An Alligator is a crocodilian in the genus Alligator of the family Alligatoridae. The name alligator is an anglicized form of the Spanish el lagarto (the lizard), the name by which early Spanish explorers and settlers in Florida called the alligator. There are two living alligator species: the American alligator (Alligator mississippiensis) and the Chinese alligator (Alligator sinensis).
[edit] Description
The alligator has been described as a 'living fossil from the age of reptiles, having survived on earth for 200 million years'.[1]
An average American alligator's weight and length is 800 pounds (360 kg) and 13 feet (4.0 m) long, but can grow to 14.5 feet (4.4 m) long[2] and weigh 1,000 pounds (450 kg)[3]. According to the Everglades National Park website, the largest alligator ever recorded in Florida was 17 feet 5 inches (5.3 m), although according to the Florida Fish and Wildlife Conservation Commission web site the Florida state record for length is a 14 feet 5/8 inches (4.28 m) male from Lake Monroe in Seminole County[citation needed]. The Chinese alligator is smaller, rarely exceeding 7 feet (2.1 m) in length. Speeds have been clocked by alligators of up to 27 miles per hour (43 km/h)[citation needed], making one of the fastest large reptiles on the planet.
An alligator's lifespan is usually estimated in the range of 50 years or more. A specimen named Muja has resided in the Belgrade Zoo in Serbia since 1937, making it at least 71 years old. Another specimen, Čabulītis, in Riga Zoo, Latvia died in 2007 being more than 75 years old.
[edit] Habitat
Alligators are native to only two countries: the United States and China.
American alligators are found in the southeastern United States: all of Florida and Louisiana, the southern parts of Georgia, Alabama and Mississippi, coastal South and North Carolina, Eastern Texas, the southeastern corner of Oklahoma and the southern tip of Arkansas. The majority of American alligators inhabit Florida and Louisiana, with over a million alligators in each state. American alligators live in freshwater environments, such as ponds, marshes, wetlands, rivers, lakes, and swamps, as well as brackish environments[citation needed]. Southern Florida is the only place where both alligators and crocodiles live side by side.
The Chinese alligator currently is found only in the Yangtze River valley and is extremely endangered, with only a few dozen believed to be left in the wild. Indeed, far more Chinese alligators live in zoos around the world than can be found in the wild. Rockefeller Wildlife Refuge in southern Louisiana has several in captivity in an attempt to preserve the species. Miami MetroZoo in Florida also has a breeding pair of Chinese alligators.
[edit] Behavior
Large male alligators are solitary, territorial animals. Smaller alligators can often be found in large numbers in close proximity to each other. The largest of the species (both males and females), will defend prime territory; smaller alligators have a higher tolerance of other alligators within a similar size class.
Although alligators have heavy bodies and slow metabolisms, they are capable of short bursts of speed, especially in very short lunges. Alligators' main prey are smaller animals that they can kill and eat with a single bite. Alligators may kill larger prey by grabbing it and dragging it in the water to drown. Alligators consume food that cannot be eaten in one bite by allowing it to rot or by biting and then spinning or convulsing wildly until bite-size chunks are torn off. This is referred to as the "death roll." A hard-wired response developed over millions of years of evolution, even juvenile alligators execute death rolls when presented with chunks of meat. Critical to the alligator's ability to initiate a death roll, the tail must flex to a significant angle relative to its body. Immobilizing an alligator's tail incapacitates its ability to begin a death roll.[4]
Most of the muscle in an alligator's jaw is intended for biting and gripping prey. The muscles that close the jaws are exceptionally powerful, however the muscles for opening their jaws are relatively weak in comparison. As a result, an adult man can hold an alligator's jaw shut with his bare hands. In general, a strip of duct tape is enough to prevent an adult alligator from opening its jaws and is one of the most common methods used when alligators are to be captured and/or transported.[5] Alligators are generally timid towards humans and tend to walk or swim away if one approaches. Unfortunately, this has led some people to the practice of approaching alligators and their nests in a way that may provoke the animals into attacking. Feeding of alligators found within 500 feet of residential areas is prohibited.[citation needed]; further away is not illegal, but still not recommended. If fed, the alligators will eventually lose their fear of humans and may, in turn, choose to approach human settlements rather than moving away.[6]
[edit] Diet
 | This section is missing citations or needs footnotes. Using inline citations helps guard against copyright violations and factual inaccuracies. (July 2008) |
When young they eat fish, insects, snails, crustaceans, and worms. As they grow, they take progressively larger prey items, including larger fish such as gar, turtles, various mammals, birds, antelope and other reptiles. Their stomachs also often contain gastroliths. They will even consume carrion if they are sufficiently hungry. Adult alligators can take razorbacks and deer and are well known to kill and eat smaller alligators. In some cases, larger alligators have been known to hunt the Florida panther and black bears, making it the apex predator throughout its distribution. As humans encroach onto their habitat, attacks on humans are few but not unknown. Alligators, unlike the large crocodiles, do not immediately regard a human upon encounter as prey, but may still attack in self-defense if provoked.
[edit] Reproduction
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Alligators generally mature at a length of 6 feet (1.8 m). The mating season is in early spring. The female builds a nest of vegetation where the decomposition of the vegetation provides the heat needed to incubate the eggs. The sex of the offspring is determined by the temperature in the nest and is fixed within 7 to 21 days of the start of incubation. Incubation temperatures of 86 °F (30 °C) or lower produce a clutch of females; those of 93 °F (34 °C) or higher produce entirely males. Nests constructed on levees are hotter than those constructed on wet marsh and, thus, the former tend to produce males and the latter, females. The natural sex ratio at hatching is five females to one male. Females hatched from eggs incubated at 86 °F (30 °C) weigh significantly more than males hatched from eggs incubated at 93 °F (34 °C)[7]. The mother will defend the nest from predators and will assist the hatchlings to water. She will provide protection to the young for about a year if they remain in the area. The largest threat to the young are adult alligators. Predation by adults on young can account for a mortality rate of up to fifty percent in the first year. In the past, immediately following the outlawing of alligator hunting, populations rebounded quickly due to the suppressed number of adults preying upon the new recruits, increasing survival among the young alligators.
Some alligators are missing inhibited gene for melanin, which makes them albino. These alligators are extremely rare and practically impossible to find in the wild. They could survive only in captivity. As with all albino animals, they are very vulnerable to the sun and predators.[8]
