Description

A bird with sickle-shaped wings, resembling a large swallow, and almost always observed in flight. Although it is easily distinguishable from swallows and martins, the Plain Swift can easily be confused with its congener, the Common Swift. Although the distinction is quite difficult, the noticeably paler aspect, the narrower and very pointed wings and the longer and more deeply forked tail are the main characteristics that allow the identification of this species. Still, the best way to distinguish this swift, rare in mainland Portugal, is by its phenology, since it is the swift that can most easily be observed in Portugal during the winter months. It should be noted that there are some records of Common Swift and Pallid Swift during the winter and that the phenology of the Plain Swift is not yet well known in Portugal, since its presence on the mainland was only recently detected. The subtle differences between juvenile and adult plumages make it difficult to assign ages to individuals in flight. This species has no sexual dimorphism.