Nesting and hatching in Marino Las Baulas National Park, by Shona
05.03.2015 - 10.03.2015 35 °C
The beach at Playa Grande, which lies within the Marino Las Baulas National Park, provided an awesome opportunity for our family to hone their surfing, boogie-boarding and castle-building skills (or lack of skills!) during the day. But shortly after sundown each night the beach was closed and the true beauty of the national park designation revealed itself. Las Baulas National Park is the prime nesting site on the Pacific coast, and one of only a few remaining nesting sites in the world, for the massive Leatherback turtles. Slightly less endangered and somewhat smaller Olive Ridleys and Blacks (confusingly sometimes called Greens) also make their nests in this park.
When planning our visit to Playa Grande we thought we would catch the end of the Leatherback nesting season which is supposed to go until the end of March, but we were a bit dismayed to find out on our arrival that fewer Leatherbacks had come this year, and those that had nested had moved on a month or so earlier than usual. We were pretty disappointed, but were too lamely focused on our own bad luck to consider the poor turtles!
We regrouped and figured that if we were smart with our time and were very lucky we might get a chance to see one of the other types of turtles nesting and possibly see the hatching of some baby turtles. We all frantically crossed our fingers and signed up for a night-time turtle tour. These tours are run by guides who formerly harvested the turtle eggs and sold them to restaurants. Their nest hunting skills are now put to better use and the newfound tourism revenue has encouraged the locals to support turtle conservation efforts. A 30 minute bumpy jeep ride delivered us to another beach where there were reported nestings happening that night by Black turtles. We were not allowed lights of any kind (hence the lack of photos) and we had to stay very quiet while waiting and watching.
As nightfall arrived a mother turtle painstakingly hauled her gigantic body up the beach until she found a suitable spot to begin building her nest, and we left her in peace to do so. We would check on her after she was done digging the nest and was ready to lay her eggs. Once our eyes adjusted to the moonlit darkness we noticed a few sets of tracks coming from the water's edge. (These resemble the tracks from a very large tractor tire) so we knew there were a few other mothers laying at that moment. We waited on the sand for about an hour and despite their excitement the kids did a great job in staying silent and waiting to launch their hundred questions until we were safely away from the quiet of the beach and headed home. Instead we silently laid on our backs and gazed up at an unbelievable night sky so full of stars that it filled us with awe. During this time several other turtles had stealthily crept up from the beach to nest or had headed back to the ocean after laying their eggs. Two cute little coatis, which are similar to raccoons, ran along the beach.
Once a suitable spot was found, it took a mother turtle about an hour to use her back flippers to dig a hole close to one metre deep to lay about 100 eggs. The guides told us that there are usually 30 billiard-ball-sized fertilized eggs and the remaining eggs are ping-pong-sized, un-fertilized eggs. On the night of our tour things seemed to suddenly go haywire. The silence was broken by many Walkie-talkies going off and guides running around with their red, night-vision flashlights. Apparently those cute looking coatis we had spotted earlier had raided one of the newly laid nests!
The entire nesting process, though fascinating, looked entirely EXHAUSTING. But wait, there's more... These mothers nest every 15 DAYS throughout the 3-4 month-long nesting season and THEN swim all the way to the Galapogos Islands for a well deserved break. And IF they are able to avoid danger while out at sea (many die each year in fishing nets or from oil pollution!) they will return to the same beach (if there hasn't been too much beach development!) in a year or two to do it all again! Until they are 80. Years. Old. Good grief.... the nesting was amazing to witness but I silently but very sincerely thanked Mother Nature that I'm not a female sea turtle!
Several weeks after the eggs are laid the baby turtles are ready to hatch under the cover of darkness. The beach at Playa Grande reopens each morning at 5am so we tried our best to adjust our sleep schedule so that we were waking up very early each morning in an attempt to witness the final moments of a hatching. On most mornings we had the entire beach to ourselves except for a few other turtle loving tourists and a researcher from the marine biology station who would scan the beach for evidence of nestings or hatchings. Here's Mirren posing one morning beside some tracks left by a mother turtle the night before.
One researcher we met was very informative. She was trailed by several American high school students who were visiting and shadowing her research for a week, (our kids: "OMG! I'm totally doing that when I'm their age!"). We learned from her that the temperature of the sand strongly influences the gender of the baby turtles. If it is higher than 29.5 degrees Celsius the turtles that hatch will more likely be female. Male turtles are more likely to hatch when the sand temperature is lower than 29.5 degrees. It was definitely on the higher side at Playa Grande so any newly hatched turtles would very likely be female.
One morning we noticed several Olive Ridley baby turtles (about the size of the previously mentioned billiard ball) trying to crawl out of a hole in the sand and make their way to the ocean. They were a little late to the party... The tide was quickly receding so that their journey to the edge of the ocean was now much longer than that faced by their siblings who hatched several hours earlier. To our kids' distress, two baby turtles were already dead in the nest by the time we arrived, either from exhaustion or overheating. The biologist gave us the job of trying to scare away the circling birds while the live babies tried to crawl to the ocean. The kids got to name one of the Olive Ridley baby turtles and chose 'Oliver' in honour of their cousin! Here is a short video of two turtles reaching the ocean and facing the surf.
The following morning as we walked along the beach at dawn we noticed several sets of miniature tracks heading to the ocean from another hole in the sand. There was one baby Leatherback turtle still making her way to the ocean! The kids immediately stood guard and chased the birds away. Norm captured this turtle's attempt at the epic journey from nest to sea. His sincere apologies go out to our family's film students, Teagan and Tyrell, as his camera work is more than a bit dodgy (especially at the end when he completely turns the iPad).
Our biologist friend came back and this time took the baby Leatherback back to the research station with plans to release her that night under the cover of darkness, to avoid the daytime birds and improve this Leatherback's chance of survival. During hatching and crawling to the ocean the texture and composition of the sand and the beach location gets imprinted into a turtle's brain and she will only return to the same exact location to nest in 25 years time when she reaches sexual maturity. The Leatherback turtles are too endangered for the researchers to sit back and watch as nature unfolds. Only one in one hundred Leatherback eggs produce a turtle that will reach adulthood! The biologist checked the nest and the tag told us that the nest was laid exactly eight weeks earlier. She let the kids name the baby Leatherback and this time they chose Negra Bella, Black Beauty, which was a very suitable name. She was positively stunning and we felt so grateful to have had a very minor hand in her start in the world.
Would she be one of the lucky ones to survive? Again, we all frantically crossed our fingers. Except this time it was not for our own chance to witness something as amazing as a sea turtle nesting or hatching, instead we were all desperately hoping that these majestic creatures who have existed for millions of years will find a way to survive in an ever changing world.