The Daintree Rainforest is home to many amazing creatures but by far the most majestic and interesting is the mighty saltwater crocodile!
These fascinating reptiles have roamed the earth for over 200 million years, outliving the dinosaurs by about 65 million years, making them the oldest surviving reptile on the planet. As if this doesn’t make them cool enough here are a few fun facts about crocodiles.
Saltwater crocodiles are the largest of all crocodile species making them the biggest reptile in the world. The males grow a lot bigger than the females reaching lengths of up to 6 meters and can weigh up to 1000kg. The females are comparatively smaller only reaching a maximum length of 3 meters. Around Cape Tribulation we have a wide array of different sized crocodiles however the largest and most well known is “Scarface” an old male who is about 5 meters long.
Most crocodiles live on average up to 60 years however many have been known to live as long as 100 years old. The oldest crocodile in captivity is called “Cassius” who is 112 years old.
Crocodiles are meat-eaters (carnivores). They have around 70 sharp teeth which are used for killing a variety of wildlife such as fish, birds, mammals and sometimes other crocodiles. However when juvenile crocodiles are born in Cape Tribulation they start off on a diet of insects, small fish and small mammals.
Breeding season for crocodiles in Cape Tribulation happens between November and March where the female lays 40 – 60 eggs in a nest made from bits of plant matter and mud normally on the edge of a river bank. The female will stay and protect the eggs until they hatch then she will guard them until they are old enough to fend for themselves.
Even though crocodiles lay many eggs only 1% of them will survive to reach adulthood. The majority will be eaten by large fish, monitor lizards and larger crocodiles. The eggs take 90 days to develop and interestingly the sex of the young crocodiles is determined by the incubation temperature. If it’s below 30C the hatchlings will be female, and above 32C they will be male.
As crocodiles are cold-blooded they rely on the sun to regulate their temperature. During the day the can often be seen on the banks of the Daintree River basking in the sun. Once they have reached their desired temperature they will regulate it by opening their mouth allowing cool air to flow over the only thin piece of skin they have which is the inside of their mouth.
Crocodiles have excellent eye-site especially at night, which is when the normally hunt. Once a torch is shined in their eyes a distinctive orange-red glow can be seen reflecting back. This makes them quite easy to see…as long as they are on the surface of the water.
Until the 1970s crocodiles in Cape Tribulation were nearly hunted to the point of extinction. Being highly sought after not only for their meat but also their skin which was used to make all sorts of luxury leather items such as handbags, belts and shoes. Crocodiles are now a protected species allowing their numbers to steadily rise back up.
Crocodiles have the strongest jaw of any animal on the planet. Muscles which close the jaw are much stronger than muscles which open the jaw. Because of that, people can use their bare hands to keep their mouth closed although this is not recommended.
Crocodiles are quite lazy hunters and are more than happy to sit and wait for food. They can control their heart rate to just 2-3 beats per minute allowing them to hold their breath for up to an hour waiting for the perfect opportunity to strike.