Although they do also nest alone, olive ridleys are known for their remarkable mass nestings, when many thousands of females congregate on the same beach; the event is known as an 'arribada', which is Spanish for 'mass arrival' (5). Males and females migrate from the feeding grounds and mating occurs just offshore of the beach (9). Usually at night, and coinciding their nesting with the high tide, females haul out on their natal beach and lay clutches that typically contain around 110 to 120 eggs (9). These astonishing mass nestings can involve up to 150,000 females (7) and there may be more than one arribada on a single beach; this overcrowding means that turtles are often crawling over each other to move up the beach and may even unearth other nests whilst digging their own (5). During one season a female may lay two to three clutches of eggs, returning to breed every few years (9). After around 50 to 60 days, the hatchlings emerge and make their chaotic dash to the sea (5). Predators such as jackals and crabs will feed on turtle eggs, whilst birds attack hatchlings on the beach and fish wait in the shallows (9). These arribadas probably function to increase hatchling survival by overwhelming predators with sheer numbers (5). Adult olive ridleys are carnivorous and feed on a wide variety of organisms including fish and molluscs (5); sometimes diving up to 150 metres in search of prey (7). Very little is known about the first years of life but juveniles probably spend a number of years floating on the ocean currents and feeding on planktonic organisms (10).