Reptiles
Alligator
Alligatoridae · also called gator, caiman
An alligator is a crocodilian with a blunt, U-shaped snout and a smile that hides its lower teeth. There are only two true alligators — one in the American Southeast, one clinging on in the Yangtze — and their close cousins, the caimans, fill out the rest of the family. The American alligator is also one of conservation’s clearest wins, hauled back from the brink within a single lifetime.
Overview
Alligators are the family Alligatoridae, which split from the true crocodiles around 80 million years ago. It contains just two alligators — the abundant American alligator and the Critically Endangered Chinese alligator — plus six species of caiman in Central and South America. All are broad-snouted freshwater carnivores that eat almost anything they can catch, and, unusually for crocodilians, alligators sometimes eat fruit.
Alligator or crocodile
An alligator has a wide U-shaped snout and hides its lower teeth when its mouth is shut, because the big fourth tooth slots into a pit in the upper jaw. A crocodile’s snout is narrower and V-shaped, and that tooth stays visible in an external notch. Alligators handle cold better and salt worse, so they are animals of temperate fresh water.
Engineers and parents
In drought, alligators dig and keep open water-filled gator holes that carry fish, turtles, and birds through the dry season, raising a wetland’s biodiversity. The female builds and guards a nest mound, and its temperature sets the sex of the young — cooler nests female, warmer male. She then carries the hatchlings to water in her mouth and stays with them for a year or more.
Status
Alligators as a family are Not Evaluated. The American alligator was hunted to the brink for hides, protected in the 1960s, and fully recovered and delisted by 1987, now numbering in the millions. Most caimans are secure. But the Chinese alligator is down to around 150 in the wild in a few small Yangtze wetlands.
Alligator: common questions
What is the difference between an alligator and a crocodile?
They are separate families of crocodilian that split around 80 million years ago. The quickest field marks are the snout and teeth. An alligator has a broad, rounded, U-shaped snout, and with its mouth shut only the upper teeth show because the big fourth lower tooth slots into a pit in the upper jaw. A crocodile has a narrower, more V-shaped snout, and that fourth lower tooth sits in an external notch and stays visible when the mouth is closed, giving a toothy grin. Alligators also tolerate cold better and salt water worse, so they are freshwater animals of the southeastern United States and China, while crocodiles range through tropical estuaries and coasts worldwide.
Are caimans alligators?
Caimans are in the alligator family, Alligatoridae, so they are close relatives of the two true alligators rather than of the crocodiles, and like alligators they have broad snouts and hidden lower teeth. But they are not alligators in the strict sense; they form their own subfamily, Caimaninae, with six species ranging from the metre-long dwarf caimans to the black caiman, which rivals large crocodiles at over 4 to 5 metres. Caimans are found only in Central and South America. The spectacled caiman is one of the most abundant crocodilians in the world and has established an invasive population in southern Florida.
How did the American alligator recover from near extinction?
Unregulated hunting for the leather trade had reduced the American alligator to very low numbers across much of its range by the mid-20th century. It received legal protection from Florida in 1967 and federal protection under what became the Endangered Species Act, which stopped commercial hunting and cracked down on the illegal skin trade. Alligators breed well, mature in around 10 to 15 years, and had large areas of suitable wetland still available, so the population rebounded quickly. By 1987 it was declared fully recovered and delisted, and states now run tightly managed hunting and farming programmes. It is one of the earliest and clearest successes of endangered species legislation.
How dangerous are alligators to people?
Much less than their size suggests, though the risk is real. The American alligator causes on average around one human fatality per year in the United States, despite millions of alligators living alongside a large human population, and most serious attacks involve people swimming at dusk or night in alligator water, small children near the water's edge, or animals that have been fed by people and lost their wariness. Alligators are ambush predators and generally avoid humans. The main rules are never to feed them, keep pets and children away from the water in alligator country, and do not swim where alligators are known to be, especially at dawn and dusk.