Bird's Nest Soup - Harvesting

Harvesting

The most heavily harvested nests are from the Edible-nest Swiftlet or White-nest Swiftlet (Aerodramus fuciphagus) and the Black-nest Swiftlet (Aerodramus maximus). The white nests and the red nests are supposedly rich in nutrients, which are traditionally believed to provide health benefits, such as aiding digestion, raising libido, improving the voice, alleviating asthma, improving focus, and an overall benefit to the immune system.

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.

Hong Kong and the United States are the largest importers of these nests. In Hong Kong, a bowl of bird's nest soup would cost $30 USD to $100 USD. A kilogram of white nest can cost up to $2,000 USD, and a kilogram of red nests 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 a bird nest concession island in Thailand. The high cost and demand has caused many to attempt counterfeiting the soup leading to all exports to China from Malaysia being halted. Therefore, counterfeiting of nests will be prevented as the Malaysian government plans to use RFID technology to keep it protected.

The nests were formerly harvested from caves, principally the enormous limestone caves at Gomantong and Niah in Borneo. With the escalation in demand these sources have been supplanted since the late 1990s by purpose-built nesting houses, usually reinforced concrete structures following the design of the Southeast Asian shop-house ("rumah toko"/"ruko"). These nesting houses are normally found in urban areas near the sea, since the birds have a propensity to flock in such places. This has become an extraordinary industry, mainly based on a series of towns in the Indonesian Province of North Sumatra, which have been completely transformed by the activity. From there the nests are mostly exported to the markets in Hong Kong, which has become the centre of the world trade, though most of the final consumers are from mainland China. It has been estimated that the products now account for 0.5% of the Indonesian GDP, equivalent to about a quarter of the country's fishing industry.

In the Gunung Palung National Park, Indonesia. The swiftlet barns in this area are built from timber, particularly belian and meranti.

• The key ingredient of bird's nest soup

• Bird Nests box showing HK$888.99 price tag

• Ko Lao Liang Tai island, in southern Thailand, where bird nests are collected

• A typical nesting house for swiftlets in Baan Laem, Phetchaburi province, Thailand.