Adaptations of the American crocodile are both behavioral and physical. Behaviorally, they are characterized as being shy, which saves them from their main predators--humans. Physically, they are cold-blooded and have adapted to a variety of foods.
American crocodiles are solitary, which minimizes their conflict with both humans and other crocodiles. They will attack aggressively if threatened. In South Florida, American crocodiles have adapted by becoming desensitized to humans. There, they are considered a "nuisance" animal, though they are still naturally aggressive when provoked. According to Crocodopolis.net, there's only one record of a wild crocodile killing a human, and this death occurred after the man cruelly provoked the creature.
American crocodiles have adapted to eating a wide variety of foods. They are gray-green in color, which allows them to blend into the brackish waters they inhabit. They hunt by lying motionless until prey comes along, usually fish, crustaceans or turtles. They attack their prey with a sudden ambush followed by a "death roll," in which they roll in the water until the prey dies. Crocodiles have also learned to regurgitate bits of food to attract more prey. Nonetheless, their cold-blooded metabolism allows them to survive for long periods between feedings.
American crocodiles can swim as fast as 20 miles per hour for a short period. They swim fast to catch prey and to avoid predators. They can also walk on dry land and gallop as fast as 10 miles per hour.