The Turtles

Image: some of the reserva's baby sea turtles (different year)

Here at the reserva, the staff collect sea turtle eggs from the beach and keep them in a hatchery. The hatchery is essentially a greenhouse made of mesh material with sand on the bottom, where the turtle eggs can be buried. Every two hours of every day, groups of volunteers are sent to check on the sand above the turtle eggs to track any changes. They are supposed to hatch this week, so hopefully we will get to see some baby turtles before we leave. I have been sent a few times for the hatchery checks, but as of right now, there have not been any changes in the sand.

There are seven different species of sea turtle in the world, and Costa Rica has four of them. The hatchery at the reserva is currently holding eggs of the Olive Ridley sea turtle, which is the smallest of the four species in Costa Rica. It is also the most common species we find here on this beach. 

Why does the reserva take the eggs and put it in a hatchery? Why not just let the eggs hatch on their own in the wild? They do this for a few reasons. 

Firstly, there are many poachers who dig up sea turtle nests to use the eggs for their own consumption or to sell. We were shown some statistics, and it showed that there were 41 poached nests out of some 200 total nests on our beach in 2023. That year, the reserva was able to save 44 nests.

This picture was also taken at the reserva

Another reason that the reserva takes the eggs is to prevent the eggs being eaten from predators. This includes Jaguars, armadillos, crabs, ants, and humans. The hatchery is locked and surrounded by fences in order to keep out predators and poachers.

The final reason, and the most interesting in my opinion, is to breed more males. If the temperature becomes too cold, the baby sea turtles will be mostly males. If it gets too hot, there will be more females. As we all know, the temperature of the earth has been rising slowly, which means that there are more female sea turtles coming out. To keep the balance between male and female turtles, the hatchery is placed in a shaded area to prevent the sand from getting too hot. 

I looked this up on Google, and it said that if the eggs are incubated below 28C, all turtles hatching will be male, and if incubated above 31C, all turtles will be female. Very interesting.

This is another picture taken by the reserva. If we spot a sea turtle laying eggs at the beach, we will take measurements and check if the sea turtle is tagged. A fun fact is that a sea turtle will always return to the coastline it hatched on. Because of this, many tagged turtles return to this beach every year.

Written by Stephen J