Bird’s nest soup is a delicacy in Chinese Cuisine. A few species of swift, cove swifts, are renowned for building the saliva nests used to produce the unique soup.

The edible 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 most heavily harvested nests are from the White-nest Swiftlet (Aerodramus fuciphagus) and the Black nest swiftlet (Aerodramus maximus).

The white nests and the “red blood” nests are rich in nutrients and provide several health benefits. They aid in digestion, raise the libido, improve the voice, alleviate asthma, improve focus and benefit the immune system.

The nests are built during the breeding season by the male swiftlets 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.

In Hong Kong, a bowl of bird’s nest soup would cost from $30 to $100 USD.A kilogram of white nest can cost up to $2,000 USD, and a kilogram of “red blood” nest can cost up to $10,000 USD.

The white nests are commonly treated with a red pigment, but methods have been developed to determine an adulterated nest. Natural red cave nests are often only found in limestone caves in Thailand.

The nests were formerly harvested from caves.With the escalation in demand, these sources have been supplanted since the late 1990s by purpose-built nesting houses.

These nesting houses are normally found in urban areas near the sea, since the birds flock in such places.

From there the nests are mostly exported to Hong Kong, which has become the center of the world trade, though most of the final consumers are from mainland China.

This potentially environmentally sustainable industry is contributing to deforestation in Indonesia, The swiftlet barns in this area are built from copious quantities of timber

Since the legal timber supplies are inadequate to meet demand illegal logging has grown in the National Park.