Olive Ridley Arribada

An olive ridley (Lepidochelys olivacea) “arribada” at the Ostional Wildlife Refuge on the Costa Rican Pacific coast, 2005. The largest mass synchronized nesting phenomenon thus far recorded in Ostional took place in November 1995 when a calculated 500,000 females came ashore. Credit: Zoraida Díaz

June 12, 2026