Gator or Crocodile?
Get to Know: Crocodilians
Alligators and crocodiles both come from the reptile order Crocodilia. The crocodilians are all large, predatory, semi-aquatic reptiles that can be traced as far back as 250 million years ago. The group includes alligators, caimans, crocodiles and gharials. Photo courtesy of Florida Fish and Wildlife; top to bottom: crocodile, caiman, alligator.
Predators in Water and on Land
All crocodilians can swim as fast as 20 mph and run up to 11 mph, and they can hold their breath underwater for close to an hour. But crocodiles have been known to be more aggressive than alligators. Photo courtesy of Florida Fish and Wildlife.
Saltwater v. Freshwater
The greatest biological difference between alligators and crocodiles is that alligators do not have functioning salt glands on their tongues. This makes them much less tolerant of the brackish and saltwater ecosystems inhabited by their cousin, the crocodile. Photo by Will Hollerith.
In wetland ecosystems, the American alligator constructs small ponds that retain water during the dry season, acting as oases for other aquatic animals. By modifying wetland habitats, the American alligator has become a keystone species to parts of the Louisiana bayou and Florida Everglades. Entire ecosystems are dependent upon alligators' presence. Photo courtesy of Florida Fish and Wildlife.
Gators: Still A Threatened Species
Though on the brink of extinction in the 1960s, over a million American alligators (Alligator mississippiensis) now inhabit the coastal states of the Southeast, from Texas to North Carolina. The U.S. Fish and Wildlife Commission still classifies the American alligator as threatened, however, because of its similarity to the American crocodile, also a threatened species. Photo by Leslie Velarde, courtesy of Everglades National Park/National Park Service.
Shape of the Snout
An alligator’s snout is broad, rounded and U-shaped, while a crocodile’s snout is a more narrow and tapered, V-shaped. Unlike their cousin the alligator, the fourth bottom tooth on all crocodiles is visible when their mouths are closed. Photo by R. Cammauf courtesy of the National Park Service.
The American Croc
The American crocodile (Crocodylus acutus) is much less aggressive compared with the notorious Nile and Australian saltwater crocodiles. The average lifespan of crocodiles in the wild is 70 years. Males have been recorded longer than 20 feet, but they rarely exceed 13 feet in the U.S.—lucky us. Photo courtesy of Everglades National Park/National Park Service.
A Rarity in the Wild
American crocodiles are a threatened species but are still protected from illegal harassing, poaching or killing under the federal Endangered Species Act. There are approximately 500 to 1,500 American crocodiles in the U.S., only found in the fresh and saltwater wetlands of southern Florida such as Biscayne National Park and Everglades National Park. Photo by Roy Wood courtesy of the National Park Service.
The American alligator and crocodile diet consists of fish, various mammals, birds, insects, crabs and other reptiles—basically whatever they can sink their teeth into. However, both species are known to turn and run before attacking a human. Photo courtesy of Everglades National Park/National Park Service.
Currently, the greatest threat to the American alligator and crocodile populations in the U.S. is habitat destruction. This includes water management systems and increased levels of mercury and dioxins in the water. Photo by Jessica Therriault courtesy of Florida Fish and Wildlife.