The alligator is an ancient creature which first appeared during the Oligocene epoch about 37 million years ago. Today there are two living alligator species: the American alligator - Alligator mississippiensis, and the Chinese alligator - Alligator sinensis. However, there are several extinct species of alligator are known from fossil remains.

Where do Alligators live?

Not to be confused with crocodiles, alligators are only native to the United States and China. In America they are found in the southeast United States: all of Florida and Louisiana, the southern parts of Georgia, Alabama and Mississippi, coastal South and North Carolina, Eastern Texas, the southeast corner of Oklahoma and the southern tip of Arkansas. The majority of American alligators inhabit the states of 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. 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.

Alligator behaviour

Large male alligators are solitary territorial animals, although smaller alligators can often be found in large numbers close to each other.

The mating season is in late spring. In April and May, alligators form so-called "bellowing choruses". Large groups of animals bellow together for a few minutes a few times a day, usually one-three hours after sunrise. The bellows of male American alligators are accompanied by powerful blasts of infrasound produced by sacs in their chins.

Another form of male display is a loud head-slap. Recently it was discovered that on spring nights alligators gather in large numbers for group courtship, the so-called 'alligator dances'.

In summer, 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 leaves 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).

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.

Baby alligators have an egg tooth that helps them get out of their egg during hatching time. 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 juveniles, increasing survival among the young alligators.

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