Alligator Facts

Scientific Names: A. mississippiensis and A. sinensis

The American alligator is a large carnivorous reptile.
The American alligator is a large carnivorous reptile. reptiles4all, Getty Images

The alligator is a freshwater crocodilian belonging to the genus Alligator. It is a large reptile with a fearsome set of teeth. In fact, the teeth are one way to tell an alligator from a crocodile. An alligator's teeth are hidden when its mouth is closed, while a crocodile still has a toothy grin. The name alligator comes from the Spanish el lagarto, which means "the lizard." Alligators are sometimes called living fossils because they have been around about 37 million years, first appearing in the fossil record in the Oligocene epoch.

Fast Facts: Alligator

  • Scientific Name: Alligator mississippiensis (American alligator); Alligator sinensis (Chinese alligator)
  • Common Name: Alligator, gator
  • Basic Animal Group: Reptile
  • Size: 13 feet (American); 7 feet (Chinese)
  • Weight: 790 pounds (American); 100 pounds (Chinese)
  • Lifespan: 35 to 50 years
  • Diet: Carnivore
  • Habitat: Freshwater marshes and grasslands
  • Population: 5 million (American); 68 to 86 (Chinese)
  • Conservation Status: Least Concern (American); Critically Endangered (Chinese)

Species

There are two alligator species. The American alligator is Alligator mississippiensis, while the Chinese alligator is Alligator sinensis. Several extinct species are found in the fossil record.

The Chinese alligator is critically endangered in the wild.
The Chinese alligator is critically endangered in the wild. reptiles4all, Getty Images

Description

Alligators range in color from brown to olive green to black with white bellies. Juvenile alligators have orange, yellow, or white marks that fade as they reach maturity. American alligators are much larger than Chinese alligators. The average American alligator is 13 feet long and weighs 790 pounds, but large specimens over 14 feet long and 990 pounds occur. Chinese alligators average 7 feet long and 100 pounds. In both species, males tend to be larger than females. An alligator's strong tail makes up over half its length.

Habitat and Distribution

The American alligator lives in the southeastern United States. It occurs in freshwater and brackish wetlands in Florida, Louisiana, Georgia, Mississippi, South Carolina, North Carolina, East Texas, and southern Arkansas and Oklahoma.

The Chinese alligator is found in a short section of the Yangtze River valley.

Diet

Alligators are carnivores, although they sometimes supplement their diet with fruit. The type of prey depends on the size of the alligator. They are ambush predators that prefer to eat prey that may be consumed in one bite, such as fish, turtles, mollusks, small mammals, and other reptiles (including smaller alligators). However, they can take much larger prey. Larger prey are grabbed and spun around in the water in what is called a "death roll." During a death roll, the gator bites off chunks until the target is subdued. Alligators may store prey under the water until it decomposes enough to be eaten. Like other cold-blooded animals, alligators cannot digest prey when temperatures drop too low.

Behavior

Alligators are excellent swimmers, plus they use three modes of locomotion on land. The "sprawl" is a walk using four legs with the belly touching the ground. The "high walk" is on four limbs with the belly above the ground. Alligators can walk on their two legs, but only for short distances.

While large males and females tend to be solitary within a territory, smaller alligators form highly social groups. Alligators readily tolerate other individuals of comparable size.

Gators are extremely intelligent. They have been known to use tools and find their way home from a distance of 30 miles.

Reproduction and Offspring

Alligators mature when they reach a length of around 6 feet. In the spring, male alligators bellow, emit blasts of infrasound, and head-slap water to attract mates. Both sexes gather in groups for courtship in what is called an "alligator dance." Males mate multiple females, but a female has one mate per season.

In the summer, a female builds a nest of vegetation and lays between 10 and 15 hard-shelled eggs. Decomposition supplies the heat needed to incubate the eggs. The temperature of the nest determines offspring sex. Temperature of 86 °F or lower produce females, while temperature above 93 °F produce males. Between 86 °F and 93 °F, a clutch contains both males and females.

The young hatch in September using an egg tooth and assistance from their mother. Female hatchlings weigh more than male hatchlings. The female defends the nest and helps the hatchlings reach water. She continues to guard her offspring for a year or two, but will mate each year once she reaches maturity.

It is unknown exactly how long alligators live in the wild. Estimates place average lifespan between 35 and 50 years. Alligators in captivity can live long lives. One captive specimen is at least 80 years old.

Alligator hatchlings have white or yellow marks.
Alligator hatchlings have white or yellow marks. DeSid, Getty Images

Conservation Status

The IUCN classifies the conservation status of the American alligator as "least concern." Approximately 5 million American alligators live in the wild. On the other hand, the status of the Chinese alligator is "critically endangered." As of 2018, between 68 and 86 mature individuals lived in the wild, with a stable population trend. At present, more Chinese alligators live in zoos than in the wild. Chinese alligators are protected, plus captive individuals may be successfully reintroduced into the wild.

Alligators and Humans

Alligators typically do not perceive humans as prey. While attacks sometimes occur, they tend to be provoked when a person encroaches on an alligator's territory, in self-defense, or where humans feed alligators and the reptiles have lost their natural shyness.

Alligators are hunted and raised commercially for skin and meat. Wild alligators are a popular sight for ecotourists. Alligators offer an economic benefit to humans by controlling muskrat, copypu (nutria), and other pest animal populations.

Alligators can be trained, but they do not make good pets because they grow very quickly, escape enclosures, and can be unpredictably aggressive.

Fun fact: While an alligator closes its mouth with force, its jaws are too weak to open when the mouth is held closed.
Fun fact: While an alligator closes its mouth with force, its jaws are too weak to open when the mouth is held closed. Zen Rial, Getty Images

Sources

  • Brochu, C.A. (1999). "Phylogenetics, taxonomy, and historical biogeography of Alligatoroidea". Memoir (Society of Vertebrate Paleontology). 6: 9–100. doi:10.2307/3889340
  • Craighead, F. C., Sr. (1968). The role of the alligator in shaping plant communities and maintaining wildlife in the southern Everglades. The Florida Naturalist, 41, 2–7, 69–74.
  • Crocodile Specialist Group (1996). Alligator mississippiensis. The IUCN Red List of Threatened Species 1996: e.T46583A11061981. doi:10.2305/IUCN.UK.1996.RLTS.T46583A11061981.en
  • Fish, Frank E.; Bostic, Sandra A.; Nicastro, Anthony J.; Beneski, John T. (2007). "Death roll of the alligator: mechanics of twist feeding in water." The Journal of Experimental Biology. 210 (16): 2811–2818. doi:10.1242/jeb.004267
  • Jiang, H. & Wu, X. (2018). Alligator sinensis. The IUCN Red List of Threatened Species 2018: e.T867A3146005. doi:10.2305/IUCN.UK.2018-1.RLTS.T867A3146005.en