One of the most important locations in the world for the survival of Olive Ridley Sea turtles, Ostional Wildlife Refuge in Guanacaste consists of 238 hectares of protected land, including 15 km of beach where thousands of turtles can be seen laying their eggs.
If one of your must-do or must-see things to do for your trip to Costa Rica is to see turtles, then consider putting Ostional Wildlife Refuge on your list as it is one of the best places in the country to see them during certain months.
Read our guide to find out more about visiting this special place in Costa Rica!
Ostional Wildlife Refuge
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- Location and Directions
- Sea Turtle Nesting and Hatching
- Visiting and Volunteering
- Lodging, Town and Beach
Established in 1983 as an official protected area for the sole purpose of protecting the crucial nesting site of the Olive Ridley Sea turtle, the Ostional Wildlife Refuge consists of Playa Nosara, Playa Ostional, and the beach town Ostional.
Since there were many poachers and people stealing eggs for drug trafficking, it became necessary to protect this land and so the government created the refuge. Now thousands of turtles are safe from harm every year with guides and rangers patrolling the beach. Visitors can come to this beach to witness the spectacular nestings of turtles and hatchings of babies.
Location and Directions
The refuge is located in the Nicoya Peninsula, about 50 km from Nicoya city.
Directions by driving: If you are coming from San Jose, take Route 27 towards Puntarenas. Take a left to the Puente de la Amistad de Taiwan and go towards Nicoya. After about 18 miles on this road, head towards Nosara turning right. This will be a bumpy dirty path with many potholes. It is recommended to have a 4×4, especially in rainy season.
Keep following the signs towards Nosara and you will also see signs for Playa Ostional. At one point, you will have to cross Rio Montana. This river can get quite high in rainy season.
Bus: From Santa Cruz, take the bus leaving at noon to Ostional which returns at 5 PM. Another way is to leave from San Jose to Nosara by bus which leaves at 530 AM and from Nosara take a taxi to Ostional.
Safety tip: If you are visiting, make sure you rent a 4×4 and be extremely careful with the river. If you are renting a car, I highly recommend renting a 4×4, especially in rainy season. **Remember that river crossing damage is not covered by insurance as it is considered negligence.** If the river is way too high, you will need to park your car and walk the last 2 kilometers.
Sea Turtle Nesting and Hatching
The majority of the turtles that come to nest are the Olive Ridley sea turtle but leatherback and pacific green turtles can also be seen during certain months. The first documented occurrence was in 1959 and in 1970 began the official research of this phenomenon in Ostional, started by Dr. Douglas Clark.
The turtles come to nest all year long at Playa Ostional except during the time of arribada, which means arrival in Spanish, thousands of Olive Ridley turtles simultaneously come to Ostional to nest during the night.
This arribada occurs in 8 beaches in the world and 2 of them are in the Pacific coast of Costa Rica (Nancite beach in Santa Rosa and Playa Ostional). Ostional Wildlife Refuge is considered as the site of the most reproduction of Olive Ridley turtles in the whole world.
They come to shore to lay their eggs during these few days, which is right before a new moon as they are the darkest. The best time to see this is during rainy season, particularly September to December.
Arribadas occur once a month, sometimes even twice for 3 to 4 days and the largest number of mother turtles during an arribada recorded has been 500,00! The first day of the arribada has turtles coming up to shore from 2 PM until 7 in the morning the next day.
This is the only beach in the world where it is legal for the locals to harvest eggs.
Why harvest eggs?
During the first day of the arribada, scientists have found that the first eggs laid and buried are usually destroyed by the following mothers.
The locals of Ostional and the government developed a plan to work together to collect and harvest the first clutch of eggs and sell them. In return, locals help clean the beach of debris, patrol for poachers and fend off vultures and dogs from newly hatched babies
Each mother lays around 80-100 eggs, first digging out a hole 30 to 40 cm deep and covering it with her back flippers. She camouflages the nest with her front flippers. The whole process takes a couple hours which includes crawling up to shore, digging a hole, laying the eggs, covering the hole and crawling back to sea.
The whole beach of Ostional is littered with white shells. Just the sheer number of shells alone gives you an idea of just how many thousands or millions of baby turtles have hatched and tried to make it to shore.
Baby Sea Turtles
The eggs develop for 45-55 days after the nesting. Humidity and temperature have great influence on their development and their gender. As soon as they’re ready, the baby turtles break out of their shell which takes around 4 hours.
Digging their way out of the nest takes around 4 days and begins with simultaneous movements of all the babies. Baby turtles crawl out of their nest and instinctively head towards the water but wait for the best conditions which can be up to 1 day. They come out from sunset until 11 in the morning and 98% of baby turtles come out at night between 9 PM and 2 AM.
During their first walk of life, they already have to face many dangers: vultures, dogs, crabs, and people. The large number of eggs laid per clutch and the hundred of thousands of clutches laid during arribada increases their chances of survival: it’s all about luck and safety in numbers.
They still need to crawl to develop their lungs and feel the sand so they can remember it if they need to come back and lay their own eggs one day.
Visiting and Volunteering
Things to know if you are visiting/volunteering at Ostional Wildlife Refuge:
- No flash photography.
- If you wish to get pictures, it is best to see the mothers at dawn when the sun is coming up.
- No flashlights or video cameras either. If you take video make sure the blinking light is turned off.
- Wear black clothing when walking on the beach during the night. Turtles swimming to shore will pop up their head to check out the beach and are very sensitive to white light. If they see any sign of white light, they won’t come to shore to nest.
- Please do not touch the turtles.
- Check the Association of Guides in Ostional Facebook page if you want to see an arribada. They post updates on the arribadas when they start and end.
Lodging, Town and Beach
There are a couple conveniently located small hotels in the town of Ostional. The town is very small, with only one soda, a few pulperias and a few cabinas for lodging. The beach is also popular with local surfers.
We were in Ostional for only two nights but we were able to see babies and moms. We worked with a local guide who took us on his daily walk in the morning to take record of how many turtles came and he taught us how to look for nests, freshly hatched babies, and tracks of different turtles.
The turtles that do make it have even more dangers ahead of them in the ocean so it is a gift to see the adults who have survived decades out in the sea, come back to shore to complete their circle of life.
A video of our trip to Ostional Wildlife Refuge
Want to read about more wildlife? Check it out here!
Want to see more turtles? Head to Tortuguero National Park, an excellent place to see Green and Leatherback turtles.
Read about other wildlife reserves in Costa Rica.