Sea turtles are an ancient lineage of reptiles whose ancestors arose 110 million years ago. While these primitive turtles are now extinct, their relatives still roam the oceans to this day. Of the seven species of turtles, I have had the privilege of seeing five of them, the Green, Loggerhead, Hawksbill, Leatherback, and Kemp’s Ridley. Each of these species has different habitats, diets, behavior, and lifespans.
For example, Green sea turtles eat vegetation, Leatherbacks consume jellyfish, and Hawksbills forage on sponges. However, one thing in common is that all these species will come ashore to lay eggs. Interestingly, all these species nest similarly in a six-step process.
Emerging
During this time, the turtle first crawls out of the ocean and pulls itself up the beach with its flippers. It is important to remember that sea turtles spend the vast majority of their time in the water. As such, they are not adapted for life on land and may appear slow and clumsy. How would you like pulling yourself up the beach with flippers!
While emerging turtles are looking for a good spot to lay eggs. Ideally, this will be above the high tide line in an area clear of debris. Curious humans or wildlife that gets too close could easily frighten an emerging turtle. This results in the turtle turning around and heading back to the ocean in an event often called a false crawl.
Body Pitting
Once the nesting mother has found a suitable area, she will start to dig a body pit. As its name suggests, this is literally a pit that the turtle will dig until it is inside a depression in the sand. Surprisingly this step can take quite a while and well over an hour in some species. What is the function of a body pit you might ask? It clears the area of debris like shells, vegetation, and driftwood while making it easier to dig an egg chamber.
Egg Chamber Excavation
After that body pit is completed to the turtle’s liking, it is time to make the hole where the eggs will be laid. Sea turtles will use their rear flippers to dig a deep chamber in the sand. In Leatherback sea turtles, this chamber can be deeper than 3 feet while in other species it is usually 1-2 feet. Once completed, this chamber will serve as a bulb-shaped air pocket under the sand that holds all the eggs.
Oviposition – Egg laying
Once a sea turtle has started laying eggs, it has entered into a sort of “trance”. That means that the turtle is unlikely to be disturbed at this point. She will continue the process to ensure all the eggs are safely deposited. While laying, eggs are dropped from the cloaca down into the chamber usually singularly or in pairs. This process can be quite exhausting for the turtle as there are around 50 to 150 eggs on average depending on species.
Covering and Disguising
Immediately after laying the final egg, the turtle will use her back flippers to push sand over the exposed egg chamber. These flippers will then be used to smooth the sand and pat down the area ensuring it is compact. The turtle will then throw and push sand backwards with its front flippers to pile sand on top of the nest. This step ensures the nest is protected and difficult for predators to locate. However, this also means that even turtle researchers can struggle to find where those eggs are hiding.
Returning to Sea
After the long and strenuous nest laying process, sea turtles will move out of the nesting area and begin the crawl back to the sea. This action will take longer than emerging since turtles will typically stop and take breaks.
They can often be heard huffing and puffing during this time as they endure this last crawl to the sea. Imagine spending your whole life in the sea and then coming ashore for a few hours to nest. Upon reaching the sea, the turtle disappears into the waves returning to its natural environment once again.
Below is a video of the entire nesting process:
