Birds seem to 'see' magnetic fields while navigating.

The article reports on an experiment on European robins which indicates that birds that navigate using the Earth's magnetic field rely more on their eyes than on magnetic particles in their noses. According to Henrik Mouritsen at the University of Oldenburg, Germany and his team, robins were unable to navigate after the removal of their cluster N, a brain region involved in processing signals from the pair-forming photopigments in the eyes which relay magnetic compass information.