Loggerhead sea turtles nest on the sandy beaches. Other predators include tunas, sharks, swordfish, sea turtles and penguins. Endangered sea turtles nest on white sand beaches. Its diet includes mammals, birds, amphibians, fish, snakes, small turtles, and small alligators. The leatherback has several characteristics that distinguish it from other sea turtles. The date of separation of turtles and birds and crocodiles was estimated to be . It is absent in both turtles and snakes. It is the least endangered of all of the sea turtles. Most species of sea turtles hatch at night. The hawksbill's appearance is similar to that of other marine turtles. Fibropapillomatosis disease causes tumors in sea turtles. These countries have strong laws against keeping alligator snapping turtles without permission. Mating behaviour is similar to other marine turtles. There is considerable poaching of turtles and other marine life. This smaller group consists primarily of various freshwater turtles.