SIZE: Males: length, to 15 feet; weight, 400 lbs. Females:
length, to 8 feet; weight, 160 lbs.
RANGE: Southern United States and Central America.
HABITAT: Edge of bodies of water; swamps, rivers and lakes.
DIET: Carnivore; fish, small mammals and birds. Young eat insects, worms and small fish.
LIFE SPAN: Little is know about longevity in the wild. There are records of 73-100 years in captivity.
STATUS: Formerly endangered, now threatened due to the protection given to them. Limited, licensed hunting is allowed in a few areas.
ADAPTATIONS:
ANATOMY: Average growth is one foot per year for the first six years. The whole body is covered with large, strong, ossified, horny plates. The large strong jaw has 80 teeth, and is used to capture, crush and dismember; however, the alligator cannot chew, so they swallow their food whole or in chunks. Often lose teeth in encounters with prey but they are quickly replaced. Each tooth contains a small replacement tooth within its pulp cavity and examination sometimes reveals a further tiny tooth ready to erupt within that. The tongue is fused to the floor of the mouth and can hardly move. They cannot swallow underwater.
AQUATIC ADAPTIONS: Eyes, ears and nostrils are near the
top of the head, with valves to close the ears and nostrils when
it is submerged. It normally lies in the water with only the top
of the head showing. Can stay underwater from 45-60 minutes. Toes
are joined at the base by webbing. They move most efficiently in
water; swimming with a serpentine movement of the body and stroke
of tail.
SENSES: Good binocular vision.
LOCOMOTION: Will slide on its belly, walk or gallop for short distances when out on the land. It is an excellent swimmer and uses its hindfeet as rudders in the water.
HEAT REGULATION: Ectothermic, primary source of body
heat is external. It lies on the banks to bask in the sun for
warmth and submerges itself underwater to cool off during the
heat of the day. Opens its mouth to keep warm also.
HABITS: Females are territorial and will guard and defend their nests. An adult will eat 20 lbs per week in hot weather, but no food during the winter. Males roar during the mating season, but the normal vocalization is a hiss.
REPRODUCTION: Mating occurs in open water. The female
then goes to the thickest part of the marsh to build a large nest
of muddy vegetation. A week later, she lays 30 to 70 eggs which
hatch 2 months later. Young use an egg tooth to help open the egg.
They then grunt, which stimulates the female to chew open the nest
and the 9 inch young escape to the water. The young eat insects,
worms, and small fish. They stay with their mother for 18 months.
MISC.: Comparison to crocodile: Alligators have a broader, blunter head and a shorter snout than crocodiles.