Autumn (September–November, solid line) and spring (February–June, dashed line) migration routes of the 16 black storks between Europe and Africa (autumn, solid line; spring, dashed line). Average wind azimuths (dashed line) are added on the map. Red dotted line, wind azimuth in spring (Europe); blue dotted line, wind azimuth in autumn (Europe); green dotted line, wind azimuth in autumn (Africa); black dotted line, wind azimuth in spring (Africa).