America now has three kinds of crocodilians. What are they?
Q. How many kinds of alligators and crocodiles live in the United States? In a recent discussion I said one. Everyone knows about alligators. Someone said crocodiles are found in Florida. Then somebody else piped up that a third crocodile also lives in Florida. What’s the right answer? One, two or three? And what is the general name for these animals?
A. The simple answer is that two kinds of crocodilians (the catch-all name for alligators, crocodiles and tropical American alligators called caimans) are native inhabitants in the United States. But your friend is correct in saying we now have a third. Established populations of a nonnative caiman have recently been documented in southern Florida.
You are correct that everybody knows about alligators, but people who have moved to the Southeast from northern or western states are often uncertain about whether alligators live in their area.
The northernmost natural localities of American alligators are in North Carolina near Cape Hatteras. In all coastal states from the Carolinas to eastern Texas, alligators are most common in the warmer southern or coastal portions. They are likely to occur in a third to half of most of those states. Alligators can also be found in small areas of Arkansas and southeast Oklahoma.
The American crocodile, which lives in Cuba, Mexico, Central America and northern South America, is a native U.S. species inhabiting a few brackish water habitats near Miami and the Everglades.
An American crocodile can be distinguished from an alligator by its snout, which is long and narrow compared to an alligator’s broader one. An ecological distinction is that crocodiles lay their eggs in a hole they dig in the sand, whereas alligators build a nest of mud and vegetation above ground and deposit their eggs inside to incubate. Males of both species commonly reach lengths of more than 12 feet.
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According to “Exotic Amphibians and Reptiles of the United States” (University Press of Florida, 2022) by Walter Meshaka and colleagues, the spectacled caiman is now established in four or more populations near Miami.
The species is readily distinguishable by a bony ridge between the eyes on the base of the snout. Most caimans reported from Florida have been no more than 6 feet in length. The native range of spectacled caimans, which look and behave much like alligators, is through Central America and the northern half of South America.
Their presence in Florida is attributed to releases from the commercial pet trade. Interestingly, caiman colonies are not currently in the Everglades. How they might fare in the wild with alligators and Burmese pythons remains undetermined.
Caimans in the United States, hundreds of miles outside their natural range, are but one more example of an introduced species making a successful living in its new environment.
The natural world order of animal and plant distribution patterns has become irreparably altered because of human beings moving species between and within continents for more than four centuries.
The ecological kaleidoscope in the United States changes every year. The number of Asian plants that thrive in neighborhoods across the country is virtually uncountable. Giant Burmese and northern African python constrictors are here to stay in the Everglades and points farther north. European starlings and house sparrows from England outcompete native birds in many areas.
Other countries have also been impacted, such as African hippopotamuses thriving in Colombia, rabbits and foxes in Australia and U.S. gray squirrels in England.
I would rate the endless government programs to combat what some consider the more insidious invaders, such as fire ants and kudzu, as mostly unsuccessful despite millions of dollars spent to eliminate them. They are here to stay.
So are mongooses in Hawai’i and lampreys in the Great Lakes. Cuban treefrogs have hopped through Florida into Georgia and probably Alabama. We may as well learn to live with the new biodiversity. Having another crocodilian in our own mix will probably not make much difference.
Whit Gibbons is professor of zoology and senior biologist at the University of Georgia’s Savannah River Ecology Laboratory. If you have an environmental question or comment, email ecoviews@gmail.com.
This article originally appeared on The Tuscaloosa News: What are the 3 three kinds of crocodilians in the U.S.?
