The highly migratory swift Apus apus of the Palaearctic winters wholly within the Afrotropics south of c. 9 S., and is currently considered to comprise only two moderately well - differentiated subspecies A careful examination of specimens from south - central and southern Africa suggests that three subspecies should now be recognised in line with Hartet's arrangement of the species in his Die Vögel der palaarktischen Fauna of 1912, these being satisfactorily distinguishable on wintering material. The taxon A. a. marwirzi, described from Tanzania, is re - instated and its revised characters laid down. (Author's summary).