INTRODUCTION 

1. Swiftlets – Edible Nest Builder

Swiftlets are easily mistaken for other similar-looking birds, such as the swallows (Hirundo spp) or the House Swift (Apus affinis). Although the swiftlets resemble the swallows and are about the same size, anatomically they are very different:

• -Swiftlets cannot perch.
• -Swiftlets have more rapid and different wing strokes in flight.
• -They are distinctly smaller than the House Swift, which builds nest of mixed feathers and other materials, loosely bound together.
• -Swiftets have superb eyesight, short bill but wide gape.
• -They feed entirely on small airborne insects, which they track and catch in the flight.
• -They also drink on the wing.
• -There is even evidence that they can copulate on the wind.

The shape, positioning and structure of the nest and the composition of material used are distintive of each species of swiftlets in the Borneo. One builds unmarketable, inedible nests: the nest of the Mossy-nest Swiftlet (Aerodramus Salanganus) is small, shallow bowl-shaped, made of compressed vegetation, and always placed on a ledge or in small concavity of the cave wall.

The edible nest of other Borneo swiftlets are self-supporting, half-cup shaped structures, adhering to the wall of the cave or other chosen site. Those of the highest quality, called 'white' (putih) or 'silver' (perak) nests are made almost entirely of pure hardened saliva.

The 'black' nests (sarang hitam or manas) incorporate many feathers from the birds' own plumage, comprising up to half of the bulk of the nest. While glossy swiftlets use extraneous materials such as strands of moss or leafy liverwort, lichens, grass-blades or seed heads, and a variety of other strands of vegatation.

Swiftlets eggs are aval in shape, and all species lay pure white eggs: camourflage coloration is unneccessary inside the darkness of caves!

2. The chemical constitution of Edible Birds’-Nest

The composition of edible birds’-nest averages: