The Genius of Birds

by Jennifer Ackerman

One model holds that birds “see” magnetic fields with special molecules in the retina activated by certain wavelengths of light. Magnetic signals seem to affect the chemical reactions of these molecules, either speeding them up or slowing them down, depending on the direction of the magnetic field. In response, the retinal nerves fire signals to the visual areas of a bird’s brain, making it aware of the field’s direction. It all occurs at the subatomic level, involving the spinning of electrons, which suggests something extraordinary: Birds may be capable of sensing quantum effects. The sensing seems to involve a part of the forebrain linked to the eyes, known as cluster N. If cluster N is damaged, birds can no longer sense which way is north.