They never settle voluntarily on the ground, and spend most of their lives in the air, feeding on insects that they catch in their beaks.

Plain swifts breed in colonies on cliffs, bridges and buildings on the Canary Islands and Madeira, laying two eggs in a saucer-shaped nest made of flowerheads glued with saliva.

Small numbers are also believed to breed in Morocco between Agadir and Essaouira, where a colony was found on coastal cliffs and possibly also in Mauritania where there are frequent sightings.

[2] This 14–15 cm long species is very similar to the closely related common and pallid swifts, which also occur in the archipelagos, and separation is only possible with good views.

The plain is slimmer and appears longer winged than the common, and has scaly underparts, difficult to see except with excellent views.