Crocodiles are large aquatic reptiles that live in tropical regions of Africa, Asia, the Americas and Australia.
They are members of the order Crocodilia, which also includes caimans, gharials and alligators.
There are 14 species of crocodiles.
All crocodiles are semiaquatic and tend to congregate in freshwater habitats such as rivers, lakes, wetlands and sometimes in brackish water and saltwater.
The lifespan of crocodiles varies depending on the species. In the wild, large crocodile species tend to live between 60 and 70 years, while smaller species live for 30 to 40 years on average.
Size greatly varies between species.
The smallest crocodile is the dwarf crocodile (Osteolaemus tetraspis). It grows to about 1.5 meters (4.9 feet) in length and weighs 18 to 32 kg (40 to 71 pounds).
The largest crocodile is the saltwater crocodile (Crocodylus porosus). It grows up to 7.0 meters (23.0 feet) in length and weighs up to 1,200 kilograms (2,600 pounds).
All crocodiles are characterized by a lizardlike shape and a thick skin composed of close-set overlapping bony plates.
They have a relatively long snout which varies considerably in shape and proportion. Their nostril, eye, and ear openings are the highest parts of the head allowing the crocodile to lie low in the water, almost totally submerged and hidden from prey.
As added protection while in the water, their eyes can be covered with semitransparent membranes, and the ears and nostrils can be closed over by folds of skin.
Its streamlined body enables it to swim swiftly, it also tucks its feet to the side while swimming, which makes it faster by decreasing water resistance.
Webbed feet are an advantage in shallower water, where the animal sometimes moves around by walking.
Like other reptiles, crocodiles are cold-blooded. They regulate body temperature by changing what environment they are in. If they need to warm up, they bask in the sun. If they need to cool down, they move to shade or into the water.
Crocodiles have acute senses, an evolutionary advantage that makes them successful predators.
Crocodiles have very good night vision, and are mostly nocturnal hunters. They use the disadvantage of most prey animals’ poor nocturnal vision to their advantage.
Crocodilian sense of smell is very well developed and they also can hear well.
They are ambush predators, waiting for fish or land animals to come close, then rushing out to attack.
Crocodiles are carnivores (meat-eaters). They mostly eat fish, amphibians, crustaceans, molluscs, birds, reptiles, and mammals, and they occasionally cannibalize smaller crocodiles.
As cold-blooded predators, they have a very slow metabolism, so they can survive long periods without food. Larger crocodiles can go for over a year without eating a meal.
Crocodiles have the strongest bite of any animal in the world. Despite this, however, the muscles that open the crocodile’s jaws are not very powerful. A strong person could hold a crocodile’s mouth closed with their bare hands!
Crocodiles have between 60 and 72 teeth which they use to tear flesh apart. They do not chew their food, but instead swallow large portions of their prey.
The social lives of crocodiles is complex. They are more social than all other reptiles. Though they primarily lead solitary lives, they resort to group behavior for important activities such as hunting or raising hatchlings.
Crocodiles lay eggs, which are either laid in hole or mound nests, depending on species. They lay 10 to 60 eggs at a time. The average incubation period is around 80 days, and also is dependent on temperature and species that usually ranges from 65 to 95 days.
After the young have hatched, the mother carries them to the water in her mouth and then guards them for most of the first year of their lives. Although they know how to swim from the time they hatch, sometimes the babies get to ride on Mom’s back, too. She threatens or attacks any predator that lurks too close; mothers of some species call the hatchlings to swim into her mouth for protection—making it look like the youngsters have been swallowed!
Crocodiles keep growing all their lives.
Crocodiles are one of the planets oldest living creatures, thought to be around 230 million years old which means that crocodiles were around in dinosaur times.
A male freshwater crocodile lived to an estimated age of 120–140 years at the Australia Zoo.
They can swim up to 30 kilometers (18 miles) per hour and can hold their breath underwater for around one hour.
Crocodiles are very fast over short distances, even out of water. The land speed record for a crocodile is
17 kilometers (11 miles) per hour, measured in a galloping Australian freshwater crocodile.
Crocodiles are polyphyodonts (animal whose teeth are continuously replaced). They are able to replace each of their teeth up to 50 times in their lifetime.
It is illegal to hunt crocodiles for their skin. This makes their skin very rare. A crocodile skin purse can cost $ 15,000.
Many species are at the risk of extinction, some being classified as critically endangered.
The Cuban crocodile is one of the world’s most endangered species of crocodile. It is considered critically endangered and has a population of only about 4,000.
Although they appear to be similar to the untrained eye, crocodiles and alligators are not the same. Alligators tend to have wide, U-shaped, rounded snouts, while crocodiles tend to have longer, more pointed, V-shaped snouts.The fourth tooth on the lower jaw sticks up over the upper lip on crocodiles, so you can see it when their mouth is closed. In alligators, this fourth tooth is covered up.
The term “Crocodile tears” refers to a false, insincere display of emotion, such as a hypocrite crying fake tears of grief. In fact, crocodiles can and do generate tears, but they do not actually cry. Tears are normally only noticeable if the crocodile has been out of the water for a long time and the eyes begin to dry out.