Alligators are primarily carnivores. Their prey consists of whatever is abundant and easily accessible ranging from amphibians and fish to birds and mammals. What an alligator chooses to eat relies heavily upon availability, vulnerability, and size of prey. The size and sex of the alligator also play a role in the alligator diet. 
Alligator Diet Varies with Habitat
The habitat in which an alligator lives is the primary determinant of what it eats. For example, the primary diet for alligators in Florida and northern Louisiana is fish and turtles. Alligators in suburban areas will feed on domestic pets. Those is rural areas will prey upon calves, hogs, goats, and foals. Larger alligators have been known to feed on cattle and horses.  They are also cannibals and will feed upon other alligators. Up to 5% of juvenile mortality is attributed to becoming the meal of another alligator. 
Alligator Diet Varies with Size
Though the alligator is an opportunist feeder, what they eat varies with their size. Hatchlings feed primarily upon crustaceans, snails, and small fish. The size of the prey grows larger as the alligator matures. Subadults primarily feed upon crustaceans, fish, small mammals, and birds. Mature adults primarily eat fish, turtles, birds, and mammals. 
Alligator Diet Varies with Sex
A Florida study designed to determine an alligator’s eating habits examined the stomach contents of more than 350 American alligators and found that the alligator diet also seems to vary with sex. In the same populations, female alligators consumed significantly more mammals, while male alligators consumed more reptiles. 
Do Alligators Eat People?
Human attacks are rare, but they do happen. As mentioned, an alligator will eat anything that makes itself available. Feeding alligators is a dangerous activity that leaves humans vulnerable to attacks. An alligator will become aggressive once they associate a human with food. Swimming in areas that are known to have alligators put you at extreme risk of being attacked. Anytime that humans encroach on alligator habitat increases the risk of being attacked. 
How Much Do They Eat?
Did you know that a 100-pound dog will eat more in a year than an 800-pound alligator?  That’s because they are ectotherms relying on external heat sources to regulate body temperature. When the temperature drops, so does their metabolism, which means that they do not require as much food energy as an endotherm. This means that an adult alligator may only need to eat a few times per week. 
When Do Alligators Eat?
Alligators primarily feed at dusk or during the night. Their feeding habits also depend on the temperature. Because they are ectotherms, they are most active feeders at a time of year when their metabolism is highest at temperatures between 82°F-92°F. They will generally stop feeding if the temperature drops below 70°F.  They will become dormant at temperatures below 55°F. 
How Alligators Eat
Once an alligator kills an animal for food, it usually consumes it immediately. However, if the prey is large and cannot be swallowed whole, it may be placed underwater to be eaten when the animal has rotted. The teeth of an alligator are designed to crush prey and tearing chunks from dead animals may be difficult for these reptiles. 
University of Florida; Rice N.
Diet and Condition of American Alligators in Three Central Florida Lakes
 Florida Game and Fresh Water Fish Commission; Woodward A.
Alligators: Food Habits
 Florida Game and Freshwater Fish Commission; Delany, M.
American Alligator Food Habits in Central Florida
 Savannah River Ecology Laboratory
Alligators Are Just Being Aligators
 Savannah River Ecology Laboratory
American Alligator (Alligator Mississippiensis)
 Texas A&M Agrilife
Texas Parks and Wildlife: Gator Facts
Florida Fish and Wildlife Conservation Commission
Reptiles: Alligator: Alligator Mississippiensis
 University of Florida-IFAS
Living with Alligators: A Florida Reality