Turtles find home by magnetic super-power
TURTLES return to the same place every year to lay their eggs by sensing the individual magnetic field of the beach where they were born, research has found.
It explains how loggerhead turtles find their way back to their home nesting spot after travelling hundreds of miles out to sea.
Scientists, who studied turtle colonies in Florida, said that the creatures were able to find their ‘home’ by detecting how far north or south their beach was in relation to the strength of the Earth’s magnetic field.
However, the super-power is not foolproof, they said. Researchers from the University of North Carolina at Chapel Hill found that some turtles may have been drawn to the wrong beach because it had a similar magnetic pattern.
The authors of the paper published in Current Biology warn that their findings suggest humans need to be careful when building anything on a beach that might confuse a turtle’s magnetic sense. Structures such as power lines could disrupt it.
In reaching their findings, researchers noted that turtles on one beach on the Florida peninsula were genetically more closely related to turtles separated by hundreds of miles of sea than to others a mile or two away to the north or south on the coast.
To explain this, they said the genetically similar turtles must have laid their eggs on a beach with a similar magnetic pattern.
Professor Kenneth Lohmann, of UNC Chapel Hill, said: ‘Loggerhead sea turtles are fascinating creatures that begin their lives by migrating alone across the Atlantic Ocean and back.
‘Eventually they return to nest on the beach where they hatched – or else, as it turns out, on a beach with a very similar magnetic field. This is an important new insight into how sea turtles navigate during their long-distance migrations.’