Displacement studies have shown that long-distance, night-migrating
songbirds are able to perform true navigation from their first spring
migration onwards. True navigation requires both a map and a compass. Whereas birds are known to have sun, star, and magnetic compasses, the nature of the map cues used has remained highly controversial. There is quite strong experimental evidence for the involvement of olfactory map cues in pigeon and seabird homing. In contrast, the evidence for the use of magnetic map cues has remained weak and very little is known about the map cues used by long-distance migratory songbirds. In earlier experiments, we have shown that Eurasian reed warblers physically displaced 1,000 km eastward from Rybachy to Zvenigorod re-orient towards their breeding destinations by changing their orientation in Emlen funnels from the NE to the NW. We have also previously shown that this re-orientation cannot be explained by a ‘jetlag effect’. We have now used this model system to show that Eurasian