Turtle Arribadas at Ostional Costa Rica

fig3 Turtles arriving in late afternoon, courtesy Rolf Lichtenstein

fig1 Turtles coming and going at first light

The Arribada of Olive Ridley turtles in Costa Rica is one of nature’s great events and is an amazing spectacle to experience.
The mass migration occurs during the wet season from May through November starting  approximately seven days before each new moon on the black sand beaches at Ostional, a small seaside village located on the Pacific coast of Costa Rica.
The first wave begins with a few hundred turtles coming onshore, with the numbers increasing rapidly over the next few days to a peak that can exceed 20,000 turtles per night. The numbers then progressively fall to zero before the new moon.
Some of the locals believe that the 60cm uplift of the seashore by the large 7.6 magnitude earthquake of 2012, has changed the timing of the Arribadas. They now appear to start later in the night following high tide and last longer till dawn. However, nature is unpredictable and during a very large Arribada the turtles can start coming onshore during the late afternoon as shown in Fig3. Note that few onlookers are present as this happening was unexpected.

Access to Ostional Beach

fig5 wading creek to access southern part Ostional beach

fig4 Ostional beach looking north at central access

The beach is open freely to visitors up to the time when the authorities declare a formal Arribada, determined by the arrival of a significant number of turtles. It is then expected that visitors will hire official guides at $US10 per person/per visit for an official wildlife guide and $US8 per person/per visit for a local guide. The guide can be booked in advance from the  Ostional Wildlife National Refuge office¹: (506) 2682-0400 or the Ostional Local Guides Association office¹ : (506) 2682-0430. Both offices are located either side of the main street in the centre of the village.
English can be understood by some officials in the offices.

Once the Arribada is announced, both offices are open all day, and from dusk to dawn when the turtles are on the beach. The beach is freely open to visitors from 7am to dusk, or when there are no turtles on the beach. Most visitors hire guides for a night tour, with 7pm being a popular start time, but by then the sky is very dark and visibility is restricted using the allowed red coloured torches. A good time for photographing the grand spectacle, is to arrive at the centre of the Arribada some 45 min before dawn, when the sky starts to lighten, and one can still see large concentration of turtles and witness their return flight to the sea (fig1). At this time, some late turtles are still arriving.
Dawn is around 5:30am with first light occurring some 40 -30 minutes earlier. If the Arribada is in the central part of the beach, allow for a 20 minute walk from the guide office to get into place. This requires leaving the office with the guide around 4:30-4:40am. This time will have to be adjusted to get to the correct position just before first light if the dawn is at a different time or if the Arribada is further along the beach.

fig7 one of the last turtles

fig6 vultures hassle the turtles to get to eggs

Note:
♦ The Arribada can occur along any section of the beach that extends some 2km north and south of the main village beach access ( see fig13). However, once established all further happenings will occur in the same location.
♦ No flash photography or white light torches are allowed. The guide will have a red light torch, and some hotels can provide red plastic to cover your own torch.
♦ Arribadas occur during the darkest nights.
♦ Staying within the rules visitors can get close to the turtles.
♦ For photographing, the turtles, it is best to go to the beach in the light of the pre-dawn when the last turtles dig their nest.

Ostional Turtle Eggs Harvesting

fig9 collecting the turtle eggs of the first wave Arribada

fig8 harvesting turtle eggs

Once the Arribada is established, the subsequent waves of turtles will occur at the same area, with each wave excavating the eggs of the former.
To prevent indiscriminate loss of these eggs, the authorities have allowed the local people to harvest commercially a proportion the eggs of the first wave. In return, the locals keep the beach clean of debris that would inhibit the migration, and protect the hatchlings in their flight to the sea from the vultures which otherwise would kill all the newborn turtles.

How to get to Ostional

i) By road

Ostional is about a five hour drive from San Jose via the new highway through Orotina and Caldera on route 27.

fig12 Road to Nosara blocked by swollen river

fig11 fording stream outside Ostional

fig10 Route map San Jose to Ostional; google earth; Wikimaps

From Caldera follow the international highway No.1 until the turn off for Nicoya at Tempisque Bridge at Puente La Amistad. From Nicoya, there are two possibilities, but the shorter southern route via Nosara is not passable during the wet season as two rivers need to be forded. The northern route goes through Santa Cruz Playa Lagarto, Marbella.
It is essential to have a 4 wheel drive as the last 30 km are gravel and the last 5km can get badly potholed between road gradings, and a small stream must be forded some 3k before Ostional.

fig13 Ostional accommodation and feature map; Google-earth

Note. Santa Cruz is the last place for petrol and is a good one and a half hours from Ostional, so it is advisable to fill up the tank here. Gas stations take Amex and Visa, but not mastercard  credit cards and both US dollars and local currency. Also, it is advisable to rent a GPS, as the road signs are not always present. The GPS also gives warnings of danger, speed traps, and other services. After Santa Cruz the speed limit varies from 60km/hr to 80 km/hr with frequent school zones of 25km/hr. Many of the locals ignored the speed limit, with many vehicles not slowing for the school zones. I saw one semi-trailer on its side going to Ostional and one on its side coming back. I also saw a number of police cars patrolling the region.

ii) By plane

Fly Nature air or Sansa Air to Liberia airport, thence a 2 hour drive on route 21 to Santa Cruz.  Then by road as above.
Fly to Nosara by Nature air and get the hotel to pickup you up. Available only during the dry season.

iii) By Bus

The San Jose-Santa Cruz bus service is operated by EmpresaAlfaro.com.
The Ostional bus departs from Santa Cruz main bus stop. The schedule changes, but  the bus normally leaves Santa Cruz at 12:00 noon arriving into Ostional at 3:00 pm. The  Santa Cruz bus leaves Ostional at 7:00 am arriving at Santa Cruz around 10:00 am.

Ostional Accommodation

fig16 Ostional cabins

fig15 Ostional turtle lodge

fig14 rooms hotel Luna Azul

There are cabins inside the village (e.g. see Fig16) and  few lodges/hotels scattered in the surrounding area within 5km, (e.g.Figs14 & 15).
Cabins: include, Guacamayas¹ (tel: 2682-0430) and Ostional cabins¹ (tel: 2682-0428)
Lodges/Hotels/B&B:
Albergue Arribadas and Turtle lodge  in town, Brovilla Resort Hotel (3.0km), Hotel Luna Azul (4.2Km) Turtle house B&B ( 5.0 km), Fig13.
The upscale small resort hotel Luna Azul at 4.2 km takes 10-15min driving in the dark to reach Ostional. This involves fording a small river (Figs 11 & 13).
Note:
♦ The wet season is the low tourist season for this region with some hotels and restaurants closed.
♦ The peak of the wet season is around October.

¹ From Ostional Wildlife National Refuge