Birds may have internal GPS

Nature : Although many animals use Earth’s magnetic field for spatial orientation and navigation, how they do that remains a mystery. It has been proposed that magnetic sensors in the eyes, beaks, noses, or ears relay magnetic field information to the brain. According to research published online yesterday in Science, David Dickman and Le-Qing Wu of Baylor College of Medicine in Houston, Texas, show that the inner ear lagena of birds may be linked to magnetoreception. In their experiment, they placed seven homing pigeons in a dark room. While creating and rotating carefully controlled artificial magnetic fields around the birds, the researchers monitored the birds’ brain activity. They found that the birds’ “vestibular neuronsâmdash;which are linked to balance systems in the inner earâmdash;fired differentially in response to alterations in the field’s direction, intensity and polarity, and that these cells were especially sensitive to the bandwith that covers Earth’s geo-magnetic field,” writes Daniel Cressey for Nature.