From the article: In the early nineteen-sixties, a German graduate student named Wolfgang Wiltschko began conducting experiments with European robins, which he

From the article: In the early nineteen-sixties, a German graduate student named Wolfgang Wiltschko began conducting experiments with European robins, which he thought might find their way by picking up radio waves that emanated from the stars. Instead, Wiltschko discovered that if he put the robins in cages equipped with a Helmholtz coil—a device for creating a uniform magnetic field—the birds would change their orientation when he switched the direction of north.