Sea turtles use the Earth’s magnetic field to navigate, but they may not be very good at it. Scientists put GPS trackers on 22 hawksbill turtles in the Indian Ocean. They found that most used circuitous routes and traveled at least twice as far as they needed to.
Some species of sea turtles migrate thousands of miles, but hawksbills only travel an average of about 100 miles each way. One of the turtles traveled over 800 miles to get to their destination 100 miles away! This suggests that their sense of direction is not finely tuned. And, like humans, some turtles are worse than others at navigating.
Many migrating animals, including sea turtles, don’t forage for food in the same area as they breed. This means that when they leave nesting grounds, they may have hardly eaten for months. If their sense of direction was perfect, they would take the most direct route back to their feeding grounds.
Scientists tagged the hawksbill sea turtles as they left their nesting grounds on Diego Garcia Island in the Indian Ocean. They concluded that the turtles have only a crude sense of direction, enough to correct themselves if they go far off course. The Journal of the Royal Society Interface published the peer-reviewed research, which we learned about from The Guardian.
Scientists use GPS trackers to study many wildlife species and learn more about their migrations and behavior. Everything from Arctic foxes to whale-dolphin hybrids go about their lives while sending satellite data of their whereabouts. Turtle scientists have even used decoy sea turtle eggs to track down poaching operations.
Next time you watch a nature documentary or hours of ocean critter videos, remember that those majestic sea turtles may actually be super lost. Or perhaps the tagged individuals are just messing with the scientists!
Melissa is Nerdist’s science & technology staff writer. She also moderates “science of” panels at conventions and co-hosts Star Warsologies, a podcast about science and Star Wars. Follow her on Twitter @melissatruth.