Thursday, July 05, 2012

Alligators in Texas

The American alligator, Alligator mississippiensis, was facing extinction due to hunting and loss of habitat.  Originally alligators could be found as far north as New Jersey, south along the South Atlantic and Gulf Coast and inland up the Mississippi River to the convergence with the Arkansas River and west in Texas to the 100th meridian.  (San Angelo is just west of the 100th meridian.)  Today's smaller range is east to the Carolina's, west to Texas, and north into Arkansas.  Texas provided protection for alligators beginning in 1969 and the population has recovered such that it is no longer listed as an endangered species.

The American alligator is an amazing creature - a large reptile, armored with coarse scales ranging in length from 6-14 feet.  The head is large with large visible upper teeth along the long jaw line.

The front feet have five toes and the rear feet are webbed with four toes.  Alligators are semi-aquatic choosing to live in marshy bodies of water.  While they are more often found in fresh water, they tolerate brackish water also.  They are good swimmers and often float with just their eyes and nostrils above the water. They are able to run quickly over short distances on land.  I have never been fortunate to hear an alligator, but they can be very vocal.  Young alligators bark and adults may bellow, grunt, or hiss.

Carnivorous, alligators will eat any animal it can catch. The normal diet includes small mammals, waterbirds, snakes, fish, crustaceans, lizards, turtles, and even other alligators.  When human habitation coincides with alligator areas, small pets can also be part of the diet.  Fortunately, alligators usually avoid humans, but small children can be at risk when alligators are present.

In Texas, alligators brumate from mid-October until early March.  Brumation is similar to mammal hibernation, a dormant state for cold blooded animals.  A brumating reptile is lethargic, sometimes not moving at all during the cold season.  Brumation is not the sleep of hibernation rather a less active state where the metabolism slows so they don't need to eat.

After emerging from brumation, alligators breed and nest from March 1 through May 30.  Females remain close to their home territory, but males occupy ranges up to ten square miles.  The female builds a nest from local vegetation that may be as large as six feet across and several feet tall.  She lays eggs in the center of the mound and the heat from both the decaying vegetation and sunlight incubates the eggs.  Females lay over 35 eggs, which are about three inches in length.  Incubation lasts about 2 months and the female watches and defends the nest.  The young alligators "yip" when they hatch and the female helps dig them out of the nest.  Hatchlings are about 9 inches long and stay with their protective mothers for up to two years.

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