Tenggara Swiftlet

The Tenggara swiftlet is 9–10 cm (3.5–3.9 in) in length with a square tail. The back and upper surface of the wings are dark blue with a moderate gloss. The rump is generally dark but sometimes includes feathers with thin white edging. The throat and upper breast are grey with fine white scalloping merging into larger greyish chevrons over the lower breast and flanks, becoming white over the belly. There is occasionally a tuft of small feathers on the hallux, the rear facing toe.