Baby turtles wait in the nest for their siblings so they can all head out to sea together

TurtleSense can detect synchronized bursts of sea turtle movement during hatching followed by periods of cessation, as confirmed by infrared video footage recorded within the nest.
Credit: Clabough et al. 2022, PLOS ONE; Jo Young at Renegade Pictures (CC-BY 4.0 https://creativecommons.org/licenses/by/4.0/)

Sea turtle populations around the world are under threat. Conservation efforts focus on protecting and guiding hatchlings as they spill out from the nest, but the current method to predict when the eggs will hatch – which typically involves counting the days since the eggs were laid – is inaccurate, labour-intensive and not cost-effective.

Enter: TurtleSense.

This miniature, low-cost sensor resembles a sea turtle egg and is designed to monitor the movement of hatchlings from within the nest, allowing scientists to monitor the eggs remotely. Data captured from research on loggerhead sea turtle nests on Cape Hatteras National Seashore in North Carolina in the US, has enabled researchers to predict the emergence of hatchlings almost to the day.

By monitoring loggerhead nests with TurtleSense, scientists detected that the hatchlings in the nest followed a pattern before they hatched: they would move intensely, then be still for some time.

“As each turtle emerges from its shell, it climbs up to join its siblings at the top of the clutch of eggs, creating a wave of commotion among all the other baby turtles in the nest,” says Samuel Wantman, one of the study’s lead author and retired software designer with Nerds Without Borders. “When there is no more commotion there is a period of quiet, which may be the impetus for all the hatchlings to boil out of the nest together.”

Understanding this pattern – which has also been observed in Olive Ridley and Green Turtle nests – is crucial to being able to predict when the turtles were likely to dig out of the nest as a group. It allows conservationists to better predict when to mobilise to protect the hatchlings – which sometimes become confused and head towards bright city lights instead of the sea. It is also an effective tool to identify nonviable, or infertile, nests, all of which reduce the labour and financial costs of conservation.

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Read more: Sea turtle eggs aren’t always what they seem

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“It’s absolutely magical to witness baby turtles poke their heads out of the sand and sprint towards the ocean, but it’s an event that can be very hard to predict,” says Associate Professor Erin Clabough from the University of Virginia in the US, and the other lead author of the study.

“The TurtleSense system is a low-cost, creative solution that remotely allows us to detect how baby turtles synchronize developmental movement within the nest in real time. We can use the system to detect hatching and to better predict when the hatchlings will emerge onto the beach.”

As beaches are often closed to protect threatened and endangered turtle nests, the sensors could also shorten the effect on public access. Turtle-based ecotourism activities could arise around hatching events, benefitting both the local community and the sea turtles.