The birds’ nests which the Chinese use as an ingredient to make their famous birds nest soup are built by a swift belonging to the group of birds known as Collocalia. This bird closely resembles the swallows of Europe.

These swifts are great fliers. They make their home on steep cliffs that rise out of the sea in the islands of eastern Asia. The birds build their nests among these rocks and two or three times a year the nests are gathered to be sold in Chinese markets.

The work of gathering these nests is quite dangerous because very steep cliffs have to be scaled to reach them. Once a colony of nests has been reached they can be removed quite easily. The shelf-like nests are made of saliva of the birds, which goes hard rapidly. It is this saliva, softened by soaking and then cooking, that is used in making the delicious soups.