American alligators were nearly hunted to extinction in the 1950s and 1960s, and in 1967, officially were under protection of the Endangered Species Act. Twenty years later, the American alligator was delisted from endangered status because the population had fully recovered. Most people attribute this relatively quick recovery to the unique breeding behaviors of alligators.
Alligators breed in the spring. The female then builds a nest of mud and vegetation that is about three feet high and six feet in diameter. She lays 30 to 50 eggs and buries them in the rotting vegetation. The eggs are white, hard and slightly bigger than a large chicken egg. The nest provides heat — it is like a big compost pile and heats up naturally because of the decomposing vegetation. The alligator eggs respond to the temperature. If the maintained temperature of the nest is in the low 80s (degrees F), the hatchlings will be female. If the temperature hovers in the low 90s, they are male. For temperatures in between, the resulting hatchlings are a mixture of males and females.
The mother protects the nest from predators, such as raccoons, while the eggs are incubating. When the eggs hatch about 40 days later, the hatchlings make a noise and the mother digs them out of the nest. The hatchlings and mother will stay near the nest, and the mother will protect the hatchlings if they get into trouble and cry out. This protective behavior is very rare in modern reptiles, but it is thought to be common in certain dinosaur species.