October 1, 2007 -- Birds May See Earth's Magnetic Field

Millions of birds each year heed the call of changing seasons and migrate thousands of miles from one feeding ground to another. Scientists have shown that the earth’s magnetic field helps guide them. But how? Research now suggests that birds may literally see this magnetic fly plan. Scientists at a university in Germany previously demonstrated that a particular molecule that senses magnetism exists in birds’ eyes. A later study showed that these molecules and a frontal part of the brain are active in the presence of a magnetic field. Now, their latest study links the two. They published their results in the journal Public Library of Science ONE.

The researchers traced the path of the neurons from the eyes into a specific part of the brain.  Both the path and the brain region are active during magnetic orientation. The tracers attached to the neurons showed that these areas are linked by a well-known brain circuit involved in vision. The scientists caution this isn’t definitive proof. But it is a pretty strong suggestion that birds can somehow see their way along the magnetic fields that surround the globe. That’s quite a bird’s eye view.