American Crocodile (Crocodylus acutus): Facts and Range

What does an American crocodile look like?

The American crocodile is a typical true crocodile in shape: long body, short sturdy legs, a powerful flattened tail and a back armored with rows of bony plates called osteoderms. Compared with other crocodiles, its back armor is relatively reduced and the plates are arranged more irregularly.

Adults are a pale grayish-olive to tan color, noticeably lighter than the dark American alligator. Young crocodiles are lighter still, with dark crossbands on the body and tail that fade with age.

The snout is long and fairly narrow, broader than that of a specialist fish-eater like the gharial but narrower than an alligator’s. A distinctive raised bump lies on top of the snout in front of the eyes, which helps experts tell it apart from other crocodiles. As in all crocodiles, the fourth tooth of the lower jaw fits into a notch in the upper jaw and stays visible when the mouth is closed. The page alligator vs crocodile explains the main ways to tell the two groups apart.

How big do American crocodiles get?

The American crocodile is one of the larger crocodile species, although most individuals are much smaller than the famous giants of Africa and Australia.

Size depends on the population. In Florida, adults commonly measure 2.5 to 3.8 m (8 to 12.5 ft). In rich river systems in Central America some males grow larger, and a male measured in Costa Rica at 4.83 m (15 ft 10 in) weighed around 540 kg (1,190 lb). Old reports of animals 6 to 7 m (20 to 23 ft) long have never been confirmed.

Habitat and range

American crocodiles have the largest range of the four crocodile species native to the Americas. They live in:

• North America: the southern tip of Florida, both the Pacific and Caribbean coasts of Mexico including the Yucatán Peninsula, and every Central American country.
• The Caribbean: Cuba, Jamaica and Hispaniola (the Dominican Republic and Haiti), with recent sightings on Grand Cayman.
• South America: the coasts and lowland rivers of Colombia and Venezuela, and the Pacific coast south to Ecuador and northern Peru.

The species is strongly tied to the coast. Its favorite habitats are mangrove swamps, brackish lagoons, estuaries and river mouths, and it also lives on small cays and islands with no fresh water at all. Some populations live inland on rivers and lakes. One of the largest populations in the Caribbean lives in Lago Enriquillo, a salt lake in the Dominican Republic that is saltier than the sea.

How do American crocodiles cope with salt water?

Like other true crocodiles, the American crocodile has salt glands on its tongue that excrete excess salt. This lets adults live in seawater for long periods, and the species is second only to the saltwater crocodile in how often it is found at sea. It can drink fresh water from rain or rivers when available, and it gets much of its water from its food.

Hatchlings are the weak point. They are more sensitive to high salinity, and studies in Florida Bay found that young crocodiles in water saltier than the sea grew more slowly and survived less often. Nesting females therefore tend to choose sites near less salty water. For how this works in all crocodiles, see Can crocodiles live in salt water?

Diet and hunting

American crocodiles are carnivores and top predators in their habitats. Hatchlings eat insects, small fish, snails and crabs, including fiddler crabs. As they grow, they take larger fish such as mullet, catfish and tarpon, plus crabs, turtles, snakes, wading birds and mammals such as raccoons and opossums.

Large adults can tackle big prey, including dogs, goats, pigs and occasionally cattle, but most of their diet is fish and other aquatic animals. In Costa Rica, American crocodiles have been seen ambushing nesting olive ridley sea turtles on beaches.

Like other crocodilians they hunt mostly by ambush, often at night, waiting motionless at the surface with only eyes and nostrils showing and then lunging. They can move quickly over short distances on land but cannot keep it up; How fast can crocodiles run and swim? explains the numbers.

Behavior

American crocodiles are mostly solitary, though several may gather to bask or feed where food is plentiful. They are most active at night and spend many daylight hours basking on banks or resting in shaded water. Basking crocodiles often lie with their jaws wide open, which helps them shed heat.

They are more sensitive to cold than American alligators. Long spells of cold water can stun or kill them, which is the main reason the species does not live farther north than south Florida. In cold snaps they retreat to deeper water or burrows.

Adults communicate with low bellows during courtship, head slaps on the water and body postures, and hatchlings call to their mother with high-pitched chirps.

Reproduction and life cycle

Courtship takes place in late fall and winter. Females mature when they reach about 2.2 to 2.8 m (7 to 9 ft) long, a size that often takes around ten years or more to reach.

Nests are usually holes dug into sandy beaches, river banks, canal banks or raised mounds of marl, although some females build mounds. A female lays about 30 to 70 eggs, with an average of around 38, and may return to the same nest site for many years. In Florida, eggs are laid in April and May and hatch in July and August after about 75 to 90 days.

As in all crocodilians, the temperature inside the nest decides the sex of the young. The mother stays nearby during incubation. When the hatchlings call from inside the eggs, she digs them out and often carries them to the water in her mouth, then guards them for a few weeks before they disperse. Only a small share of hatchlings survive to adulthood; raccoons dig up many nests, and young crocodiles are eaten by wading birds, large fish, crabs and other crocodiles. Do crocodiles care for their babies? compares this with other species.

Relatives and evolution

The French naturalist Georges Cuvier described the species in 1807. Its closest relatives are the other crocodiles of the Americas: the Orinoco crocodile of Venezuela and Colombia, Morelet’s crocodile of Mexico and northern Central America, and the Cuban crocodile. Fossils and genetic studies suggest that the ancestors of all four crossed the Atlantic from Africa several million years ago, almost certainly by swimming and drifting, since true crocodiles tolerate salt water.

The species is not uniform. Crocodiles from Florida, Jamaica and Hispaniola differ genetically, and some island populations off the Yucatán may prove to be distinct enough to be split off in the future.

Myths and facts

Myth: alligators keep crocodiles out of north Florida. The limit is climate, not competition. American crocodiles cannot survive long periods of cold water, while alligators can, so crocodiles stay in the warm far south.

Fact: crocodiles and alligators rarely fight. In south Florida the two species mostly use different habitats, with crocodiles in salty coastal water and alligators in fresher marshes, so conflicts between them are uncommon.

Threats and conservation status

The IUCN Red List classes the American crocodile as Vulnerable. During the 20th century, hunting for leather and habitat destruction wiped out or greatly reduced many populations across its range. Today the main threats are coastal development, the loss of mangroves, illegal killing, drowning in fishing nets and road traffic. In some areas it hybridizes with the Cuban crocodile and with Morelet’s crocodile.

International trade is controlled under CITES Appendix I for most populations. In the United States the species was listed as endangered in 1975, when only a few hundred crocodiles remained in Florida. Protection of nesting habitat, including Crocodile Lake National Wildlife Refuge on Key Largo, allowed numbers to climb, and in 2007 the Florida population was reclassified from endangered to threatened. Florida now has an estimated 2,000 or more adults; Are there crocodiles in Florida? covers their story.

Relationship with people

The American crocodile is less aggressive than the Nile or saltwater crocodile, and most individuals avoid people. Attacks still happen, especially in parts of Mexico and Costa Rica where crocodiles have become used to humans, sometimes because people feed them. In Florida, bites are extremely rare. Respecting the animals means keeping well back, never feeding them and keeping children and pets away from the water’s edge in crocodile areas. Anyone who is bitten should seek emergency medical help immediately.

Crocodiles are a big draw for ecotourism. Boat tours on the Tárcoles River in Costa Rica, the mangroves of the Yucatán and the Flamingo area of Everglades National Park let visitors watch them safely, and they bring income that gives local people a reason to protect the animals. Their close relative the American alligator shares the coastal marshes of south Florida, the only place in the world where alligators and crocodiles live side by side.