The American alligator is a marvel of efficiency. They are the largest reptile in North America and an apex predator. They spend much of their day sitting in the sun to help regulate their body temperature, since they are cold blooded. They are opportunistic feeders that hunt primarily by ambush. Sitting with just the top of their head above water they can appear like a floating log until something comes along. This way they do not burn up much energy hunting. Alligators are not picky and they will try and eat most anything that they can get into their mouths. They have existed in one form or another for over 150 million years, although in the late 1960s they were close to going extinct. Hunting, habitat loss and the predation of eggs forced the American alligator to be listed as an endangered species. It was removed in 1987 as there are now millions of alligators in the south eastern United States.