American Alligator

Alligator mississipiensis Flamingo Campground, Everglades National Park

3-17-00 Photographed by: Gordon Atkins

Behavior Page

Organisms / Vertebrates / American Alligator

Descriptive Information

Field marks: The American Alligator is a long, slender, powerful, reptile who inhabits the waters of the southeastern United States. The alligator can be recognized by its short, blunt snout and large, forward eyes, which, along with its ears and nostrils lie in the same plane on the snout, allowing the entire animal to be submerged while leaving these organs out of the water. The upper teeth on the alligator close down outside the jaw when the mouth is closed but the bottom teeth are covered. This is one distinguishable characteristic between the American Alligator and its relative, the American Crocodile who displays the fourth bottom tooth when its mouth is closed. Alligators also have a large, powerful tail which oscillates sideways to aid in locomotion through the water. They have a very scaly skin and small, vertical bony plates on their dorsal side for defense. Alligator's have short, powerful limbs used mainly for terrestrial travel digging for which they use their sharp claws.

Size: Alligators range in size from 6 inches at birth to the record male length 19 ft. 2 inches (Louisiana in early 1900) as an adult. Most alligators are between 6 and 16 ft. long with any at over 12 ft. being rare. Properly nourished baby gators will grow at about a foot a year and even the adults continue to grow throughout life. Alligators Adult alligators weigh about 400-700 pounds but some can tip the scales at up around a thousand. A helpful little device used to approximate the length of a gator (It's not a good idea to walk up to a live one with your trusty Stanley tape measure) is to estimate the number of inches from the eyes to the nostrils. This is marginally the length in feet, form head to tail, of the gator.

Diet: An alligator will eat nearly anything it can overpower including poisonous snakes whose venom has apparently no affect on them. They have been known to take fish (particularly the alligator gar), birds, otters, deer and even other smaller alligators. Because their teeth are conical shape and are specialized for gripping they have to shake their larger prey around in their mouths in order to tear off pieces small enough to swallow. Their stomach does all their digestion and alligators have even been known to swallow rocks and sticks to aid in the churning and breakdown of meat.

General habitat: The American Alligator lives in or near aquatic bodies of water ranging form fresh to slightly brackish coastal marshlands but can also be found in salt water. Salt water inhabitancy is rare, however, because although it can be tolerated for a little while they are unable to survive in it for long periods of time . Alligators seem to prefer swamps, ponds, marshes and lakes because these spots are ideal for climate, food, sunning, and protection for their young.

Geographic range: The American Alligator's habitat extends from North Carolina down to southern Florida and then as far west as Texas. Other states which are inhabited by the alligator include Georgia, South Carolina, Louisiana, Arkansas, and Mississippi.

Reproduction: The point at which alligators reach sexual maturity is not governed by age so much as it is size. An alligator will usually become sexually mature at about six feet long and many times this growth will take ten to twelve years although it is quicker in captivity. The breeding season for gators starts in April and it is very much involved. Touching, rubbing, bubble blowing and vocalizations are a part of the courtship. Actual mating occurs in the water using a coitus method. Because male alligators are polygamous and may service up to ten partners in one season, they become very territorial and will defend their property fiercely. The female will begin to build a nest after fertilization where she can keep the eggs. She will lay 40-45 eggs at a time in late June or early July and they will take about 65 days to incubate. The female will defend her nest and her young for two to three years from their many predators and it isn't until the babies are at least four feet long that they will be free from predators with man being the exception.

Ecosystem(s) where observed: The most probable ecosystem of the Everglades where one could find the alligator would be the sawgrass marsh. The water would have to be high enough to support the alligator in both residence and food resource. Another possibility for a sighting would be in the cypress dome (usually only in the wet season, though). Although not likely, alligators sometimes pass through these areas to search for food and/or find water. The pinelands, coastal prairie, mahogany hammock, and marl prairie are all far too dry to support an alligators' needs.

Importance to the Everglades: The Everglades in central and southern Florida is a region composed of a wide variety of terrestrial and aquatic life with its success due in part to the behaviors of the American Alligator. During the wet season when water levels are at their peaks, female alligators will dig out holes in the banks of marshes and ponds. They unearth the vegetation and dirt and pile it around her site, creating an "alligator hoe." These holes will also contain dens for the alligator to 'live' in. Many times these holes will consist of trails which connect to other nearby marshes. Alligator holes are reused by other alligators and some can survive being past on and on for centuries. The holes are often marked by vegetation such as alligator flag that grows up and around the built up portions on the outside. The holes can range from from 7 to 20 feet in width and the water level is usually four feet deeper than the surrounding area. This added depth allows these holes to stay wet during the dry season after the sheet flow has drained through and it serves as a haven for birds who feed on the fish living in the holes. If these holes were not there to keep the water, the entire land would drain off and many animals, both marine and terrestrial, would die. The alligator is also important in preventing over population of other species. Because it will eat nearly anything of relative size that moves, the alligator almost single-handedly prevents any particular animal from overrunning the Everglades. Also, if there are too many gators and their food supply begins to run low, they will eat one another - keeping their own population in check. Baby alligators are also easy targets for prey by hawks, raccoons, wood storks, largemouth bass, herons, and other alligators but they will grow up to take these same predators as prey.

Personal Observations: While I observed the alligator in the Everglades over the course of our Spring Break trip in March 2000 I realized that the alligator is pretty lazy. Not that I blame it, but I doubt an alligator would move if it weren't for food, sunlight, or mating. The alligator is still quite fascinating to observe, though. I watched a number of them over the course of our trip and it seems that about 90% of their time is taken up "resting." And why shouldn't it be? An alligator has no real enemies except for man and when they are protected in the Everglades -- Hey, what else is there to do? One baby alligator I watched was my favorite. He was at Eco Pond on Saturday, March 18 and I watched him for nearly an hour. It was around 1:00 pm and he was looking for a meal. But, since he was so small and quite an inexperienced hunter he really was doing a bad job. First of all, he was stalking (if that's what you could call his obvious behavior) much too large of a meal for his sixteen inch body, a Common Moore Hen. Second, he was in a very shallow part of the pond (probably in part to avoid becoming a meal himself by an older brother) which would have enabled his prey to escape quickly to land and fly away. Also, the baby gator was making a lot of noise. He did do a few things right he swam to their downwind side so that they wouldn't be tipped off by his presence. He also rooted around in the mud and positioned sticks and mud on his back hopefully to make him seem all that ouch more hidden. It didn't work, the hens just swam right on past him and with a few threating gestures with their beaks he left them alone. I also watched another larger gator as he swam slowly, and quitely up to the shore. He lay mainly submerged with only his eyes, and nostrils out of the water. I was sitting close to his position on a rock wall on the bank talking with Joey Steffen when he lunged sideways very rapidly and struck -- mouth open -- to his right side about a foot away. He came up empty but his striking speed was amazing.

Works Cited:

Lodge, Thomas E. The Everglades Handbook. Understanding the Ecosystem. St. Lucie Press: Boca Raton, Florida. 1998.

Godwin, Mike. http://home.cfl.rr.com/gatorhole/

http://www.birminghamzoo.com/ao/reptile/amgator.htm

http://tqjunior.advanced.org/3715/Animal%20Reports/american_alligator.htm

http://www.csc.noaa.gov/otter/htmls/project/gator.htm

(This page developed by: Cameron Trubey)