I thought watching the Ridley turtle laying here eggs yesterday was an amazing thing to see. That was only a precursor of what the night was to bring.
I was assigned to the night watch consisting of three groups, each with a biologist and two volunteers. Each team was assigned a section of the beach to patrol from 8:30pm until 2:30am, the time about half way to high tide to half way to low tide.
All the work with leatherbacks is done at night as they are extremely white light sensitive. The turtles navigate by light and when ready to lay their eggs they head for the darkness of the beach.
They return to the sea using the light of the moon, stars and surf. In fact, we are not allowed to use flashlights. When working directly with the turtles, always from the back, we use head lamps covered with red cellophane. All the homes along the beach have red out side lights.
Since the tide was coming in most of the time we were walking, we had to walk in the soft sand covering about 8-10 miles during the night. (I have 3 blisters on my feet to prove it.)
The first part of the night we saw one black turtle come out of the water, travel about half way up to the soft sand, then turn around and head back to sea. That was a huge disappointment as this was about all that was going on in our portion of the patrol.
The other two groups each had a leatherback make it up to the soft sand, partially dig a hole to lay her eggs, then change her mind and head back to the sea. I guess this is fairly common, but they will all return in a day or two to accomplish the laying of their eggs.
Each turtle returns to the beach about every 4-5 days to lay eggs, usually around 50 to over a 100 eggs each time, and will return about 7-10 times during a season.
It was getting on to around 1:30am and we were pretty discouraged by this point thinking that was all the action we would see. It was about that time that the action started. In the final count, our team had two successful leatherbacks and the other two teams each had one successful leatherback for a total of four.
"My" turtle was around 600 pounds and over 5 feet long, about average for a leatherback, although the males can get as big as 1000 pounds. I got to lay in the sand behind her as she dug with her rear flippers down to about 3 feet. When she began dropping her eggs into the hole, I had to hold one of her flippers so I could count her eggs. This is way close and personal and quite frankly it took me back to the days I worked in Labor and Delivery.
The eggs are about the size of a billiard cue ball, white and very shiny from their soft shells protected by clear mucus. There was a definite musky smell, not unpleasant but unique. While actually laying her eggs, the turtle goes into a trance and becomes completely unaware of her surroundings. Out of respect for the turtle, no one is allowed to go in front of her at any time, even when she is in this trance.
While the eggs are being layed the researcher and volunteer take measurements. If she had not been tagged, a microchip is inserted near the arm pit of each front flipper. This one had been tagged previously and the chips were scanned to ID her.
Once she has completed her eggs she begins the task of covering the nest with sand using her giant rear flippers. First one flipper digs up the excavate pile of sand then pats it down gently, then the other giant flipper reaches out to the side, picks up some sand, puts it on the nest and pat pat pat. She sticks her tail into the sand to determine how firm she is patting the sand down over her newly laid eggs.
Once this is complete she will turn a circle in the sand over the newly covered nest site, crawl slowly to another area and turn another circle to create a fake nest site before she heads slowly back to the ocean.
She will return again and again this season to lay more eggs, her noble attempt at saving her species. Out of 1000 eggs hatched, only one will survive to adulthood.
I am in awe of the process of nature even more so after watching these giant turtles work so hard as they have done over the past thousands of years.
Until the 1990s there were as many as 100 leatherback turtles laying eggs on this beach each night. With the encroachment of houses, people and poaching, we are now down to about 35 turtles per season.
Poaching was stopped, red lights were used near the beach in the late 1990, and the beach became a protected area during the nest season. The numbers have turned upward over the past 3 years. With the determination of the species to survive, and the dedication of scientists and the population of Costa Rica, there is hope.
So what is a little lack of sleep, blisters on my feet and sore legs now that I have been a part of this life cycle process? I am pumped!