Nesting sea turtles require a delicate ecological mix: the right sand, the correct temperature and an easily accessible beach with few predators. To be sure of laying their eggs in the best place, the turtles go back to the beach where they hatched themselves – if it worked for their mothers, so it should work for them.
By studying nesting sites in Florida, a team from the University of North Carolina has discovered that the turtles seek out unique magnetic signatures along the coast. As hatchlings, they imprint on the magnetic field of their natal beach and then use this information to return as adults.
But exactly how they detect the geomagnetic field is still not known. The most likely way is via tiny magnetic particles in the brain that respond to the Earth’s field and give the turtles a ‘magnetic sense’.
Do you have a wildlife question you’d like answered? Email your question to email@example.com or post it to Q&A, BBC Wildlife Magazine, Immediate Media Company, Eagle House, Bristol, BS1 4ST.