Mid-January marks the start of laying season for Galapagos green turtles (Chelonia mydas agassisi), a subspecies of green turtle that nests nowhere else in the world. In order to protect and monitor this endangered marine reptile, staff from the Galapagos National Park (GNP) have set up camp close to the principle nesting site of the turtles: Quinta Playa on Isabela island.
Looking like soldiers on a night exercise, the staff dress all in black and are equipped with special red lights so as to not disturb the turtles. After splitting into teams, monitoring begins at around 9pm, several hours after nightfall, and continues through until dawn the next day. The staff track down the female turtles making their way up the beach and silently follow them to their nesting sites.
When nesting, green turtles dig out deep pits in the sand before laying an average of 70 leathery shelled eggs which will almost fill the chamber. Once her clutch is complete, the female will scoop sand with her rear flippers to cover the nest, then head back down the beach and return to the sea.
Nest and turtle data are logged by team members and later transferred to the GNP database for reference. After around 50 days the eggs begin to hatch and hatchling turtles will start to emerge. The teams then return to the nests to dig up the remaining shells in order to record how many of the turtles successfully hatched. Eduardo Espinoza, Technical Director of Ecosystems for the GNP, cites that historically, the hatch rate averages around 60%, although this is heavily influenced by seasonal and environmental conditions.
Incredibly, only one in every thousand hatchlings will survive to adulthood, as predation rate is very high. On their perilous journey from nest to sea, hatchlings are picked off by birds and crabs, and once waterborne they face an array of marine predators. Even as adults they remain vulnerable to sharks and other large marine species. The park staff also carry out activities related to the control of invasive predators such as rats and feral cats, which destroy nests to get to the eggs and eat the soft-shelled hatchlings.
In addition to these measures, the GNP are working with the Charles Darwin Foundation to determine the frequency of boat-turtle collisions in the area. During this time of year, large pregnant females spend much of their time close to the surface, increasing their vulnerability to propellers. The aim is to identify areas where boat strikes are more common in order to implement speed restrictions and other regulations to users of the Marine Reserve.
Observing hatchling turtles emerging from their nest is an incredible experience wherever you are in the world, but there are a few things to bare in mind. If you’re lucky enough to have this opportunity, please remember the following simple guidelines:
- Avoid using torches and flash photography. Turtle hatchlings navigate using the stars and the moon so can get very disorientated if there are unnatural lights around them.
- Don’t block their route to the sea. You should stand well back from the nest and give the hatchlings plenty of room to make their way down to the water.
- Don’t pick them up. Whilst it may look like they’re struggling at times, they are persistent little critters that have evolved to overcome obstacles on the beach such as rocks and driftwood, so avoid the temptation to help them on their way.
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The content of this post was translated and adapted by Isabel Banks from a Press Release sent by the Galapagos National Park.