Click to enlarge
A bird nest is the spot in which a bird lays and incubates its eggs and raises its young. Although the term popularly refers to a specific structure made by the bird itself—such as the grassy cup nest.
Bird's nests are among the most expensive animal products consumed by humans. The nests have been used in Chinese cooking for over 400 years, most often as bird's nest soup.
The Chinese name for edible bird's nest, yan wo , translates literally as "swallow's nest", and often serves as a synonym for bird's nest soup, however yan wo strictly speaking is the uncooked nest.
Most nests are built during the breeding season by the male Swiftlet over a period of 35 days. They take the shape of a shallow cup stuck to the cave wall. The nests are composed of interwoven strands of salivary laminae cement. Both nests have high levels of calcium, iron, potassium, and magnesium.