The 8 Main Differences Between Alligators and Crocodiles
Many people are unaware that there's a difference between alligators and crocodiles and use both terms interchangeably to describe any large water-dwelling lizard with big teeth. What they don't realize is that, despite some similarities, the two reptiles don't look or behave the same. They also belong to different biological families.
So what's the difference between alligators and crocodiles? Here are eight ways to tell them apart:
- Shape of the snout. The crocodile's snout is pointed and V-shaped, and the alligator's is wide and U-shaped.
- Location. Alligators are only found in parts of the US and China, whereas crocodiles can be found across the world. Scroll down for more information about where you'll find each.
- Habitat. Crocodiles prefer water that is more saline or salty than the alligator's preferred freshwater habitat.
- Toothy grin. Crocodiles can't hide their teeth, but alligators' teeth are sometimes hidden when their mouths are closed.
- Size. A full-grown crocodile will likely be several feet longer than an adult alligator.
- Color. Crocodiles are generally lighter in color than alligators.
- Speed. On land and in water, crocodiles are usually slower than alligators.
- Behavior. In terms of aggression, an alligator might seem tame compared to a crocodile.
Once you understand the differences, it is actually pretty easy to tell them apart. I explore each of these differences in detail below.
1. Alligators and Crocodiles Have Different Snouts
One of the main differences between alligators and crocodiles is the snout.
The alligator's is broader and shaped like a U, whereas the crocodile’s is longer and narrower and more V-shaped.
It's very possible that the alligator's snout shape is different because of diet, especially breaking open turtle shells, whereas the crocodile’s snout is more suited to hunting general prey including fish, reptiles, and mammals.
2. Where Do Alligators and Crocodiles Live?
Alligators live only in the southeastern US and eastern China, whereas crocodiles can be found across the world in Africa, Australia, Southeast Asia, North America, South America, and Central America.
If you are in the US, then you are far more likely to encounter an alligator than a crocodile. Although there is an American crocodile species, they only live in the southernmost tip of Florida, whereas alligators can be found across Florida and Louisiana, as well as in parts of Georgia, Alabama, Mississippi, North and South Carolina, Texas, Oklahoma, and Arkansas.
Alligators also heavily outnumber crocodiles in the US. There are over 3 million alligators, but fewer than 2,000 crocodiles. Southern Florida is the only place in the world where you will find crocodiles and alligators living side by side.
3. Habitat: Freshwater or Saltwater?
Crocodiles have special glands in their tongues which excrete excess salt from their bodies. This means that they are capable of spending days, or even weeks, at sea.
Alligators also have these glands but they don’t work as well, so they usually stick to freshwater habitats, although they can sometimes be found in brackish water (a mixture of salt and freshwater).
This difference explains why crocodiles have managed to spread across the islands of the Caribbean, and alligators haven't.
4. They Have Different Teeth
When their mouths are closed, the snouts of alligators and crocodiles are easy to tell apart, as the alligator will have none of its bottom teeth visible, whereas the crocodile’s lower fourth tooth can always be seen.
Crocodiles often have many visible teeth sticking out over their lips, giving them a very jagged "smile," but since an alligator's upper jaw is wider than its lower, it can hide all its teeth when its mouth is closed.
5. Which Are Bigger: Alligators or Crocodiles?
An adult crocodile can grow up to roughly 19 feet long, whereas for alligators, the maximum length is around 14 feet.
6. Color Differences
Crocodile hides tend to be more of a light tan or olive color, whereas alligators are usually a dark blackish grey.
(The exact shade of an alligator skin depends on the quality of the water it swims in. Tannic acid from overhanging trees will make them darker, algae will make them greener).
7. Which Runs and Swims Faster: An Alligator or a Crocodile?
On Land: Both can can move quickly on land, but only for short distances. They can both "gallop" or "sprint" but only do it when threatened, and not for long. A crocodile might reach almost 9 mph (14kph), while an alligator might reach a maximum speed of about 11 mph (18 kph).
In Water: They're both much more agile and fast in water where they can use their long, muscular tails to propel their bodies forward. When crocodiles swim, they might reach speeds of about 9 mph (15 kph), while alligators might reach a maximum of 20 mph (32 kph).
Did you know?
Fatalities from alligator attacks in the US are actually very rare. The average annual fatality rate for death by alligator in the US is actually only 0.3. That means on average, one person dies every three years. That's a very small figure when you consider how many people and alligators there are in southeastern US. The truth is that you are more likely to be killed by a dog, a bee or wasp sting, spider bite, rattlesnake, mountain lion, or shark.
8. Which Is More Aggressive: An Alligator or a Crocodile?
Alligators, while definitely dangerous, are relatively timid compared to crocodiles. An alligator will generally try to escape if approached by humans, usually heading for the nearest water.
The only time that wild alligators will attack humans is if they are unexpectedly disturbed, provoked, or defending their young.
Alligators are instinctively afraid of humans but can lose some of that fear with regular contact. Except in controlled conditions, feeding them is almost always a bad idea as they will lose some of their fear and see humans as a source of food. They can also mistake small children and pet dogs for prey.
Crocodiles, on the other hand, are much more bad-tempered and far more likely to attack humans, even unprovoked.
Australian saltwater crocodiles are generally considered the most dangerous in the world, followed by Nile crocodiles. American crocodiles, on the other hand, are one of the more timid types that you will find and rarely attack humans. In the US, you are more likely to be attacked by an alligator than a crocodile, although attacks by either are very rare.
Frequently Asked Questions
Are alligators and crocodiles the same species?
Crocodilia is an order of large, semiaquatic, predatory reptiles that includes alligators, caimans, gharai, and crocodiles. These are all known as "crocodilians," but only some are true crocodiles, and they're not related closely enough to interbreed.
Alligator vs. Crocodile: Which is stronger? If they fought, who would win?
Crocodiles can grow bigger than gators, and their bites can be more lethal.
Crocodiles might win for bite strength alone. The strongest have a bite pressure that measures 3,700 pounds per square inch, while the strongest alligators' bites are about 2,900.
In terms of size, crocodiles win again. The biggest recorded croc was about 2,000 pounds and over 23 feet long, while the largest recorded gator was about 1,000 pounds and 19 feet long.
Lastly, in terms of aggression, crocodiles would still win, as they are much more aggressive and likely to attack, even if unprovoked.
Which are more dangerous to humans?
According to CrocBITE, a database that keeps track of crocodilian attacks worldwide, the Nile crocodile is the one humans should be the most afraid of. Since the year 2000, there have been 33 human fatalities caused by American gators and crocodiles combined compared to 268 caused by Nile crocodiles alone.
Questions & Answers
© 2011 Paul Goodman