Adult Male:
The area in front of and below the black eyes is dark. The face has dark purple-brown ear patches, chin, and throat. A faint, unclear pale eyebrow stripe is present above the eye. The back is pale grayish-blue. The forehead crest is dark gray with a greenish sheen. The wing coverts are dark gray with a greenish or pale blue sheen. The flight feathers and tail feathers are dark brown with a pale greenish sheen. The area between the throat, chest, and flanks is pale grayish-blue, transitioning to white on the belly and under-tail coverts.
Adult Female:
The chin, face, sides of the head, and throat are gray, dark in front of the eyes, gradually transitioning to dark gray on the ear patches. The eyes are dark brown; the eyelids are lead-gray. The beak is black. The legs are dull pinkish-brown.
Measurements:
Wing: 151 – 165 mm; Tail: 117 – 135 mm; Tarsus (leg): 7 – 8 mm; Beak: 7 mm.
Distribution:
The Crested Swift is distributed in Sri Lanka, India, Assam, Myanmar, Thailand, and Indochina.
Vietnam:
This species is found in Ninh Thuan, Bien Hoa, Thu Dau Mot, and the Central Highlands.