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Critter Guide
Reptiles & Amphibians: Alligators and Crocodiles


These animals are so ancient that they once walked with dinosaurs. During the Reptile Age, which lasted 100 million years, crocodiles were the most dominant animal on earth. Today, only 12 crocodilian species are left, and many of them are on the verge of extinction due to hunting and habitat destruction by humans.

It's hard to tell alligators and crocodiles apart, but knowing just a few facts will make you become an expert:
  • Shape of head: Crocodiles have long, V-shaped snouts whereas alligators have short, U-shaped snouts.

  • When their jaws are closed, you can still see the fourth tooth on the lower jaw of the crocodile. When an alligator closes its mouth, that tooth disappears. So, in general, if the jaw is closed and you still see lots of teeth, it's a crocodile.

  • What type of water are they in? They prefer very different homes and knowing what habitat they like can also identify which one is which. Keep reading below.

Where do they live?:

American alligators live only in fresh water in rivers, marshes, and lakes in the southeastern part of the U.S. American crocodiles like brackish or salt water and are found only in the southern tip of Florida. Crocodiles are very sensitive to the cold and stay where it's warmest.

What do they eat?:

Both the American alligator and American crocodile are nocturnal. They eat fish, turtles, and even raccoons and birds. They will also scavenge dead animals and sometimes resort to cannibalism.

Social Environment:

Both animals have complex social behaviors, especially during courtship. Males exhibit aggression through vocalizations and body language towards rivals as the females move through their territories. Crocodiles in particular have very elaborate courtship displays that take place before mating. The females may lay as many as five dozen eggs per year. Newborns stay with their mother for two years. As adults, females and males live apart.

Critter Fact:

Alligators and crocodiles don't chew their food. Instead, they grab their prey with their jaws and instinctively roll in order to tear off a chunk of meat, which they then swallow whole.

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Did You Know?

Around 10 million alligators and roughly 5 million crocodiles were killed between 1870-1970 for their skins, which were then made into shoes, belts, and handbags. In order to protect these animals, they were both classified as endangered under the federal Endangered Species Act. While the crocodile is still endangered, the alligator's population has rebounded and it is now listed as threatened. However, housing and other developments are fast encroaching on the gators' wetland homes. Once in danger of becoming extinct, alligators are now considered a nuisance animal when people find them in their backyards, golf courses, and swimming pools.

Related Episodes
The Reptiles: Alligators
   and Crocodiles
Springs Eternal:
   Florida's Fountain of