Swiftlet
A small swift in the genera Aerodramus, Collocalia, or related groups. Many swiftlets nest in caves and use echolocation to navigate in darkness.
Echolocation in swiftlets: A biological sonar system in which swiftlets emit clicks and use returning echoes to orient themselves, especially in darkness. It lets cave-nesting species navigate passages where vision alone is insufficient.
Swift: A fast-flying bird in the family Apodidae, adapted to spend much of its life on the wing. Swiftlets are small members of this broader bird family.
Edible bird's nest: A food made primarily from the hardened saliva nests of certain swiftlets, especially species in Aerodramus. The nests of selected swiftlets are harvested, processed, and sold as a delicacy.
Edible-nest swiftlet: A swiftlet species, Aerodramus fuciphagus, whose largely salivary nest is harvested for edible bird's nest. It is one of the principal species behind the commercial edible-nest trade.
Swiftlet nest: A nest built by a swiftlet, often from hardened salivary secretions attached to a cave wall or other surface. Its materials and construction vary among species and underpin the edible-nest trade.
Apodidae: The bird family that includes swifts and swiftlets, characterized by specialized aerial adaptations. Swiftlet genera belong to this family, though their classification has been revised.
Bird's nest soup: A Chinese soup whose gelatinous ingredient is edible bird's nest, usually reconstituted and simmered. Demand for this dish drives much of the commercial value of swiftlet nests.
Black-nest swiftlet: Aerodramus maximus, a cave-nesting swiftlet whose nest contains substantial feathers as well as saliva. Its darker, feather-rich nest contrasts with the nearly all-saliva nest of the edible-nest swiftlet.
Salivary gland: An organ that produces saliva, whose proteins and secretions serve functions including lubrication and nest construction in some birds. Enlarged glands supply the secretion used by edible-nest swiftlets to build nests.
Aves: The class of vertebrates comprising birds, characterized by feathers, beaks, and egg-laying. Swiftlets are birds whose anatomy and reproduction follow the wider avian pattern.