Earth’s magnetic field guides sea turtles home | Science News

Support Science Journalism

Science News is a nonprofit.

Support us by subscribing now.

Mystery Solved

Earth’s magnetic field guides sea turtles home

Slight shifts in loggerhead nesting grounds reveal how the reptiles navigate

12:00pm, January 15, 2015
Caretta caretta sea turtle

HOME AGAIN  Sea turtles use Earth’s magnetic field to pinpoint their nesting beach, a new study finds.

Loggerhead sea turtles traverse entire oceans in search of jellyfish and other scrumptious food. But at nesting time, they always find their way back to the very same stretch of coast where they hatched.

Now scientists know how turtles accomplish the feat: They recognize their home turf using Earth’s magnetic field, which varies across the globe.

Although long suspected, this hypothesis had been challenging to test. J. Roger Brothers and Kenneth Lohmann of the University of North Carolina at Chapel Hill realized that if turtles homed in on beaches’ unique magnetic signatures, their nests should migrate in response to subtle natural changes in the geomagnetic field. Over 19 years, the scientists found that the nests of sea turtles in Florida clustered more densely in places where magnetic signatures got closer together and spread out where signatures drifted apart, the researchers

This article is only available to Science News subscribers. Already a subscriber? Log in now.
Or subscribe today for full access.

Get Science News headlines by e-mail.

More from Science News

From the Nature Index Paid Content