Aquarium of the Pacific - Online Learning Center - Species Print Sheet
Conservation Status: Threatened
Climate Change: Uncertain
One of the largest North American reptiles, American alligators are often considered to be a keystone species, a predator that controls prey populations. Alligators are members of the Crocodilian order and although they resemble crocodiles, alligators are different. Among the differences, alligators have rounded snouts while most crocodile species have longer, pointed snouts. Also, crocodiles occur only in tropical and subtropical areas (in the United States, only in Florida), while alligators live in somewhat colder climates. With only their upward-pointing nostrils out of the water and the rest of their body underwater, they can easily be mistaken for submerged logs. American alligators have made a remarkable recovery after being hunted nearly to extinction for their skin and meat. Once listed as endangered under the U.S. Endangered Species Act, they are now listed as threatened.
At the Aquarium
It was necessary to obtain a permit from the California Department of Fish and Wildlife in order to exhibit American alligators in our Florida Everglades habitat. Our captive bred alligators were less than one year old when we received them in April 2016. They are on view in the Vanishing Animals exhibit in the changing exhibits gallery.
From North Carolina around the Florida panhandle to the Rio Grande River in Texas
Alligators are usually found in freshwater in swamps, marshes, slow-moving rivers, and lakes. Even though they lack salt glands, they are able to tolerate salt or brackish water for brief periods.
Alligators have a lizard-shaped body, a broad muscular tail, and four short legs that can carry them at a gallop on land. Their front legs have five webbed toes and the back legs four. Their snout is broad with upward-facing nostrils at the tip, allowing them to breathe air while fully submerged. They have 74 to 80 teeth at any one time. When a tooth wears down, it is replaced. One very large front tooth in the lower jaw that fits into a socket in the upper jaw is only visible when an alligator’s mouth is open. The skin on the back of an alligator is “armored” with embedded bony plates called osteoderms or scutes. Adults are olive-brown or black with a creamy white ventral side. Young alligators have a bright yellow stripes.
Females to 2.6 meters (8.2 feet) and males to 3.4 meters (11.2 feet) in length
Alligators hunt primarily at night. Carnivores, adults prey on fish, snails, birds, frogs, invertebrates, and mammals they capture when the potential meal comes to the water’s edge. They can crack a turtle shell with their very strong jaws. Their sharp teeth are used to seize and hold prey. Small prey are eaten whole. A larger prey is shaken to break it into smaller, manageable pieces or In the case of very large prey, bitten, held onto, and then spun to tear off easily swallowed pieces. Juveniles eat insects, crayfish, mollusks, small fish and amphibians.
Both sexes reach maturity when they are 10 to 12 years old and have reached a length of about 1.8 meters (6 feet). Courtship begins in April with mating occurring in early May. Breeding takes place in shallow waters during the night.
Males exhibit a number of courtship behaviors. They bellow loudly to attract mates or warn off other males by sucking air into their lungs and blowing it out in intermittent deep-toned roars; head slap as a sign of aggression to ward off intruders; lunge their head out of the water to show honorable intentions; and make the water “dance” as a result of sub-audible noises creating vibrations, bubbles and ripples in the water. They also purr.
After mating the female builds a nest of vegetation—sticks, leaves, and mud—in a sheltered spot in or near the water. The nest is 0.6-0.9 m (2-3 ft) high and 2.1 – 5.7 m (7-19 ft) in diameter. In late June or early July, the female lays 35-50 eggs. After she covers the eggs with vegetation she leaves them to incubate for about 65 days. The nest temperature determines the sex of the juveniles. Temperatures above 33.80C (930F) produce all males; below 300 C (860F) all females; and between the high and low, both sexes.
Toward the end of August the incubating gators begin to make high pitched whining noises from inside the egg to let the female know they are ready to hatch and it is time to remove the
Although they do not have vocal cords, American alligators are the most vocal of all crocodilians. Communication begins while they are still in the egg. As alligators roam, they bellow at each other. The bellow is throaty, loud, and can be heard up to 1.6 kilometer (1 mile) away. They also make cough-like purrs called chumps during courting. And they hiss.
Alligators are most active when temperatures are 28 to 33°C (82 to 92°F); stop feeding when the ambient temperature drops below about 21°C (70°F); and become dormant at temperatures below 13°C (55°F). During colder weather they excavate a depression called a “gator hole” along a waterway that they use during dormancy. In places where water level fluctuates, alligators dig themselves into hollows in the mud, which fill with water. These tunnels, often as long as 20 meters (65 feet), provide protection from weather extremes.
Their body structure, especially their legs and tail, gives them the ability to swim, run, walk, crawl, and even gallop on land. Upward-facing nostrils located at the end of their snout allow them to breathe air while the rest of their body is fully submerged.
Alligators are “cold-blooded;” they cannot regulate their own body temperature. Instead they assume the temperatures of their surrounding environment. They warm themselves by sunbathing, frequently on the banks of water bodies. On hot summer days they open their mouth to cool off, much like a dog pants when too warm.
Alligators have fairly poor eyesight. They have a “nictitating membrane” to protect their eyes so that they can see underwater. They hear with ears that are located behind their eyes and are very sensitive to vibrations in the water.
25 to 50 years
Historically alligators were depleted from many parts of their range as a result of commercial hunting and habitat loss to the point that many people believed this unique reptile would never recover. In 1967 the American alligator was listed as endangered under the U.S. Endangered Species Act (ESA). The species was considered in danger of extinction throughout all or a significant portion of its range. As the result of a cooperative effort among the U.S. Fish and Wildlife Service (FWS) and agencies in the southern states in the alligator ranges, these unique reptiles were saved. Under the ESA alligator hunting was prohibited, allowing the species to rebound in numbers in many areas where it had been depleted. As they began to make a comeback, states established alligator monitoring programs and used the information to ensure that numbers continued to increase. In 1987 the FWS pronounced the American alligator fully recovered and consequently removed the species from the list of endangered species.Today a multi-million dollar industry in alligator farms exists, in which alligators are captive-raised for their skin and meat.
Although the American alligator is now safe, some related animals—such as several species of crocodiles and caimans to which they have some resemblance—are still in trouble. For this reason, the FWS continues to protect the alligator under the ESA classification as “threatened due to similarity of appearance.” This enables the FWS to regulate the harvest of alligators and legal trade in the animals, their skins, and products made from them as part of efforts to prevent the illegal take and trafficking of endangered “look-alike” reptiles.
The main threat to alligators is loss and degradation of habitat due to development and agricultural and recreational use. In the Florida Everglades, alligator conservation depends on restoration of more predictable hydrological fluctuations that have been disrupted due to water management. Polluting runoff from agriculture that contains dioxins and mercury is also a threat.
Alligators are unique among reptiles for providing maternal care to their young. But even though the female aggressively defend her hatchlings, 80 percent of the young fall prey to raccoons, birds, otters, bobcats, snakes, large bass, and even to larger alligators,
Adopted as Florida’s state reptile in 1987, the American alligator is also the University of Florida’s mascot.