Birds on their first migration rely on the magnetic field and the sun, in future migrations the smells along the route help to guide them.
Adult migratory birds are clearly able to remember migration routes. Even if they end up flying over unknown terrain, they still manage to find their way to the right place. Researchers at the Max Planck Institute for Ornithology in Radolfzell and their colleagues at the universities of Princeton, Pisa and Copenhagen have established in a field study that odours considerably facilitate bird migration and act as a more important navigational cue than the sun and the earth’s magnetic field. ( read more Birds follow their noses during migration )