Plain Swift (Apus unicolor) [XC196532]
by Yoann Blanchon from Cani\u00e7o, Madeira, Madeira, Portugal (call)
Plain Swift (Apus) [XC722154]
by SonoNatura from Isla de la Palma (near Tazacorte), Santa Cruz de Tenerife, Canarias, Spain (call, flight call)
Subspecies
Forms superspecies with Common Swift (Apus apus) and Nyanza Swift (Apus niansae) and has been considered conspecific with both, and also with African Swift (Apus barbatus). In past, considered conspecific with Alexander's Swift (Apus alexandri). Subspecies poensis of Scarce Swift (Schoutedenapus myoptilus) formerly treated as subspecies of this species.