At the nesting site on Levere Beach in northern Grenada we were lucky enough to see a nesting turtle on the first beach walk of our turtle patrol. The team are usually out every night starting in mid-Feb until October, with peak nesting season beginning at the start of May. We waited for her to find a place, and begin digging her nest before we moved closer, so as not to disturb her. Once she is digging, as long as you don’t get too close to the front end of her body, she isn’t easily disturbed. We waited for her to be finished and helped a little by removing stubborn vine roots, and quickly refilled in the chamber, due to the growing roots we had to move the eggs for her as they wouldn’t have survived. We caught the eggs as she laid them, putting them into a bucket. We checked her flippers for tags, both microchips and physical metal tags and she had none, with no evidence of a lost tag either, this meant she was a first timer! So we measured her, tagged her and let her go on her way. After she had covered up her egg chamber and made it back into the sea, we took the eggs and found a safer spot for them, higher than the high tide line in a sandy are with no roots. We dug a new egg chamber and counted the eggs into it, recording how many were yolked (fertile) and yolk less (infertile). Usually they lay between 60 and 110 eggs, this girl had laid 101 in total. She had 41 fertile eggs with the rest infertile. It is still unknown why they lay yolk-less eggs, while there are many hypotheses, the reason is still unconfirmed. Leatherbacks lay yolk-less eggs every time, theories for this include: 1. They are excess egg making tissue that she needs to get rid of; 2. They are laid on top of the yolked eggs to protect them from predation; 3. They help to keep the airflow in the egg chamber relatively even. Other species don’t lay yolk-less eggs every time, so the favoured theory is number 1.
Unfortunately for sea turtles, climate change is having very severe and profound effects. The temperature of the surroundings determines whether the hatchlings are male or female. For leatherbacks males are born when the temperature in between 27-29C, females are between 29-31C and above that the eggs are cooked and no babies hatch.
Watching this relatively small female heave her huge body back towards the sea really hits home how vulnerable to predation they are. The way they lay the eggs too, they are easy for poachers to take. Then add in the extra confusion from lights on land, its easy to see why they get stuck on land, this girl had to do a few circles on the beach before she made it safely back into the sea.
