Doris,

I lived in southeast Asia where these birds are native. Nesting in the wild they produce a money-making harvest, although most of the money goes to the middlemen rather than the poor locals who literally risk their lives to reach the nests. When this is regulated the harvests are sustainable, but I would like to see safer ways to collect the nests. However some people are more greedy and found that special 'houses' can be built to get swiftlets to nest in more convenient places, and in greater numbers. Now, swift houses have been built in places where they do not occur naturally, and the swiftlets have been taken to these areas to produce swift 'farms'. There are a number of species of swiftlet, most of which do not make nests considered commercially viable. The imported Edible-nest Swiftlet will compete with native species of swiftlet and other aerial plankton feeders for food. This may upset long-established food webs, perhaps leading to the extirpation of some native species. The process may be enhanced by the swiftlet-farmers destroying native competing species.

Clive Mann