Grey-rumped Treeswift

Identification

The grey-rumped treeswift is a small, distinctive bird with several key field marks. Adult males are particularly striking, featuring a dark grey throat and chest that contrasts sharply with a white belly. Both sexes display a greenish sheen on their upper parts, and males are further distinguished by dull orange-red or chestnut-colored ear coverts—a feature absent in females. When perched, a characteristic shared with all treeswifts, the wing tips cross over the tail, creating a compact silhouette quite different from the appearance of true swifts.

Range & Habitat

This species has an extremely large range across Southeast Asia, found in Brunei, Indonesia, Malaysia, Myanmar, the Philippines, Singapore, and Thailand. It is commonly found in peninsular Malaysia. The grey-rumped treeswift shows a preference for forested and wetland habitats, occurring in subtropical or tropical moist lowland forests, mangrove forests, and moist montane forests.

Behaviour & Diet

Unlike true swifts, grey-rumped treeswifts are arboreal birds, typically seen perched on trees, high-tension power transmission lines, and pylons rather than in continuous flight. They are insectivorous, occasionally catching prey in flight by sallying—making short hunting flights—from their perches. Their most remarkable adaptation is their extraordinary nest construction: they build tiny, half-saucer-shaped nests made from hardened saliva interspersed with feathers, mosses, and flakes of tree bark, attached to tree branches. The fragility of this nest structure is extraordinary; it is attached to the branch on only one side, so the incubating parent does not sit directly on it. Instead, the bird perches on the branch above the nest and fluffs out its breast feathers to cover and incubate the single egg, which is held in place by saliva. Both sexes participate in incubation duties, and during shifts of parental care, the arriving partner carefully slides over the nest to take over brooding responsibilities.

Best Time & Places to See It

Peninsular Malaysia offers reliable opportunities to encounter grey-rumped treeswifts, where they are commonly found. Suitable habitat throughout their range—particularly in lowland and montane forests, as well as mangrove areas—should yield sightings. However, specific information about population trends and seasonal movements is limited, so local guides familiar with current distribution patterns in your chosen destination will be invaluable.

Photography Tips

Photographing grey-rumped treeswifts requires patience and attention to their perching behavior. Since they are arboreal and spend considerable time stationary on perches, including power lines and pylons, these perches offer excellent opportunities for detailed photography of plumage and field marks. The contrast between the males' dark grey chest and white belly, along with the chestnut ear coverts, provides striking compositional elements. Position yourself to capture the characteristic crossed wing tips over the tail when they are perched, as this is a defining feature of the species. Early morning and late afternoon light will best reveal the greenish sheen of their upper parts.