Sensor disguised as sea turtle egg allows conservationists to remotely predict nest hatching time

A new low-cost sensor designed to look like a sea turtle egg enables scientists to monitor nests remotely and predict when hatchlings will emerge almost to the day, providing valuable information for conservation efforts and management turtle nest. Erin Clabough of the University of Virginia and Samuel Wantman of Nerds Without Borders led the research, which is published Oct. 26 in the open-access journal PLOS ONE.

Sea turtle populations worldwide are declining due to human activities, with Loggerhead, Green, Hawksbill, Kemp’s Ridley, Leatherback and Olive Ridley sea turtles listed as endangered species. Sea turtle conservation efforts are largely focused on protecting the vulnerable hatchlings once they hatch, to ensure they head for the sea, rather than the bright lights of cities. Ecologists can count the days since the eggs were laid to predict when they will hatch and then track the nest, but these efforts are imprecise and labor intensive.

In the current study, researchers used the TurtleSense system to monitor loggerhead sea turtle nests at Cape Hatteras National Seashore to see if they could more accurately predict when the turtles would emerge from the nest. They buried an egg-sized sensor inside the nest and attached a cable to a communications tower that remotely transmitted data about the fledglings’ movement within the nest.

The researchers detected a pattern of intense hatching movement within the nest, followed by a pause, which allowed them to predict almost the exact day the young turtles would dig out of the sand. Their results suggest that hatchlings can detect movement, which allows them to communicate and come out together as a group. The system also accurately identified unviable nests where monitoring was no longer necessary.

The new TurtleSense system has the potential to reduce the cost and labor required to monitor endangered turtle nests and help conservationists make better nest management decisions. The system can also shorten beach closures and allow communities to participate in turtle-based ecotourism, benefiting both the community and sea turtle conservation efforts. While this study focused on loggerhead turtles, the researchers also monitored Olive Ridley and Green Turtle nests and saw similar patterns, suggesting the system will work for a range of sea turtle species.

Erin Clabough adds, “It’s absolutely magical to see baby turtles pop their heads out of the sand and run toward the ocean, but it’s an event that can be very difficult to predict. 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 better predict when the hatchlings will come to the beach.”

Samuel Wantman adds, “As each turtle emerges from its shell, it climbs 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. When there is no more commotion there is a period of quiet, which may be the impetus for all the fledglings to leave the nest together.”