- Migratory pied flycatchers use a combination of genetics and environment to determine their wintering destinations.
- Birds from different European populations follow consistent, non-direct routes to Africa, with Siberian birds taking a long detour via Spain.
- Experiments moving Dutch flycatchers to Sweden showed wintering location is partly inherited and partly influenced by upbringing.
- Migration routes are shared, but the length of the journey, not the direction from breeding areas, may be fixed.
- The behavior is not learned from parents, which is key for understanding adaptation to climate change.