Learning the Hard Way: Imprinting Can Enhance Enforced Shifts in Habitat Choice

Figure 1

Landscape types (1 = mixed or coniferous forest, 2 = deciduous forest, 3 = agricultural land) and distribution of Ficedula flycatcher nest-box areas (blue circles) on the Swedish island of Öland. The large circle represents nine nest-box areas surrounding the town of Löttorp where collared flycatchers started to colonize the island (and where pied flycatchers were already present) in the late 1950s–early 1960s. Collared flycatchers now outnumber pied flycatchers in this area (~90% collared flycatchers). The relative proportion of collared flycatchers gradually declines southward. Two of the nest-box areas in the north of the island are dominated by coniferous forest and so far only inhabited by pied flycatchers.