A Turtle’s Pace

By Greylyn Owens

Chapel Hill, NC, United States

It is an amazing experience when you step onto the beach of Playa Ostional. For visitors to Costa Rica it is a once-in-a-lifetime event, but for the locals it is something that happens every year. Huge groups of olive ridley sea turtles migrate to the Ostional beach yearly to lay their eggs. They arrive at night between the months of July and December.

There is a Spanish term for the span of time that the sea turtles come upon shore: arribadas (“arrivals”). The arribadas occur every two to three weeks and can last for up to seven days. Tens to hundreds of thousands of turtle mothers lay eggs during that time.


The olive ridley turtles get their name because of their shell color. As hatchlings the shell is gray, but adults sport an olive tint. Mature turtles can weigh up to 100 pounds and grow to 2.5 feet long.

Journey to Motherhood

The female turtles travel miles and miles to lay their eggs under the full moon on the same beach where they were born. So many turtles come ashore to nest that sometimes the first batch of eggs will be destroyed by the subsequent wave of turtles. The females will lay approximately 100 eggs about two to three times a year. Their eggs are not like your normal chicken egg. They are roughly the size of a ping pong ball and have a soft shell.


After 50 to 60 days, the eggs hatch. Baby turtles pop up out of the sand and start making their way to the ocean. They have many obstacles before they even reach the water. Dogs, birds, and people all present dangers.

Once the hatchlings reach the water they face a new set of predators. Due to consumption by fish, crabs, and other sea animals, only a couple of turtles from each batch of eggs survive their journey to freedom in the open ocean.


The olive ridley turtle is an ancient species that is at risk of becoming extinct due to habitat destruction. If you are ever able to be a part of an arribada, don’t let the moment pass you. This is a great example of the circle of life and is an experience you will never forget.

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stilt fisherman in Sri Lanka
Stilt fisherman in Sri Lanka


Math Resources
  1. Do some research to find out how many eggs a turtle will lay in a year.
  2. If 20 percent of hatchlings makes it to the open water from their nest, how many will get there safely?
  3. How big does a nest need to be to hold 100 eggs?
  4. Would it be better for the mother to dig a round or a square nest? Justify your answer.
Extension Questions
  1. Do some research about the human threats sea turtles face when they travel to and from arribadasWhat can we do about these?
  2. How can we help increase the population of sea turtles in our oceans?
Explore Further
  1. Information about sea turtle nesting behavior
  2. Facts about olive ridley sea turtles
  3. Website for the Turtle Rescue Hospital in Florida
  4. Video of an arribada at Playa Ostional
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