Crocodile

The crocodiles are stealthy predators and insight fear around the world. A crocodile lives a semi-aquatic lifestyle and hunts in water, sitting and waiting to ambush their prey. Being reptiles, they are cold-blooded, egg laying animals. Crocodiles are found mostly in tropical and sub-tropical climates in Asia, Australia, Africa and the Americas.

A crocodile is a solidly built animal with short limbs and large, flattened mouths. Their eyes, ears and nostrils are positioned on the top of their heads which allows them to keep almost their entire body underwater while they stalk their prey.

They are an ancient group of animals and had their greatest diversity way back in the Cretaceous between 145-66 million years ago. At present there are 23 different species of crocodiles that fall into the order Crocodilia which includes three families – Alligatoridae (alligators and caiman), Crocodylidae (true crocodiles) and Gavialidae (gharial).

Hunting and diet

Crocodiles hunt by stealthily stalking their prey from water. Some species ambush their prey as they drink from the water’s edge or bath. Many species are able to kill and eat large mammals such as zebras, wildebeests and humans. Once it has caught its prey, a crocodile will then drag it into the water and drown it. It eats its prey by biting off large chunks of meat and swallows them whole. Other species, such as the Chinese alligator and gharial, feed primarily on fish or invertebrates.

Parental care

Similar to birds, crocodiles and alligators are surprisingly caring parents. Both the males and females play a role in raising their young by protecting their nest and hatchlings. Certain species help their babies to hatch from their eggs by gingerly opening the shells with their teeth. When chicks of the American alligator hatch, mothers carefully carry all of her newborns from the nest to nearby water, one or two at a time.

‘True’ crocodiles

There are 14 species of ‘true’ crocodiles from the family Crocodylidae. They are found in tropical regions of the Americas, Asia, Australia and Africa. Most species live in freshwater habitats but some are found in salt water. Many species of crocodiles are currently endangered.

The saltwater crocodile (Crocodylus porosus) is the largest of all currently living reptiles and is found in this family. It can grow more than 7 m (23 ft.) long and weigh more than 1000 kg (2200 lbs.). Unfortunately there are no longer any crocodiles this size because they grow slowly and all the largest animals have been hunted.

Alligators and Caimans

The two species of alligators and five species of caimans make up to family Alligatoridae. They live in freshwater habitats such as lakes and rivers and can be distinguished from crocodiles by their wider U-shaped snouts. Excluding the Chinese alligator, the alligators and caimans are new world animals, found in the Americas and the Caribbean. The American alligator is found in the USA along the Gulf Coast and the caimans range from Mexico, through the Caribbean and into South America.

The alligators and caimans range in size from 1.2-5 m (4-16 ft.), the black caiman (Melanosuchus niger) being the largest species in this family. The American alligator is much larger than the Chinese alligator which only grows to an average length of 1.5 m (5 ft.).

Gharial

The gharial is the sole remaining species from the family Gavialidae. It is found in northern India through to Burma and is the second largest species of crocodile behind the saltwater crocodile. It feeds on fish and has a very narrow snout with sharp, interlocking teeth which is handy for catching its prey.


Interesting facts

  • Crocodiles are more closely related to birds than any other group of animals.
  • As with turtles, the gender of crocodiles is determined by the temperature that their eggs are incubated at.

Last edited: 17 December 2015

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