Arribadas

Some populations of Olive Ridley( one of the two species of the genus Lepidochelys , and a member of the family Cheloniidae) synchronize their nesting in mass emergences or ariibadas. The most dramatic aspect of the life history of the olive ridley is the habit of forming great nesting aggregations, generally known as "arribadas," Although not every adult olive ridley participates in these arribadas, the vast majority of them do. Individual olive ridleys may nest one, two or three times per season, typically producing 100-110 eggs on each occasion. The inter nesting interval is variable, but for most localities it is approximately 14 days for solitary nesters and 28 days for arribada nesters. The genus is also unique in that ridleys of both species commonly, and probably typically, nest each year, without intervening non-breeding seasons as shown by dermochelyids and other cheloniids. The ridleys nesting in an arribada could not be sustained by the productivity of immediately adjacent marine ecosystems, and the species is indeed migratory Millions of Olive Ridley ; emergent from South America and cross a long distance and nested in the Indian State of Orissa, the most important being Gahirmatha Beach and Bhitar Kanika.