Open Ocean Reorientation and Challenges of Island Finding by Sea Turtles during Long-Distance Migration

Sea turtles are not the best navigators

30 November 2020

The ability of sea turtles to navigate back to regular feeding grounds is less accurate than previously thought.

Green sea turtles return faithfully to the same locations to forage after nesting, sometimes swimming thousands of kilometres across open ocean to small islands or submerged banks. How they navigate to such isolated locations has not been well understood.

Now, a team led by a researcher from Deakin University in Australia has tracked the movements of 33 green sea turtles.

They found that the reptiles often wander off course, sometimes overshooting their target by hundreds of kilometres or landing on the wrong island. They were then seen to double back, search haphazardly or ‘island hop’ to their intended destination.

This suggests the turtles have fairly imprecise navigation abilities, but course correct in the final stages of migration to reach their foraging grounds.

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References

1. Current Biology 30, 3236–3242 (2020). doi: 10.1016/j.cub.2020.05.086