Fig. 1

Hypothetical onward migration routes of Common Blackbirds, European Robins (both medium-distance migrants) and Northern Wheatears (long-distance migrants) departing from Helgoland (white dot) during autumn. Arrows figure simplified hypothetical migration routes towards the species-specific wintering grounds as derived from ring recoveries of birds ringed on Helgoland (Common Blackbirds and European Robins [35]) or estimated wintering locations from light-level geolocation data of European breeding birds (Norther Wheatear [36]). Maps represent an orthographic projection with Helgoland as the projection centre. Species distribution data were provided by BirdLife International [37]