The white stork migrates between Europe and Africa and often uses the Strait of Gibraltar to avoid crossing the Mediterranean.
White storks depend on rising columns of warm air, called thermals, to soar with little wing flapping. Because thermals form mainly over land, many European birds funnel through Gibraltar in the west or the Bosphorus in the east instead of taking a long, energy-intensive flight over open sea.
European white storks usually winter in sub-Saharan Africa. Their broad wings and soaring lifestyle make geography especially important: narrow land routes can concentrate thousands of migrants at particular locations. The species also uses open farmland, wetlands, grasslands, and rubbish tips while travelling.
The black stork is a separate, more secretive species with darker plumage and different habitat preferences. White storks are also culturally associated with nest-building on rooftops, chimneys, and poles, although natural nests occur in trees and cliffs.