Ascension Island is perhaps best known for large numbers of Green Turtles that visit between November and June each year. They heave themselves up the same beaches on which they were born to lay their eggs. A few months later, their hatchlings emerge from their sand nests and scurry towards relative safety of the ocean. Many fall prey to scavenging frigate birds and other predators before they reach the water and even once in the sea they are at risk from the many predators patrolling off shore. However, those who survive return decades later to breed. There are also varied species of land and coastal crabs.