what is birds nest?

Edible Bird’s Nest (EBN) is hardened salivary material secreted by the male birds of several species of swiftlets during nest building. The birds secrete saliva and use it as cementing material to bind feathers and vegetation together, and shape them into nests with attachment to the walls of inland or seaside caves. Often nest weighs 1-2 times the swiftlet’s body weight. It only supports the mother and the nestlings. The nest construction is completed in 35 days.

Traditionally, EBN is classified both before and after processing. The commonly used classification of EBN is based on the nest’ external morphological features such as size, shape, feathering, appearance and colour.  On the basis of shape,  edible birds nest 9EBN) has been categorised into several types such as nest cup, nest cake and cracked pieces nest. Consideration of the size of nests gives rise to one more class of EBN, fingers grade (unprocessed nest).

EBN can also be divided into cave nest and house nest. Cave nests are mainly harvested from natural caves, whereas house nests are made by swiftlets in the attic of countryside houses.  Cave nests are harvested by local people via a complex system of management and ownership. The nest harvesting process is often painful and risky. The use of nest harvesting techniques depends on several factor such as the cave site, cave height above the ground or water bed, and some other related factors.

Due to the fact that cave nests are made by free and naturally-living swiftlets, some people considered them to be more valuable than house nests, and, hence, fetch a higher price. However, in reality, cave nests generally contain more foreign materials and feathers than house nests. Cave nest are exposed to the risk contamination by heavy metals from the external environment. The texture of house nests is usually smoother as compared to that of cave nests. Besides, the house nests have less feathers and other contaminants in comparison to the cave nests.

Good quality nests are distinguished by a comparatively large proportion of nest-cement with few feathers in the nest—cup.