About This Project

During the mass nesting of sea turtles, thousands of turtles emerge from the ocean to lay their eggs along a small stretch of beach. Despite our fascination with this natural phenomenon, almost nothing is known about how sea turtles manage to synchronize their behavior in this way. Our experiment will test whether sea turtles use olfactory cues to coordinate mass nesting behavior. Our results will inform conservation management to protect the future of this incredible natural phenomenon.

Ask the Scientists

What is the context of this research?

Although this natural phenomenon has captivated our attention for decades, almost nothing is known about the mechanisms that enable turtles to synchronize their behavior so that thousands emerge from the sea to lay their eggs at the same time and place [1]. One possibility is that mass nesting is coordinated by chemical secretions, known as pheromones, that influence the behavior of other individuals [2, 3]. The idea that a rising level of pheromones in the water might trigger mass nesting is plausible given that reptiles have well-developed olfactory senses and can perceive diverse chemical cues, including some that involve social behavior [4]. Our pilot experiment (featured in our video) tested an alternative low-cost approach and identified the need for the use of tracking technology.

What is the significance of this project?

This unique and fascinating behavior occurs at only several beaches in the world and several mass nesting populations have disappeared due to overexploitation [1]. Given the difficulty in predicting the timing of mass nesting events, local authorities struggle to control the sporadic tourism that coincides. In fact, our study site recently received international attention for its failure to control tourists [5]. By tracking sea turtles and increasing our knowledge of the mass nesting behavior, our experiment will allow management to predict events, identify potential threats, and allocate limited funding and resources more appropriately to ensure the future of this incredible natural phenomenon.

What are the goals of the project?

We will test whether sea turtles use olfactory cues (such as pheromones) to coordinate mass nesting behavior. We will capture female sea turtles in offshore waters in the days just prior to an expected nesting event. We will randomly treat the nostrils of these sea turtles with either ZnSO₄ or saline. ZnSO₄ temporarily interrupts olfaction in marine turtles without harming the turtle or affecting its behavior [6]. We will tag each turtle with a transmitter and track females to monitor whether individuals emerge to nest. After the conclusion of the nesting event, we will relocate and recapture all tagged turtles to retrieve transmitters. If olfactory cues are involved with the synchronization of nesting, we would expect the sea turtles treated with ZnSO₄ to lag behind in nesting.