By Susan Milius
A background buzz of electromagnetic waves from such ordinary sources as electronic equipment can interfere with a bird’s magnetic compass, according to a particularly careful set of experiments.
Normally, migratory birds held in captivity during their travel season tend to hop, face and fidget in the direction they would fly. But caged in huts at a German university, European robins (Erithacus rubecula) failed to orient in their usual migratory direction unless researchers screened out the campus’s background electromagnetic frequencies, says Henrik Mouritsen of the University of Oldenburg in Germany. Yet the robins oriented normally in a rural area with less electromagnetic background, he and colleagues report May 7 in Nature.