
Photo: sunnyjosef · CC BY 4.0 (May be cropped or resized)
Cypsiurus balasiensis
Habitat
Nest glued under a palm leaf
Clutch size
Usually 2–3 eggs
Size
About 13cm
The Asian palm swift is a small swift about 13cm long and mainly pale brown. The down-and-feather nest is glued to the underside of a palm leaf with saliva, which is also used to secure the usually two or three eggs (Wikipedia, general species account).
The source read for the Bhutan guide gives only the colour, size and nest, with nothing on range, voice or habitat beyond the palm nest, so no more is stated. Its occurrence in Bhutan is flagged for checking.