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What is a Crocodile?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

A crocodile is a semi-aquatic reptile in the order Crocodilia. Reptiles in this order are collectively known as crocodilians, and they include the true crocodiles, along with alligators, caimans, and the gharial, a very rare Indian reptile. Crocodilians can be found all over the world, typically near large deposits of salt or freshwater, with many species being considered threatened due to habitat pressure and hunting.

Several traits are common to all of the members of this order of reptiles. They are incredibly strong, with bodies built for predation, including powerful tapering jaws. A crocodile can take down prey much larger than it is, and multiple animals can be essentially unstoppable. They also have an extremely keen sense of hearing, and they communicate with a wide range of vocalizations, including grunts, coughs, and barks.

Crocodiles prefer an aquatic habitat.
Crocodiles prefer an aquatic habitat.

As a general rule, these reptiles are carnivores, and most are not picky about what they eat. Fish, small mammals, and larger prey like oxen are all fair game to a hungry croc, as are humans. Like other reptiles, they use basking to regulate their internal temperatures, preferring banks near their aquatic habitat so that they can slip underwater if threatened. Crocodiles tend to be more active at night, and some burrow into the bank to nest, with only their nostrils protruding.

Crocodiles have tough, scaly skin that acts as armor.
Crocodiles have tough, scaly skin that acts as armor.

Crocodiles are also covered in thick, scaly skin that acts like armor. Depending on the species, they can reach up to 16 feet (5 meters) in length, and some individuals may live to be well over 100 years old. These animals are also quite intelligent, able to work in groups when necessary and to patiently lie in wait for prey.

One interesting trait of animals in this order is the habit of swallowing stones. The stones may act as ballast, allowing the animals to dive, and they may also play a role in digestion. Researchers who focus on crocodilians have found that the reptiles can “make change” with their ballast stones when presented with an assortment of stones to swallow; they will disgorge stones if necessary to make the right weight. This habit is referenced in the animal's name, which comes from the Greek kroke, which means “pebble,” and drilos, or “worm.”

A crocodile.
A crocodile.

As a general rule, crocodiles are found in tropical and semitropical regions of Africa, Asia, and the Americas. Many people use the term specifically to refer to the true crocodiles, differentiating these crocodilians from their cousins, the alligators and caimans. Crocodilians are physically fairly similar, although true crocodiles have distinctive protruding lower teeth that are visible even when their jaws are closed, making it easy to distinguish between these animals and alligators.

Frequently Asked Questions

What distinguishes a crocodile from an alligator?

Crocodiles and alligators are often confused, but they have distinct differences. Crocodiles generally have a V-shaped snout and display a fourth tooth on the lower jaw when their mouths are closed. In contrast, alligators have a U-shaped snout, and their teeth are not visible when their mouths are shut. Additionally, crocodiles are typically more aggressive and can be found in saltwater habitats, whereas alligators prefer freshwater environments.

How long can crocodiles live?

Crocodiles are known for their impressive longevity, with many species living for 70 to 100 years. The Saltwater Crocodile, for instance, can live up to 70 years or more. Their long lifespan is attributed to their slow metabolism and ability to survive long periods without food. This longevity contributes to their status as apex predators in their ecosystems.

What do crocodiles eat?

Crocodiles are carnivorous and have a diet that consists mainly of fish, birds, and mammals. They are opportunistic hunters and will consume almost any animal they can overpower, including small hippos, water buffalo, and occasionally even sharks. Their powerful jaws and ambush hunting tactics make them formidable predators in their aquatic habitats.

How fast can crocodiles swim?

Crocodiles are adept swimmers and can reach speeds of up to 15 to 18 mph (24 to 29 km/h) in short bursts when they are hunting or escaping danger. Their streamlined bodies and powerful tails enable them to navigate through water with both speed and agility, making them efficient aquatic predators.

Are crocodiles endangered?

The conservation status of crocodiles varies by species. Some, like the Saltwater and Nile crocodiles, are at lower risk due to conservation efforts, while others, such as the critically endangered Gharial and the Philippine Crocodile, face significant threats from habitat loss and poaching. International efforts, including CITES regulations, aim to protect these ancient reptiles.

How do crocodiles reproduce?

Crocodiles are oviparous, meaning they lay eggs. Females build nests either on riverbanks or in floating vegetation and lay between 20 to 80 eggs. They exhibit maternal care, guarding the nests vigilantly until the eggs hatch. Temperature during incubation determines the sex of the offspring, a phenomenon known as temperature-dependent sex determination.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllThingsNature researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllThingsNature researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

Discussion Comments

kentuckycat
@jcraig - That is absolutely correct, and that is probably the reason why there are not very many legends about killer alligators, but there are many that concern crocodiles in Africa.

The crocodile is one of the most feared animals in the world due to their aggressive nature and their largeness.

Because of this, villages throughout the world have created local legends about killer crocodiles. However, if one looks at killer alligator stories there are very few, except in some isolated incidents in which an attack may have happened.

I personally know of a story of a killer crocodile in Africa in which the crocodile has been blamed for numerous deaths and has survived for nearly 100 years.

Alligators simply do not put near as much fear into people as crocodiles do across the globe.

jcraig
I have always heard that although alligators are dangerous animals, they will shy away from people, unless they are provoked or sense harm.

Now crocodiles on the other hand -- I have heard that they will react to anything and everything around them and are quite aggressive.

That being said, this is why there are a lot of people in the United States that hunt alligators, but when crocodile hunters are looking for crocodiles, they usually are doing so in order to protect their village or to protect people in the surrounding area.

This is one major difference between crocodiles and alligators, in that crocodiles are amazingly more aggressive than their closely related cousins.

Izzy78

I have always found it interesting that people who do not know very much about animals always seem to confuse alligators and crocodiles.

I have always figures that the differences between alligators and crocodiles consist of very small differences, as they are essentially the same animal, but have subtle differences, like size, and small differences in their basic features.

I have also noticed that alligators only seem to live in America, as opposed to crocodiles that seem to live on several different continents.

I find this to be quite unique as one would think that these two closely related creatures would live in the same areas. Could someone explain to me why this is the case and if it has something to do with climate?

anon284687

The largest crocodile measured was 28 feet and the largest alligator measured is only 19 feet so there is a huge difference between them. Also, crocodiles have a crushing force of 3 tonnes of pressure per sq.in but alligators only have a crushing force of only 900 kilos of pressure per sq.in.

Therefore, crocodiles are stronger than gators. Also all the crocs I have seen have needle sharp teeth, but all gators I have seen have extremely blunt teeth.

anon284441

Crocodiles can grow to 33 feet long. They also are much much stronger than alligators.

anon284410

The Australian saltwater crocodile can reach lengths of up to 33 feet and a crushing force of 3 tonnes.

googie98

@purplespark: Here’s a little more information for you:

Crocodiles reach the age of sexual maturity between the ages of 8 and 12. The female crocodile lays anywhere from 20 to 90 eggs at a time. They hatch within 90 days.

The crocodile has a four chambered heart like mammals and birds. The largest crocodile is the Saltwater crocodile with a length of up to 20 feet or more. The smallest crocodile is the Cuvier’s Dwarf Caiman which is just a little over 5 feet long.

The best way to tell the difference in a crocodile and an alligator is by looking at the teeth. When a gator closes its mouth, all of the teeth fit inside and none are showing. When a croc closes its mouth, there will be one tooth on each side exposed.

CellMania

@purplespark: Crocodiles are normally a greenish-grey color with a triangular shaped narrow snout. They do not shed their skin like most reptiles. Instead, they grow into it. Crocodiles do not have sweat glands. They release heat through the cavities in their mouth. They often pant like a dog to release hit.

The crocodile’s back feet are webbed. They can move at a speed of up to 28 mph on land.

PurpleSpark

Great article. Does anyone have any more specific information about crocodiles?

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    • Crocodiles prefer an aquatic habitat.
      By: stuporter
      Crocodiles prefer an aquatic habitat.
    • Crocodiles have tough, scaly skin that acts as armor.
      By: gijssmulders
      Crocodiles have tough, scaly skin that acts as armor.
    • A crocodile.
      A crocodile.