Ballester - Vencejo rea - Alpine swift
Spectacular and distinctive large, dark brown swift with white belly and throat patch. Noticeably larger than Common Swift and Blyth’s Swift, but with slower wingbeats and a "lazier" and wider soaring flight. Breeds colonially in cliff faces, mountains, and larger buildings. Migratory in parts of its range. Call is an extremely shrill, chittering scream.