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Olive Ridley Turtle
Olive Ridley Turtle



Olive Ridley Turtle
Olive Ridley Nesting





Leatherback Turtle
Leatherback Turtle





Pacific Green Turtle
Pacific Green Turtle




Hawksbill Turtle
Hawksbill Turtle
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Turtles of Costa Rica
By Anny Chaves Quirós and Leslie A. du Toit, Ph.D, Douglas Robinson Marine Turtle Research Center

Four of the world's seven species of marine turtles nest on the Pacific coast of Costa Rica -- the Pacific Green (Chelonia mydas) or "negra," Leatherback (Dermochelys coriacea) or "baula" or "canal," Hawksbill (Eretmochelys imbricata) or "carey," and the Olive Ridley (Lepidochelys olivacea) or "lora" or "carpintera." Forty-seven beaches on the Pacific coast have been identified as having turtle nesting activity.

OLIVE RIDLEY or "LORA" (Leipidochelys olivacea)

The Olive Ridley or, "Lora" or "Carpintera," is the smallest of the species. The carapace length may be between two and two and a half feet. And the color is dark olive green to black. The weight may be between 75 and 85 lbs. The diet is principally comprised of shrimp, crustaceans and other marine invertebrates. After nesting, these animals migrate to deeper waters while staying relatively close to the coast and spending a large proportion of the time on the surface. Following the primary dietary source of shrimp, coastal migration takes place between Mexico and Chile. However, there does appear to be a resident population along the Costa Rican coast. This species is the most abundant off the Pacific coast of Costa Rica and nesting takes place along the whole length of the country on 48 of the 51 beaches identified as suitable for this activity.

The nesting population, where solitary nesting is concerned, has been estimated at between 4,500 and 5,000 individuals. Taking into account the Arribada beaches, the population is estimated at 750,000. The most important nesting beach is at Ostional, situated in the Ostional National Wildlife Refuge (Refugio Nacional de Vida Silvestre Ostional). The Nosara beach, located to the south of Ostional, is occasionally used during the large Arribadas by the same nesters of Ostional.

At Ostional, the Arribadas -- massive turtle nestings and egg layings -- occur on a lunar cycle of approximately 28 days. The majority occur around the last quarter of the cycle although this event may take place at any time including the full moon and two Arribadas (first and last quarter) may occur in the same month. The size and duration of the Arribadas varies between the dry and wet seasons. Those occurring in the dry season of January to April tend to be smaller (approximately 5,000 turtles) and of shorter duration (less than four days). In the wet season of May to December, up to 300,000 turtles may lay over a period of eight to 10 days. On a number of occasions between August and October, two Arribadas of 10 days each have occurred in the same month. This results in continuous activity during the month with a few days of lower activity and two peaks of maximum nesting.

This turtle is principally threatened by incidental capture in shrimp nets, on the long-lines off the coast and the illegal poaching of the eggs. On the Pacific beaches where solitary nesting takes place, it is estimated that human poaching results in the destruction of between 80 and 100 percent of the nests depending on the accessibility of the beach.

LEATHERBACK TURTLE or "BAULA" (Dermochelys coriacea)

The Leatherback turtle is the largest marine turtle in the world. There have been reports of specimens reaching nine feet and a weight of 1,900 lbs. The leatherback turtle, as opposed to other species, does not have a hard shell with scoots but is firm but pliable like thick leather. The shell has seven longitudinal ridges, and is colored black or dark gray with white spots. There is a difference in the size of individuals on the Pacific coast as opposed to the Caribbean, those on the Pacific being smaller.

The jaws, or mandibles, are strong, sharp and well-adapted to their diet, which basically consists of gelatinous organisms such as jellyfish. The range of these turtles is wide. They are known to be able to withstand extremely cold water and can therefore be found anywhere from the tropics to the poles. Their ability to auto-regulate their body temperature is due to a mechanism known as gigantothermia, which is believed to have been used by dinosaurs. They are known to be able to dive to great depths for long periods. On the Pacific coast, between Guanacaste and the Osa peninsula, the leatherbacks nest between October and February. The most important beaches are Playa Grande, Playa Langosta and Playa Naranjo. Eight beaches have been identified within the study area.

The Leatherback may nest approximately four times a season, laying between 50 and 80 eggs the size of billiard balls, as well a large number of smaller, infertile eggs. Although she may lay four times a season, there have been reports of turtles laying up to nine times. The incubation period for this species is approximately 60 days. As a great number of nesting takes place outside of protected areas, most of the nests are poached by humans. Poaching and ocean contamination constitute the major negative impact on this species. A significant cause of Leatherback mortality can be attributed to the ingestion of clear plastic products as they appear similar to jellyfish in the ocean. The meat of this turtle is not consumed due to its foul taste.

The population of Leatherbacks has diminished drastically in the last ten years. In Playa Grande in 1988, it was possible to observe up to 80 nesting females a night. Currently, approximately 100 turtles are observed throughout the six-month nesting season. At all other beaches, nesting occurs on a solitary basis. The possibility of observing this giant reptile nesting has become a rare event.

PACIFIC GREEN (BLACK) TURTLE or "NEGRA" (Chelonia Mydas)

The green turtle is a large animal whose carapace may reach a length of four and a half feet and weigh 750 lbs. Although found in all the oceans, many of the colonies have been decimated to a point of disappearance.

Known locally as "Tortuga Negra, Prieta or Tora", it is smaller than the Atlantic specimens. This turtle feeds on sea grasses, mangrove roots and invertebrates. Little is known of this species in Costa Rica, but 15 beaches have been identified as nesting sites. Not enough is known to determine the nesting season.

When nesting (solitary only), the female tends towards the top of the dunes and prefers doing so in the vegetation. Because she is easily disturbed by the slightest noise or light, it is necessary to exercise extreme caution while viewing so as not to affect the reproductive behavior. There is not enough information to determine the state of the population in Costa Rica. The most important beaches are Playa Huevos and Playa Cabuyal in the Golfo de Papagayo, where up to 20 nests have been reported in one week. Reports at other beaches have been sporadic.

For the quality of its meat, this species has been preferred throughout its distribution range. It has been heavily exploited for centuries and is still done so today. This has resulted in a marked decrease in the size of populations worldwide. Due to the extreme measures of protection, it may be said that the effort has stopped the population decline and at this moment the population appears stable. However, as has been demonstrated, marine turtles are susceptible to pressure and any management should be undertaken with due care so as to avoid the total loss of nesting colonies as has occurred in other parts of the world.

HAWKSBILL TURTLE or "CAREY" (Eretmochelys imbricata)

The Hawksbill is relatively small. Its shell, or carapace, rarely exceeds two and a half feet in length and may weigh up to 130 lbs. The carapace differs from other turtles in that the scoots are thicker and overlap (imbricate). The head is elongated terminating in a sharp bony beak ideally suited to its eating habits. Its distribution is typically tropical, both for nesting and foraging. The diet consists of marine sponges associated with tropical coral reefs.

The nesting is solitary and preferably associated with small beaches surrounded by rocky outcrops, although nesting may take place on larger beaches. On the Pacific coast, Hawksbills may rarely be observed swimming near coral reefs such as those near Golfo de Papagayo, Cabo Blanco and Isla del Caño. The sighting of a female nesting constitutes an extraordinary and rare event as the adult population has been severely decimated.

The Hawksbill is the most threatened of the species due to the high price of its shell, which is used internationally in jewelry fabrication. Although the sale of this product is totally illegal in Costa Rica and the world, it is common to find articles for sale to tourists on the street.

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