Olive ridley sea turtles have unusual nesting habits. For other sea turtle species, mothers file on to nesting beaches one by one over the course of nesting season, which can last months. Olive ridley sea turtles, like their Kemp’s ridley cousins, prefer to nest in groups. When it comes time to nest, they will gather off the beaches in groups, then come onshore all at once. They can number in the thousands. This event is known as an arribada, which means “arrival” in Spanish.

Even though arribadas seem like big parties, traveling in such numbers can put Olive ridley sea turtles at risk. Their populations are threatened by people capturing eggs and adults, especially during an arribada. Like other sea turtles, Olive ridley sea turtles are also threatened by marine debris—they can become entangled in fishing nets, accidentally ingest balloons or plastic bags and more. It’s so important to reduce the amount of plastic pollution entering the ocean so Olive ridley sea turtles have a healthy ecosystem in which to live.