How do sea turtles find their eggs?

In the new study, the scientists surveyed the 19-year record database of the sea turtle Caretta caretta. They nest along the east coast of Florida, USA, home to the largest sea turtles in North America. The turtles swim thousands of kilometers to where they were born to spawn using special magnetic signs along the coast.

Sea turtles nest at Melbourne beach, Florida, USA.(Photo: J. Roger Brothers)

"We believe that, if sea turtles use magnetic fields to find spawning sites, the natural changes of the Earth's magnetic field may also affect where turtles nest," Live Science quoted J. Roger Brothers as belonging to University of North Carolina, USA, said.

Figures for the 1993-2011 period confirm the idea. At the time of the Earth's magnetic field shifting in some places, the signal from the field near the beach moves closer and the turtles often cover these areas. Similarly, they are less dense and farther apart where there are signs of magnetic separation.

The team has not yet determined how the magnetic field is detected. However, magnetic particles in the brain can help them deal with signs.

"The only way a female turtle can be sure of finding a good place to grow eggs is to nest on the same beach where they are born. The logic of a sea turtle is if that ever worked for me, it will work for my children , " said Brothers.

Many previous studies have shown that sea turtles use Earth's magnetic field to orientate at sea. However, they have not yet shown whether the magnetic characteristics will help sea turtles find where their mothers previously selected.