia.
of Crocodile warning signs
Crocodiles are living dinosaurs
Crocodiles first appeared over 240 million years ago during the Mesozoic Era. Living up to 80 years old, and growing anywhere from three metres to seven metres in length, this incredible carnivore has been on top of the food chain for 100 million years.
Protected animals after near extinction
Throughout the last century, saltwater crocodiles were hunted almost to extinction. In 1971 they became a protected species which has resulted in their numbers growing drastically. It is now believed that there are around 200,000 ‘salties’ roaming the ‘Top End’ in Northern Australia.
Predators and opportunists
Classic opportunistic predators, these crocodiles lurk patiently beneath the surface near the water’s edge, waiting for potential prey to stop for a drink of water. Without warning, they surge from the water with a thrash of their powerful tails, grasp their victim and drag it into the water, holding it under until the animal drowns. Although they are known to attack humans, they are reported to kill on average less than one human per year.
Brackish water habitats
The name saltwater crocodile is misleading. Salties live in the brackish waters along the coastlines but often found in freshwater rivers, swamps and billabongs, and often many hundred kilometres inland. Crocodiles are capable of propelling their body to leap out of the murky waters to attack their prey.
The unique cooling system
Like most reptiles, crocodiles are cold-blooded and cannot produce their own heat resulting in them hibernating or going dormant in the cooler season. Whilst they prefer the heat and live in tropical climates, they cannot generate body sweat, so to cool off, they sit along the river bank with their mouths open. They sweat through their mouths!
A human can apply 100 pounds of pressure per square inch with their jaw, whereas a crocodile can apply up to 5,000 pounds of pressure per square inch with their jaw. It allows them to feed on mammals, birds and fish and eat when opportunity presents. They have been known to attack humans, however the risk is minimal.
Excellent swimmers, crocodiles have often been spotted miles out at sea. Crocodiles can swim up to 32 kilometres per hour and hold their breath for up to an hour underwater. Often they lie in wait for an opportunity to take out their prey. Despite this, crocodiles cannot eat underwater. They are equipped with valves that prevent water going into their throats which allow them to open their mouths underwater without drowning. A crocodile will need to rise to the surface or return to land, to swallow.
The ‘Death Roll’ ends it all
Crocodiles have been known to deliver a death roll when capturing their prey. This roll is designed to throw large beasts off balance to enable them to be dragged into water easily. When their prey puts up a fight, or it is a larger prey, they will roll underwater disorientating the prey, making it easier for him to consume.
Caution should always be followed when entering Crocodile habitats!
Crocodiles in the Northern Territory, Australia
The population of saltwater crocs in Australia is thought to be as high as 200,000. The highest concentration has been recorded around the Mary, Adelaide and Alligator river systems in the Northern Territory.
The average density of crocodiles across tropical Australian rivers is five crocs per kilometre, but the Mary River in the Northern Territory can average as many as 20 crocs per kilometre.
See Crocodiles in their natural habitat in the Top End
It’s well known that saltwater crocodiles lurk around most Top End waterways so swimming on any beach or waterways in the Northern Territory is not an option. Most visitors are curious about these predatory beasts and want to see saltwater crocodiles whilst visiting the Top End!
Choose an experience that suits your fear factor.
- Crocosaurus Cove in the heart of Darwin city has one of the largest reptile collections in Australia. Are you ready to brave Australia’s only crocodile dive in the Cage of Death?
- Take a ‘Jumping crocodile cruise‘ on the Adelaide River. Crocodiles literally jump out of the water to take food offered by the tour guides. You will learn all about the predatory behaviours of these crocodiles.
- Enjoy a Corroboree Billabong Wetland Cruise and see some of the Territory’s extraordinary bird-life, stunning waterlilies and monster crocodiles from the safety of a boat. The guides are extremely knowledgeable and share a wealth of information about the birds, crocodiles and their habitats.
- Visit Sweetheart. Sweetheart was once the dominant male crocodile living in Sweets Lookout billabong, just outside Darwin in the Northern Territory and is now a popular exhibit in the Northern Territory Museum.
Caution is key to longevity
Living with these risks, as northern Australians we know not to swim in the rivers, creeks or billabongs and we rarely swim in the ocean.
It’s been noted that some fishermen brave the crocodile infested rivers for a chance at catching a barramundi … it really is only a matter of time! We have learned very quickly that these predators are everywhere, they are quick … and silent!
Just because you can’t see them,
doesn’t mean they’re not there!
The territorial nature of the males requires every mature male to have its own territory.
Raising a family of crocs
Breeding and raising of the young saltwater crocodiles actually happens in freshwater areas between November and March.
The location of the crocodile nests is thought to be an indicator of how much rain is expected during the upcoming wet season. Its not fail-proof though, sometimes the crocodiles get it wrong and nests are flooded when the rains come, destroying the eggs.
The female lays 40 – 60 eggs in a nest made from plant debris, leaves and mud and guards the nest preventing it from drying out by splashing it with water during the incubation period. The eggs take 90 days to incubate.
Interestingly the sex of the young saltwater crocodiles is determined by the incubation temperature.
Below 30oC the hatchlings will be female, and above 32oC will produce males.
When the eggs are about to hatch they make chirping sounds inside their eggshells calling mum to help dig them out of the nest.
She carries the hatchlings to the water’s edge in her mouth and watches over them until they are able to look after themselves.
Despite mum’s care, less than 1% of the hatchlings will reach maturity. The hatchlings are preyed on by turtles and goannas and the juveniles are often eaten by mature territorial males.
The territorial behaviour of the male saltwater crocodiles forces the young crocodiles out of the region in which they have been raised. They go further afield to find unoccupied territory for themselves.
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Be careful along the water’s edge as crocodiles are capable of ambushing you in the blink of an eye. When visiting northern Australia, don’t swim in the rivers, creeks or billabongs. Please don’t take unnecessary risks.
References: Northern Territory Tourism Central