It is a scene that has been shown countless times in nature documentaries over the years, but it is one that always sticks in the memory. Hundreds if not thousands of tiny baby turtles making a break for freedom across the beach, aiming to begin their young lives in the world’s oceans. This is a site which those who have been fortunate enough to see it live have called “breath-taking.”
Now, whilst everybody knows what happens as the tiny-limbed turtles crawl across the sands, very few are aware of how they get to that stage or what happens after they make it into the wash. We wanted to take a closer look at the hatching process of these amazing animals, and to help volunteers get a better idea of just what a large role they play in the protection of these animals on our turtle conservation projects.
Stage 1 – Incubation
After the female turtle has safely buried her eggs under the sand, they will have to spend time incubating. Incubation times vary from species to species, but they always depend on a combination of clutch size, temperature, and humidity in the nest. The incubation time for most species is within the 45-70 day range, so the turtles need to ensure that they remain safely below the sand for this duration.
Research has indicated that the sex of each embryo is determined sometime after fertilization, and it thought that lower nest temperatures will produce more males, and higher nest temperatures will produce more females! This is a strange but true piece of information.
Stage 2 – Hatching
Sea turtles hatch throughout the year, but the biggest period for hatchlings is the summer. The baby turtles will use a carbuncle, or temporary egg tooth, to help break open the shell and begin their journey to adulthood.
After they have hatched, young turtles can take anywhere between 3 and 7 days to dig their way to the surface. It all depends on their numbers and how deeply mum decided to bury them! When they reach the surface, the hatchlings will normally wait until the cover of nightfall to make a break for it, as this will help them to avoid the predators that lurk outside hatchling sites in the daytime. Baby turtles more often than not adopt the tactic of safety in numbers, and will all head to the sea at the same time.
Stage 3 – Reaching the Ocean
How on Earth do these new-born turtles know how to reach the ocean in the pitch black surroundings of a vast beach I hear you ask. Well, there are two theories as to how they manage this feat. The first is that the turtles are able to distinguish between differing light densities and they then head for the greater light intensity of the open horizon. The second theory is that during their crawl to the sea, the hatchlings could set off an internal electromagnetic compass which they use to navigate away from the beach.
Whichever method they use to reach the ocean, once they have located it the hatchlings dive into a wave and ride the undertow out to sea. As soon as they reach open water, a “swimming frenzy” takes place where the hatchlings swim for 24-48 hours to ensure they get into deeper waters where they are less vulnerable to predators. There have been reports of turtles diving when birds or even planes fly overhead, and this is thought to be an evolutionary reaction to help avoid predators.
Stage 4 – The First Year
Very little is known about what happens to baby turtles in the first year of their lives as they are very rarely seen. This has become known as the “lost year.” Researchers generally agree that most hatchlings spend their first few years getting to grips with the ways of the ocean by drifting on the prevailing sea currents, living between floating seaweed where they can easily find food. It is thought that turtles spend the first few years of their lives living like this before migratory patterns and instinct kick in and they make their way back to coastal areas.
Turtles have a very tough start to life when compared to many other animals, as they are on their own from the outset and have to avoid a plethora of predators before they even get to face the challenges of the open sea. Humans are another big threat to the turtles, and poaching of sea turtle eggs is something that is rife in countries all around the world. This needs to stop, and turtle conservation volunteers play a big role in this.
