Figure 2.

Longitudes (average, bold line; s.d.: thin line) of Dutch pied flycatchers before and after diurnal flight (see the electronic supplementary material, table S1) roughly indicate onset locations and destinations of non-stop flight. Latitudes prior to diurnal flight were chosen to include fuelling sites in autumn (Iberia, less so North Africa) or spring (wintering range). Latitudes after diurnal flight indicate possible destinations, assuming 15.3 m s⁻¹ flight speed and the maximal flight duration (electronic supplementary material, table S1). Wintering longitude (average±s.d.) is depicted in white.