The nesting of Sea Turtles is one of natures amazing spectacles. Green Turtles nest along the beaches of Tortuguero National Park from July to October.
Leatherbacks nest frequently along the Caribbean coast and at Las Baulas National Park in Guanacaste from February to June. Hawksbill and Loggerheads, less common, nest along the Caribbean during the summer months.
The Olive Ridley nest in Ostional in Guanacaste, coming ashore in large numbers for several days each month from August to September.

Sea Turtles are most frequently seen when the females come ashore to deposit their eggs on beaches usually at night. Only 1 of 5000 Sea Turtles are going to be adults, so it is really important that people do not disturb them while digging the holes in the sand to put their eggs in. No bright flash lights please!

The Leatherback Turtle by Pulse Planet
They'll grow up to be the largest reptiles in the world. But tonight, on the Pacific beaches of Costa Rica, hundreds of Leatherback Sea Turtle babies, only four inches long, will hatch out of eggs the size of golfballs and run out to the sea. I'm Jim Metzner, and this is the Pulse of the Planet, presented by the American Museum of Natural History.
On January nights, the Costa Rican beaches are swarming with Leatherback Sea Turtles. The huge adult females, who are six feet long and weigh one ton, are busy digging their nests and laying their eggs, while tiny hatchlings are digging their way out of their nests and racing to the shore. And, according to Steven Morreale of Cornell University, "It's really an exciting time to be on the beach. It's just great." Mr. Morreale has often witnessed the birth of a Leatherback Sea Turtle baby. "It digs itself out of the nest, comes out, looks around, almost always night time, because if they come in the day, it's way too hot. They get a fix on where water is and then they all run down to the surf. So you can see as many as a hundred hatchling turtles all following each other, running down to the surfline. They're like little windup toys. Their little flippers are paddling away and they use that to propel themselves across the sand. And they head out into the surf, and actually that's the last time we see them for up to many, many years. And maybe, we'll never see them again. If they're males, they could go to the ocean and spend their entire life in the ocean. They could be as much as a hundred years, and we'd never know anything about that individual."

Turtle Species of Costa Rica

Loggerhead (Tortuguero, Caribbean)
Olive Ridley Turtle (Guanacaste Pacific Coast)
Leatherback Sea Turtle (Pacific and Atlantic Coast)
Hawksbill Turtle (Pacific and Atlantic Coast)
Green Turtle (Atlantic Coast)
Pacific Green Turtle ( Pacific Coast )

Several of Guanacaste's coastal national parks protect critical sea turtle nesting beaches. Santa Rosa National Park, the oldest in the region, is home to two of these beaches, Naranjo and Nancite ­ but both are difficult to get to because of poor road conditions. The seven-mile dirt road from the park's administrative buildings to Naranjo Beach is normally passable only in the dry season with a four-wheel drive vehicle (check with the park service before attempting this drive). Nancite Beach is restricted because of turtle nesting research programs, and advance permission is required to visit this beach, which involves a difficult hike from Playa Naranjo.

However, Guanacaste's other two protected beaches have relatively easy access.

A newcomer to the list of Costa Rican national parks, Las Baulas Marine National Park was created to protect two important nesting beaches for the Giant Leatherback Sea Turtle (Dermochelys coriacea), as well as conserve offshore areas where these large marine reptiles spend their days during the breeding season. Leatherbacks, known as baulas in Costa Rica, are the largest of the world's seven species of sea turtles, averaging 350 kg. (772 lbs.) and measuring more than 1.5 m. (about 5 ft.) in length. Watching one of these great ancient beasts come ashore at night to continue the age-old tradition of nesting in tropical sands is a very moving experience for most people, although others find the two-hour process a bit more than their patience and interest can tolerate. In Costa Rica, this species can be found nesting at a number of beaches on both coasts, however, two of the more heavily used beaches are Playa Grande (Big Beach) and Playa Langosta (Lobster Beach), to the north and south, respectively, of Tamarindo Beach. Together, the aforementioned two beaches make up Las Baulas Marine National Park.

The nesting season at Las Baulas extends from October through February. All visitors on the beach at night must be accompanied by a certified local guide (available at the entrance to the beach).

When away from their breeding sites, leatherbacks range widely throughout the world's oceans searching for their principal food, jellyfish.

Further south on the Guanacaste coastline is Ostional National Wildlife Refuge. This refuge was designed to safeguard a major nesting beach for Pacific Ridley Sea Turtles (Lepidochelys olivacea), along with the adjacent offshore area.

Several times a year, female turtles come ashore in such numbers that the sandy beach begins to resemble a stretch of rocky seashore. These mass nesting episodes are locally referred to as arribadas, or arrivals. One of these events can last from two to eight days with most nesting taking place at night. Locals will tell you that the arribadas begin three or four nights after the full moon, and this is typically the case in months when relatively small numbers of individuals nest. But during the peak nesting season (July through November) when more than 100,000 nests may be made during a single arribada, any correlation with phases of the moon or the tides breaks down completely. What triggers the mass nesting is still a mystery.

Scientists suggest that this species produces a superabundance of nests as a strategy for survival against predators. By laying so many eggs in just a few nights (a million or more during a large arribada) it is unlikely that local natural predators could possibly consume them all. Likewise, when the surviving eggs hatch and the young turtles scramble down the beach to the ocean, if thousands of them are doing this at more or less the same time, then some percentage of them ought to escape the variety of hungry predators that range from crabs to coyotes. However, natural predators are no longer the only threat facing each new generation of sea turtles. The creation of the Ostional National Wildlife Refuge is a wonderful example of the "if you can't beat 'em, join 'em" philosophy in conservation. For many years, the wholesale ransacking of turtle nests for eggs was a seasonal activity indulged in by people from all over the region, and even from as far away as San José. The widespread belief that consumption of turtle eggs produces aphrodisiacal effects has given them popular demand as bocas (snacks served as appetizers in local cantinas). Hampered by insufficient funding to adequately patrol the beach at Ostional, while at the same time needing the support of the local villagers, wildlife authorities proposed a new scheme with the declaration of the refuge. The proposal was that Ostional residents, and only Ostional residents, would be granted permission to harvest a limited number of eggs during the first two nights of each nesting period. These eggs could then be sold only to bars with licenses to serve turtle eggs. The idea was to get the local populace to function as a police force to safeguard their own interests and protect the later nests at the same time, since the later nests have a better chance of success (early nests are often inadvertently excavated by turtles arriving later on during an arribada).

This novel policy has generated much debate, but it seems to be working effectively. Vehicular access to Ostional is somewhat challenging, and a four-wheel-drive vehicle with good clearance is definitely recommended, especially if going in the wet season when the bulk of the sea turtle nesting occurs. Nonetheless, this beach is far more accessible than the only other beach in the country where this phenomenon occurs, Nancite Beach in Santa Rosa National Park. Ostional can be reached from either the town of Santa Cruz or Nicoya (both situated on the main highway that runs down the middle of the Nicoya Peninsula), and following a series of gravel and dirt roads to the coast (at Playa Junquillal if coming from Santa Cruz, or Playa Nosara if coming from Nicoya) and continuing south or north, respectively, until arriving at Ostional. Although more direct, the route via Nicoya-Nosara involves fording a river which can be impassable at times in the rainy season.

Turtle Watching  

Few places in the world have as many sea-turtle nesting sites as Costa Rica . Along both coasts five species of these huge marine reptiles come ashore at specific times of the year to dig nests in the sand and lay their eggs. It is an impressive thing to see, the pilgrimage of a sea creature back to the land its ancestors left a hundred million years ago.

Among the species of sea turtles that nest on Costa Rica 's beaches are:

Olive Ridley turtles

tend to lay eggs simultaneously, so you can see hundreds of turtles on the same night.

Leatherbach turtle

, world's largest marine turtle, can exceed 540 kg (1180 lbs). It comes to shore to lay it's eggs; this process can take many hours. The female drags it's almost 1000 pounds slowly from the ocean to a safe place in the sand; there it digs a deep whole. Then it returns to the sea. Unfortunately, leatherback turtle eggs are among the most desirable turtle eggs, mistakenly believed by many to have potent aphrodisiac power.

Loggerhead turtles (Caretta caretta)

come to the beaches of Parismina, they are endangered.

Green turtles

are not actually green but take their name from the color of their body fat. The beaches between Parismina and Tortuguero are believed to be the most important Atlantic nesting grounds for these turtles.

Hawksbill turtles

are often for their shells which are the source of tortoiseshell, a translucent brownish-yellow material. It is critically endangered.

Scientific evidence supports the theory that marine turtles return to the beach where they were hatched; some species are known to travel thousand of miles at sea to reach their nesting site.

Places to see nesting sea turtles in Costa Rica

The main places to see nesting sea turtles are: Santa Rosa National Park (near Liberia ), Las Baulas National Marine Park (near Tamarindo), Ostional National Wildlife Refuge (near Playa Nosara), and Tortuguero National Park (on the northern Caribbean coast).

Playa Grande

The beach and the Park Las Baulas are located in Santa Cruz , Guanacaste. Access is by means of the road from Liberia- Guardia- Filadelfia- Belén- Huacas- Mata Palo- Playa Grande.

This National Park protects 445 hectares of beaches, forests and mangrove swamps on the coast of the Nicoya Peninsula in Santa Cruz Canton. It was created to protect endangered wildlife species, especially the leatherback turtle.It is also home of: termites, racoons, caymans, ctenosaurs, pacas, agouties, grey squirrels, howler and white-faced capuchin monkes, 174 species of sea and land birds, etc.

The beach at Playa Grande is where the leatherback turtle comes to lay its eggs. This sea turtle can measure up to 2,5 meters, weigh around 700 kilos and has no hard shell, but rather a black, leathery skin.

It life in the warm, tropical seas, coming ashore only when the females nests. The nesting season for the Giant Leatherback turtle is from October-April at selected sites along Costa Rica 's Pacific Coast and from February-July along the Caribbean Coast . Female turtles mate every 3-4 years, returning to the same beach where they were hatched to lay their eggs.

Sometimes Pacific ridley turtles also arrive to nest as they do at Santa Ana and Corcovado National Park .

Nosara & Playa Ostional

Located near the Nosara River on the Nicoya Peninsula in northwestern Costa Rica , close to the Pacific coastline. The best way to reach Nosara is by flying into the small airport by twin-engine prop plane from San Jose . It's about a 30-minute flight.

The major attraction at Nosara is Playa Ostional . Here Olive-Ridley Sea Turtles come ashore to nest. These turtles nest from July to December.During nesting season some turtles come ashore every night, these occur primarily in peak season of August-September.

Only Olive-Ridley and Kemp's Sea Turtles, the latter an Atlantic species, nest in synchronous waves, and Ostional is the most significant nesting beach for Olive-Ridley Sea Turtles in the world.

Tortuguero National Park

Sea turtles have probably been nesting on the beaches of Costa Rica since time immemorial, but it's only been within the past 30 years or so that research has been publicized about it. This world awareness began when Dr. Archie Carr, the founder of the Caribbean Conservation Corporation, came to Tortuguero in his search for the nesting sites of the green sea turtle.

The work of people like Dr. Archie Carr made the world aware of the potential loss of these beautiful creatures, and protection programs now exist in nearly every corner of the globe.

The small village of Tortuguero lies on the north-eastern Caribbean coast of Costa Rica , approximately 50 miles north of the principal Port of Limon .

The park includes over 19,000 hectares (46,900 acres) and protects 22 miles of nesting beach from the mouth of the Tortuguero River south to Parismina.

Tortuguero is warm and humid. Daily temperatures average 26 degrees C (79 F) and annual average rainfall is over 5,000 mm (200+ inches).

Species diversity of both plants and animals is very high here among the highest in Costa Rica . Abundant wildlife inhabits Tortuguero, including 57 species of amphibians, 111 species of reptiles, and 60 species of mammals. Also more than 300 species of birds live in here.

The black sand beach of Tortuguero draws the largest nesting population of green turtles, Chelonia mydas, in the Atlantic Ocean .

It is important nesting habitat for leatherbacks, Dermochelys coriacea, the only sea turtle without a hard shell. Leatherbacks are killed for their body oil, which is used for fuel and medicinal purposes.

These gentle giants are also vulnerable to marine pollution. Leatherbacks may die after eating floating plastic bags, which they apparently mistake for jellyfish -- their favorite food.

Parismina

At least four types of sea turtle nest on the beaches of Parismina including green, leatherback, hawksbill, and loggerhead sea turtles. The turtle season is longer in Parismina than in neighboring Tortuguero because of the large number of leatherback sea turtles that nest in the black sand dunes of the beaches near Parismina.

The Leatherback Sea Turtles nest from February to July, peaking from mid April to mid May. The Green Turtle's nesting season runs from July to October with the largest numbers arriving in august. The hawksbill turtles nest from march to October.

Commercial fishing, particularly 'long line' fishing used to catch ocean fish such as swordfish and tuna, is believed to be the leading cause of the decline in global sea turtle population.

'Debris ingestion' is another leading cause of death, particularly among leatherback turtles. Turtles mistake plastic bags or other garbage for desirable food items (such as jellyfish- a leatherback staple). Eating plastic leads to intestinal blockage and possible death.

The Parismina Turtle Commission operates along the Caribbean beach of Parismina , Costa Rica . In April of 2001, the Costa Rican Coast Guard and volunteers from Parismina started a turtle hatchery to combat the effects of widespread poaching. During nesting season, they patrol the beaches at night trying to stop the poachers while gathering eggs from the nests and relocating them to the hatchery.

These are some recommendations if you go on excursions to see nesting turtles:

Make sure that you and/or your guide do not disturb the turtles. Any light source (other than red-tinted flashlights) can confuse female turtles and cause them to return to the sea without laying their eggs. Luckily, many of the nesting beaches have been protected as national parks.