About 50 animal species, ranging from birds and mammals to reptiles and insects, use Earth’s magnetic field for navigation.
Yet Earth’s magnetic field is very week. It ranges from approximately 30 to 60 millionths of one tesla. By comparison, magnetic resonance imaging, or MRI, uses magnetic fields from 1.5 to 3.0 tesla.
So scientists unsure exactly how birds do it.
New research finds that a photochemical compass may simulate how migrating birds use the magnetic field, along with light, to navigate.