Migrating birds use a magnetic map to travel long distances
Richard Holland, The Conversation
Much of the research has focused on homing pigeons, which are famous for their ability to return to their lofts after long distance displacements. Evidence suggests that pigeons use a combination of olfactory cues to locate their position, and then the sun as a compass to head in the right direction. Over these vast distances, the cues that pigeons use may not work for migrating birds, and so scientists think they may require a more global mapping mechanism. To find out whether declination is used by migrating birds, we tested the orientation of migratory reed warblers. This was not consistent with a magnetic compass response, but was consistent with the birds thinking they had been displaced to Scotland, and correcting to return to their normal path.