Are you interested in knowing swiflet sub-species?
Here an article for reference,
--- In swiftlets@yahoogrou ps.com, Ben Chai
> Hi Jeff,
> The house swiftlets is being classify as either a sub species or a
hybrid and is being renamed by Lord Cranbrook
as" fuciphagus domesticus". They as the name suggest are
domesticated although share the same food source as their cave
cousins , their nesting habits and even their nest compositions are
different. They no longer can survive and nest in caves but prefer to
co exist with human. This benefits both bird and man we provide
housing and they pay rental with their abundant nest. Win Win for
all... Pls. read my article in World Of Swiftlets Farming.