Alligators inhabit fresh to slightly brackish aquatic habitats. These habitats include marshes, swamps, creeks, rivers, lakes and ponds.
Males grow larger than females, although growth rate is similar up to approximately 3 1/2 feet in length. Sexual maturity of females in the wild is usually reached at a length of 6 1/2 feet and an age of 9 to 10 years in Louisiana.
Sexual maturitv is not reached until 18 to 19 years in North Carolina (still 6 1/2 feet in length). The alligator, like all reptiles, is a cold-blooded animal, and the difference in age to reach maturity is related to temperature-dependent growth.
Optimum growth occurs at temperatures between 85 and 91°F. No apparent growth takes place below 70°F, while temperatures above 93°F cause severe metabolic stress and can cause death. Alligators eat almost anything.
Research shows that young alligators primarily consume invertebrates like crayfish and insects. As they grow, fish are included in their diet. For adult alligators, mammals such as muskrats and nutria become more important in the diet.
Larger alligators even consume birds and other reptiles (including smaller alligators). Carrion is consumed whenever available. In general, the alligator’s natural diet is very high in protein and low in fat.
Alligator courtship and breeding correlates with air temperature and can occur between April and July depending on weather conditions. Courtship and breeding occur in deep (at least 6 feet), open water. Courtship behavior includes vigorous swimming and bellowing activity.
Both males and females bellow, but the male bellow is much more bass and vocal than that of the female. An alligator bellows with its mouth partially open, its head held at a 30- to 40-degree angle to the surface of the water, and its body submerged except for its tail which is arched above the water.
Most courtship occurs just after sunrise and takes about 45 minutes from precopulatory behavior through first copulation. Repeated copulation is commonly observed. After courtship and mating, females select and move to isolated ponds surrounded by dense vegetation for nesting.
Nesting occurs about two or three weeks after mating, usually June through July, depending on temperature. Nest building and egg laying occur at night. Females build nests by raking surrounding vegetation and soil into a mound.
A female may start several nests before a single nest is successfully completed. Twenty to 60 eggs are laid from the top into the center of the mound. All eggs are deposited at one time. When egg laying is completed the female covers the nest with about one foot of vegetation and remains nearby to guard nest from would-be predators..
In any given year nesting activity usually occurs within a two-week period. Nesting occurs only once a year and not all females nest every year. Warm summertime temperatures combined with heat generated from decaying mound vegetation maintain temperatures between 75 and 91°F and relative humidities of 94 to 99 percent in the nest.
The eggs hatch in 65 days if temperature in the nest is consistently above 86°F. The young make grunting or peeping sounds after hatching and the female often claws open the nest to help release them. Hatching success is generally less than 60 percent.
Research done in Louisiana suggests that survival of young alligators to four feet long averages 17 percent or less. After an alligator reaches 4 feet in length it has few enemies other than larger alligators and man. Growth rates in the wild vary considerably, with temperature and food availability as the most influential factors.
Females do not move or migrate over long distances once they have reached breeding age and prefer heavily vegetated marsh-type habitat. Males move around extensively but prefer to establish territories in areas of open water. Males longer than 9 feet are the most successful breeders probably because of little understood behaviors related to social dominance.
Author:
Michael P. Masser
