Alligators generally mature at a length of 6 feet (1.8 m). 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".
Alligators are the only non-avian species shown to have one-way breathing, although presumably similar measurements for other crocodilians (not yet done) would show unidirectional air flow in them as well. All other non-avian amnionts have dead-end breathing. In dead-end breathing the air flows into the lungs through branching bronchi which terminate in small dead-end chambers called alveoli. The air moves in both directions through the bronchi. In alligators the air makes a circuit through the lungs moving in only one direction through the bronchi. The air first enters the outer branch moves through the lungs in small tubes called parabronchi and exits the lung through the inner branch. The parabronchi are where the oxygen exchange takes place.
They have a muscular flat tail that propels them while swimming.
Albino alligators have a non-functional gene for melanin, which makes them albino. The is the common trait of all albino vertebrates.
In leucistic alligators all of the pigment genes are defective not just the melanin gene. This makes them white white with blue eyes. The Aquarium of the Americas in New Orleans has leucistic alligators found in a Louisiana swamp in 1987.