Fig. 2

Maps showing GPS-tracks of European nightjars in autumn (left) and spring (right). For illustrative purpose, five individuals with tracks recorded from multiple seasons are highlighted with different colours, all others are depicted in grey. Dashed lines mark the latitudinal extents of the barriers as presented in the study (see Fig. 5 and Table 1): i = Baltic Sea, ii = The Alps, iii = Mediterranean Sea, iv = Sahara Desert, v = Tropical rainforest