Swiftlet / Black-Nest / Edible-Nest / White-Nest (Aerodramus maximus / Aerodramus fuciphagus)
Order: Apodiformes, Family: Apodidae
The swiftlet is a cave-dwelling bird.
It is dull brown or gray in color, and paler on the rump and underpart. Swiftlets grow to be 3 1/2 to 6 inches long (the size of a sparrow), and weigh about half an ounce.
Swiftlets fly lower, more slowly and more erratically than most swifts. They are small swifts, a family superficially similar to swallows, but with longer, more slender, scythe-like wings.
II. GEOGRAPHICAL RANGE AND HABITAT:
- The swiftlet is a cave-dwelling bird.
- It is dull brown or gray in color, and paler on the rump and underpart. Swiftlets grow to be 3 1/2 to 6 inches long (the size of a sparrow), and weigh about half an ounce.
- Swiftlets fly lower, more slowly and more erratically than most swifts. They are small swifts, a family superficially similar to swallows, but with longer, more slender, scythe-like wings.
- Swiftlets inhabit Southeast Asia and the Indian subcontinent.
- The live mostly in mountain or coastal caves, and sometimes open areas and towns.
IV. LIFE CYCLE/SOCIAL STRUCTURE:
- Swiftlets eat flying insects, which they catch in midair.
V. SPECIAL NOTES/ADAPTATIONS:
- Colonies may contain up to a million birds.
- Swiftlets breed in caves.
- During breeding season, a swiftlet's salivary glands enlarge enormously, enabling the bird to produce the saliva that binds the nest, which takes approximately two months to construct and usually holds one egg.
VI. EFFECT ON HABITAT:
- Cave-dwelling swiftlets are the only birds to use sonar in maneuvering through darkness. Its sonar consists of clicking sounds at frequencies of 1,500 to 5,500 hertz — audible to the human ear. The sounds are emitted at the rate of about six per second. (Swiftlets are the only true avian troglodytes — cave dwellers.) Not only can they navigate in total darkness, but they can find their own individual nest among hundreds of others.
- A swiftlet nest resembles a small bracket, sometimes containing bits of fern or bark. The male regurgitates a long, thin gelatinous strand from salivary glands under its tongue, which is then wound into a half-cup nest and bonds like quick-drying cement to the inside of a cave wall.
VII. POPULATION STATUS:
- Guano deposited by swiftlets (and many species of bats) gives rise to a whole community of insects that draw energy from the guano and the corpses of the flying animals.
- The rising price and demand for swiftlet nests for "bird's nest soup" has resulted in a decline in the swiftlet population. In most nest-producing countries, swiftlet colonies are dwindling. It is argued that if harvesting continues at its current rate, the species may die out in five to 10 years. Since 1934, an ordinance in Sarawak permits the nests to be harvested only every 75 days. Similarly, in Sabah, only two harvests per year of the white-nest swiftlets are allowed.
- The edible-nest swiftlet is also known as the white-nest swiftlet and the brown-rumped swiftlet. Its whitish-yellow nest is bound almost exclusively by saliva.
- The black-nest swiftlet is larger than its 2-inch-deep, "half-saucer"-shaped nest — when it sits in the nest, it faces the cave wall, while its tail and long, folded wings stick out into the air. Its nest is made with saliva and feathers.