THE SECRET OF HOMING PIGEONS IN A BRAIN-BEAK CONNECTION
Mora et al. (Magnetoreception and its trigeminal mediation in the homing pigeons. Nature 432, 508-511, 2004) suggest that magnetite in the upper beak region is used to detect the magnetic field and the trigeminal nerve (V) relays this information to the brain.
The idea that homing pigeons use magnetoreception is not new, but the physiological mechanism by which they can find their way home is far from being known.
Mora’s group trained pigeons to detect a magnetic field anomaly and found that this ability was impaired by anaesthetizing the upper beak or attaching a magnet to it, or by severing the ophthalmic branch of the trigeminal nerve.