White-nest Swiftlet

The edible-nest swiftlet, generally with a body length of 14 cm (5.5 in), is a medium-sized representative of the salanganes. The upper part of the slender body is blackish-brown; the under part of the body ranges in colour from white to blackish-brown. The tail is short and has a slight notch. The bill and feet are black. Legs are very short and tarsi are usually unfeathered or lightly feathered. It weighs 15 to 18 g (0.53 to 0.63 oz) and the wings are long and narrow. In flight the swept-back wings resemble a crescent. The subspecies micans is paler and greyer than the nominate while vestitus is dark with a rump that is less obviously paler. Subspecies germani has much paler underparts with a broad whitish rump, amechanus is similar to germani but has a greyer rump.

The edible-nest swiftlet feeds over a range of habitats from coastal areas to the mountains, occurring up to 2,800 metres above sea-level on Sumatra and Borneo. These birds generally occur above forests, the forest edge, but also in open country. These birds spend most of their lives in the air. Their diet consists of flying insects that are caught on the wing. They also drink on the wing. They often feed in large flocks with other species of swiftlet and swallow. They breed in colonies in coastal areas, in limestone caves, in rock crevices, in a cleft in a cliff or sometimes on a building. The bracket-shaped nest is built on a vertical surface and the long legs are used for clinging. These swifts never settle voluntarily on the ground. The nest is white and translucent and is made of layers of hardened saliva attached to the rock. A nest typically measures about 6 cm across with a depth of 1.5 cm and a weight of about 14 grams. Two white, oval, non-glossy eggs are laid. At breeding colonies, the birds emit high-pitched and burbling calls. They also emit a rattling call used for echolocation, which enables them to look for their nesting sites in the darkness of caves.