A Conversation with Peter Hore

M igratory birds make epic journeys of thousands of miles each year, navigating with the help of Earth’s magnetic field. Yet the mechanism behind the biological compass that enables them to achieve this astonishing feat remains a mystery. Peter Hore of the University of Oxford is a leading proponent of the idea that this magnetic sense depends on chemical reactions involving excited radicals produced in a protein in the birds’ retinas. Mark Peplow spoke to him about the growing body of evidence behind the theory.