Reptiles
American Crocodile
Crocodylus acutus · also called Central American alligator (incorrectly), cocodrilo
The American crocodile is the large crocodilian of the American tropics — a coastal, salt-tolerant predator that ranges from the tip of Florida to Peru. It is bigger than the alligator, more at home in the sea, and, despite the fearsome family name, one of the more retiring members of the group.
Overview
American crocodiles live along warm coasts and coastal rivers — mangrove forests, brackish lagoons, estuaries, and the lower reaches of rivers — from southern Florida and both coasts of Mexico through Central America and the Caribbean islands to northern South America. Salt glands on the tongue let them thrive where fresh water is scarce and even cross open sea between islands. In the United States they are near the northern edge of their range and are limited by cold winters.
Telling it apart from the alligator
In the small area of southern Florida where the two coexist, the American crocodile can be distinguished by its:
- Narrow, tapering, olive-grey snout with a raised area in front of the eyes;
- Visible fourth lower tooth when the mouth is closed;
- Coastal, salty habitat rather than fresh marsh and lake.
Behaviour and diet
American crocodiles are ambush predators that eat fish, crabs, turtles, birds, and mammals, with the diet broadening to larger prey as the animal grows. They are largely nocturnal and spend the day basking or resting in burrows and shaded banks. Compared with the Nile and saltwater crocodiles, they are shy and non-confrontational toward people; problem interactions are usually linked to habituation from feeding.
Reproduction
In the dry season, females build a nest — a mound of soil and vegetation, or a hole dug in a sandy bank — and lay 30 to 60 eggs, then guard the site for the roughly three-month incubation. Nest temperature sets the hatchlings’ sex. When the young call, the mother opens the nest and carries them to sheltered “nursery” water, defending them for a time.
Threats and conservation
The American crocodile is listed as Vulnerable, but with an improving trend in several countries. Historic hunting for hides and the loss of coastal wetlands to development were the main causes of decline. Today’s threats are habitat loss and disturbance, road mortality, entanglement in fishing gear, illegal killing, and, locally, conflict where large crocodiles overlap with beach tourism. The Florida recovery — aided by refuges and, oddly, a power-plant canal system — is one of the clearer crocodilian conservation successes.
American Crocodile: common questions
What is the difference between an American crocodile and an American alligator?
Several things. The crocodile has a narrower, more tapered, greyish-green snout with a distinctive hump in front of the eyes, and its enlarged fourth lower tooth is visible when the jaws are closed; the alligator has a broad, rounded, black snout and hides its lower teeth. The crocodile tolerates salt water and lives in coastal mangrove and estuary habitat, while the alligator is a freshwater animal. In the world, the only place the two species overlap is the canals and wetlands of extreme southern Florida.
Are American crocodiles dangerous to people?
Much less than their reputation suggests. The American crocodile is one of the shyer large crocodilians and generally retreats from humans. Attacks do occur — more so in parts of Mexico, Costa Rica, and Colombia where large crocodiles and people share rivers and beaches, and where feeding by tour operators has made some animals bold — but the species is not the habitual man-eater that the Nile or saltwater crocodile can be. In Florida, despite thousands of crocodiles living among millions of people, serious attacks are very rare.
How did the American crocodile recover in Florida?
By the 1970s hunting and the draining and developing of coastal wetlands had reduced the Florida population to a few hundred, and it was listed as endangered. Protection under the Endangered Species Act, the creation of refuges in the Everglades and Biscayne Bay, and — unexpectedly — the crocodiles' colonisation of the warm cooling canals of the Turkey Point power plant, which turned out to be excellent nesting habitat, allowed numbers to climb past 2,000. The Florida population was downlisted from endangered to threatened in 2007.
Can American crocodiles really swim in the ocean?
Yes. Like the saltwater crocodile, the American crocodile has salt-excreting glands on its tongue and can spend extended time in fully marine conditions. It routinely lives in coastal lagoons and mangroves, and individuals have crossed open water between Caribbean islands and turned up far from any river mouth, which is how the species colonised places like the Cayman Islands and parts of the Antilles.