The Crested Treeswift (Hemiprocne coronata) is the only species of bird that belongs to the family Hemiprocnidae. It is a medium-sized bird with a slender, streamlined body and long, narrow wings. It is primarily found in tropical and subtropical regions of Southeast Asia, including Vietnam.
The Crested Treeswift is a forest-dwelling bird that feeds on insects, which it catches on the wing. It has a distinctive crest of feathers on its head, which gives it its common name. This species of bird is known for its fast, acrobatic flight and its ability to glide for long distances. The Crested Treeswift is an important species in the ecosystem, helping to control the populations of insects and other small invertebrates.
The crested treeswift is a common resident breeder from the Indian subcontinent. It is found in India, Sri Lanka, Bhutan, Bangladesh, Nepal, Myanmar, Thailand, Vietnam, Cambodia, Laos, and China. These are birds of open woodland and deciduous forests. They are also found in open areas near trees and in parks and gardens. Most birds live in the lowlands below 1000 m.
The crested treeswift builds a tiny and thin-walled and shallow nest made up of pieces of bark and feathers which is glued with saliva to the side of an exposed tree branch. It lays one blue-grey egg which is incubated by both sexes. The nest is so small that incubating birds may just appear as if just normally perched on a branch having a knot.
Adults may also sit along the branch when incubating. Nearly half the egg is visible above the edge of the nest and is covered by the down feathers of the breast and belly when incubating. The breeding season is during the hottest part of summer from March to July and nests may be positioned on the eastern side of a branch so that the adult would have the sun on its back during the afternoon.
Females were observed to incubate more while males sat nearby or captured insects. The nestlings are cryptically patterned in grey and freeze when threatened with the head held low and beak held slightly upward and appear like a knot on a tree branch or when sitting horizontally appear like a chameleon
A Tip to Identify Crested Treeswift in the Field
A medium-sized swift-like bird with long tail-streamers. Adult has a dark greenish-blue crest visible while it perches, mostly on trees. It has uniform pale gray upper parts, black lores with a fine white border above, and much rufous on the face of the male.
Underwing feathers, breasts, and flanks are pale gray, and the belly is whitish. The female has a dark mask, replacing the male’s rufous coloration. The species is partial to lightly wooded country, avoiding open plains and wet forests. Mostly seen on the wing, and at times perched, making a characteristic “gek-kuk” call.