The Indian swiftlet, known scientifically as Aerodramus unicolor, is a diminutive and agile bird, a common resident colonial breeder in the verdant hills of Sri Lanka and southwest India. This species, measuring a mere 12 cm in length, is predominantly dark brown above with a paler brown underbelly. Its wings are swept back in a distinctive crescent shape, resembling a boomerang, and the body is slender. The tail is short and exhibits only a slight indentation.
When observing the Indian swiftlet, look for its dark brown plumage and paler underside. The bird's wings are a key identifying feature, with their unique crescent or boomerang shape. Both sexes and juveniles share a similar appearance, making sexing in the field a challenge. Note the bird's very short legs, adapted for clinging to vertical surfaces, as swifts are known to avoid settling on the ground voluntarily.
The Indian swiftlet favors the hilly regions where it can find suitable vertical surfaces, often within caves, to construct its nests.
These swiftlets are almost exclusively aerial, spending the majority of their lives on the wing. They exhibit remarkable agility in flight, capturing insects in their bills for sustenance. Even drinking is performed in flight, a testament to their aerial proficiency.
The Indian swiftlet's diet consists primarily of insects, which they adeptly catch mid-air with their bills.
The male Indian swiftlet is responsible for constructing the nest, a half-cup structure built on vertical surfaces, often within the shelter of a cave. The nest is crafted using the male's thick saliva, resulting in a white, shiny abode. Into this nest, the swiftlet typically lays two eggs.
The Indian swiftlet is currently classified as Least Concern on the IUCN Red List, indicating that, at present, there are no immediate threats to its population numbers.