Olive Ridleys make their home at the Tortugario el Banco
Olive ridley sea turtles (Lepidochelys olivacea) are the smallest of the seven species of sea turtles, reaching a length of about 60 centimetres. They are found throughout the worlds tropical waters.
Olive ridleys are considered to be one of the most numerous sea turtle species, and are famous for congregating in huge numbers to nest. These mass nesting events are known as “arribadas.” As many as 50,000 females can gather in a single night on the same beach to lay their eggs.
However, not all olive ridleys nest in arribadas. Many females choose to nest on their own and there are many “individual” beaches throughout the tropics. The Pacific coast of Guatemala is one of these beaches.
Many times over the last few years I have witnessed the spectacle of thousands of baby olive ridley turtles making their urgent way to the ocean for the first time at the Tortugario El Banco. It is a true wonder of nature.
This year I was privileged to watch a female olive ridley crawl her way up the beach to lay her eggs.
It was 11pm on the night of a full moon at the beginning of December, the sky was clear. It was a beautiful setting. The turtle was still wet when we found her, having just emerged from the Pacific Ocean.
We watched as she found a suitable place, above the high tide line, to dig her nest. Her first step was to remove the top layer of sand. It is hot on the beach during the day and that top layer of sand becomes very dry. Having completed that task she used the weight of her body to create a body pit by moving herself from side to side.
Then it was time for her to start digging the nest chamber. This is a delicate and elegant process, and quite remarkable for a seemingly clumsy creature when out of water. Using her right hind flipper, she supported her weight while her left flipper gently scooped out some sand. Then she swapped and supported herself with her left flipper, this time scooping more sand out with her right.
This alternating process continued for about 15 minutes until to our surprise she abandoned her nest and moved further up the beach and dug two more shallow test burrows, before settling on a spot about half a metre away from the trunk of a palm tree.
She went through the same process as in the first abandoned nest, but this time she laid her eggs, success! Once she had finished, she filled the hole with sand and patted it down by raising her body up and letting it fall on the sand. Having satisfied herself she then scuffed the sand up with her flippers to disguise the location of her nest, before making her way back into the surf. This whole process, from when we first found her, took about an hour and a half.
Once the turtle was safely back in the ocean we inspected the first three nests. When we looked in the first one, the sand at the level of the nest chamber was still dry. If she had laid her eggs here they would have dried up and the clutch would have been lost.
The second and third tests were full of roots that she could not dig through. The fourth clearly met with this beautiful creatures approval. Inspection of the nest revealed 120 eggs.
Although olive ridleys are the most common sea turtle, they are still considered to vulnerable to extinction, with a declining population, by the IUCN. One of the main threats to turtle eggs here, and the one that was most likely the cause of dangerous declines in sea turtle numbers, is harvesting of turtle eggs for human consumption. People now collect the eggs and sell them to turtle hatcheries, called tortugarios, so the eggs can be incubated instead of eaten.
We called our friends at Tortugario El Banco who came and carefully collected the eggs. We took them back to the tortugario where they were reburied. When the babies hatch in around 55 days they will be released into the Pacific Ocean. And so the cycle will begin again!