What is a "swiftlet"?

A swiftlet is a small, agile bird found in various parts of the world, particularly in tropical and subtropical regions. They are known for their swift and acrobatic flight and ability to navigate through narrow spaces with remarkable precision. With their slender bodies, long wings, and forked tails, swiftlets are superb aerial hunters, feeding on insects while in flight. Many species of swiftlets are known for their unique nest-building behavior, constructing edible nests made of saliva, which are highly prized in some cultures for their culinary and medicinal value. These sociable birds often gather in large flocks, creating impressive aerial displays as they maneuver through the skies.