For the past few weeks we have been walking the beach in search of sea turtle activities. Yes, they are back.
This year, we have had over 30 leatherback activities on the beach where we do day patrols. An “activity” may be just a track left by a turtle coming up on the beach during the night to look for a nesting area, or it may be an attempted nesting, or an actual laying of eggs.
Sometimes when a female makes her way onto the beach, she is frightened away by something before she has a chance to even begin the process of moving sand. Sometimes she actually finds a place that seems appropriate but the sand caves in or she hits tree roots and hasto start over again. It’s a tedious process, fraught with challengers, danger and uncertainty, but we are fortunate that they are determined to get the job of passing on their DNA to future generations done.
We have a special permit to work with the endangered species, the Leatherback turtle, the Green turtle and the Hawksbill turtle.
So far this year we have excavated six or seven leatherback nests and one hawksbill nest.
This is how it works. For months, beginning in April or May, volunteers walk along a beach in the mornings. When we notice a track in the sand made by a sea turtle, we decide whether the track led to a successful nesting activity, which we call a “probable lay”. If we think the turtle was able to complete the nesting process, we determine where we think the nest is in the sand. This takes some practice because we don’t dig into the sand at this point. We have a gps, which we place on the approximate spot, and we use a long metric measuring tape to triangulate the point between two numbered stakes near the vegetation line on the beach. We record the gps coordinates, the distance between two stakes, the vegetation line and the high water mark, and any other interesting observations, such as whether the nest is likely to be washed away because it’s too close to the water, or if there is a risk of predation by mongoose in the area, or if it might be affected by light pollution from nearby houses or hotels…..We also leave a numbered tag on a tree or bush behind the nest are to help us remember where the nest is when it comes time for the eggs to hatch.
We walk the entire beach checking for these activities. Some tracks left in the sand do not lead to actual nests, as I’ve mentioned above. We call other types of activities either a “dry run” where a nest may have attempted but was interrupted, or a “track only”, where the turtle just came up onto the beach and left without doing anything.
Between 45 and 60 days later, we look in the sand in the marked areas for tiny turtle hatchling tracks coming from a depression in the sand. Sometimes the tracks are obliterated by rain or wind, and we just find a depression in the sand. Sometimes we find a disoriented hatchling or one that was caught by a bird and dropped. Any of these things tell us that a nest has probably recently hatched and we need to dig somewhere in the vicinity.
We look back at our recorded data and start digging where we think the nest is. Michael is the digger and I record the findings on another data sheet. Sometimes we find live hatchlings which we release into the water at an appropriate time, and sometimes we just find hatched shells and under developed eggs which never hatched. The number of hatched shells we count tells us how many baby turtles made it out of the nest, and hopefully into the sea.
The leatherback nests we’ve excavated this year have had between 30 and 55 hatched shells in each, and the hawksbill had 92.
Check out the great pictures on this website if you haven’t already clicked on the last link above. Michael and I saw our first actual turtle nest hatch when we were on our honeymoon trip in Lauderdale-by-the-Sea, in Broward County, Florida, where many of these pictures were taken.
