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Olive Ridley Turtles

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 Olive Ridley

Olive Ridley Hatchling
Lepidochelys olivacea

  Tortuga Lora

This is one of the smallest turtles, measuring 60 to 75 cm long and weighing 35 to 40 Kg. Their shells are drab olive green and they are known to nest in solitary fashion on more than forty beaches on the Pacific coast of Costa Rica between the months of June and December.

Tortuga Lora

Nesting & Food

The Olive Ridley is the only species of turtle that exhibits the synchronized mass nesting phenomenon known as "Arribadas". These arribadas occur at Nancite in the rainy season from May to December and in Ostional all year round.

Their main food source is shrimp, crustacea and other invertebrates such as squid.


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Costa Rica's Olive Ridley Turtles

PLAYA OSTIONAL. This beach, made famous by Dr. Douglas Robinson, is located at the village of Ostional north of Punta Guiones close to Playa Nosara. Access is via Nicoya to Nosara and from Santa Cruz. The final stretches are advisably accessible via four-wheel drive vehicles in the rainy season.

This is the most important Arribada beach in the world and is the location of the only legal turtle egg harvest. Due to the fact that such a large proportion of the eggs are lost to natural causes, Ostional's local development association (ADIO) controls the legal harvest and sale of about 1,000,000 eggs a month.

The beach area and marine waters are protected by the Ostional National Wildlife Refuge, and the project is overseen by strict scientific control to assure that no damage is being done to the turtle population.

It is generally accepted that this is one of the truly sustainable yield projects in the world, benefiting both man and turtle.  §


Playa Ostional

Ostional National Wildlife Refuge 

PLAYA NANCITE. This 1km long beach is located in Santa Rosa National Park. Olive Ridley and other turtles that nest here are totally protected. After Ostional this is the second most important nesting beach in the world.

The occurence of the arribada is directly related to the lunar cycle, normally starting with the last quarter of the moon but may occur with the first quarter. It is impossible to predict the exact time or possibility of an arribada but the best months are between May and December. Access to Nancite is through the park via Playa Naranjo and is possible only on foot.  §

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Five of the world's seven species of marine turtles come to nest on the beaches of Costa Rica. The Green Turtle (Chelonia mydas ) nests on the Caribbean coast and the Black Turtle or "Tora" and Olive Ridley or "Lora" (Lepidochelys olivacea) nest on the Pacific coast. The Leatherback or "Baula" (Dermochelys coriacea) and the Hawksbill or "Carey" (Eretmochelys imbricata) nest on both coasts. There have been a few reports of Loggerhead or "Cabezona" (Caretta caretta) nesting on the Caribbean coast but none on the Pacific.

On both coasts one may find many beaches where turtles nest in solitary fashion which means that between one and twenty turtles may nest on any given night. There are at least forty beaches in this category. Due to their low numbers, it is difficult to observe turtles nesting on these beaches.

In the second category are the beaches where intensive nesting takes place. This means that between twenty and one hundred turtles may nest on a given night. These beaches are ideal for observing turtles nesting. Among beaches in this category are, Playa Tortuguero (Green Turtles and Leatherbacks) and Playa Grande and Playa Naranjo (Leatherbacks).

In the third category are those beaches where MASSIVE nesting takes place. This phenomenon, called "Arribada", is the synchronized nesting of thousands of turtles for between three and nine days. The most important of these beaches are Ostional and Nancite.

NOAA Olive Ridley Info