Biology
Migratory Navigation Using Magnetic Field Sensing in Sea Turtles
Quick fact
Sea turtles can sense the Earth's magnetic field and use its variations in intensity and inclination as a kind of 'magnetic map' to find their way back to their natal beaches—even from thousands of kilometers away. This magnetic map sense is so precise that they can distinguish different coastal regions by their unique magnetic signatures.
Why this is interesting
How can a sea turtle that hatched on a single beach find its way back to that same beach years later, after wandering thousands of kilometers across the open ocean? The answer may lie in an invisible global grid that ancient mariners used only with the help of instruments.