Himalayan Swiftlet Aerodramus brevirostris Scientific name definitions

13–14 cm; 12·5–13 g. Large swiftlet  with obviously forked tail; grey rump band clearly paler than dark brown upperparts ; underparts very uniform pale grey; lightly feathered tarsi and white rami. Juvenile of all races has more concealed white in contour feathers, a less well-defined rump band and more sparsely feathered tarsi. Race innominatus has darker rump than nominate; rogersi smallest race, similar to nominate but lacking white rami and tarsus feathering. Capable of echolocation, at least race innominatus.

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Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Primarily in highlands, particularly over wooded river valleys , though not uncommon over wide range of habitats, including cultivated areas. Recorded to 4575 m in Nepal and at 600–3000 m in Bhutan (exceptionally 3800 m).

Partial migrant, with apparently only relatively small proportions of poulations moving S for winter. Recorded Nov–Mar in Malay Peninsula. Nocturnal migrants recorded in Nov at Fraser’s Hill, W Malaysia, were nominate race or innominatus. In Strait of Malacca, four birds on passage through Riau Archipelago in mid-Sept, and three individuals of indeterminate race collected in Nov from lighthouse; believed to be common passage migrant on Karimun Besar. Status in Sumatra uncertain, where in past reported to be a breeding resident, but may be merely winter visitor or straggler; large southward movement of c. 2860 swiftlets over S Serkap in early Oct probably refers to this species. Nominate race is altitudinal migrant in parts of Himalayas, wintering at 900–2750 m in Nepal (exceptionally even lower during bad weather), and generally moving to areas below 1800 m (reaching down to 200 m) in Bhutan between Nov and mid Mar; a rare winter visitor to N & E Bangladesh (Oct–Mar), where first recorded in 1985 and rarely observed in small flocks. Type specimen of race innominatus from S Andamans, where species is probably only rare straggler in winter (reports of breeding on Narcondam rejected) and status difficult to establish due to similarity to smaller A. fuciphagus. Sight records from Maldives not reliably distinguished from A. unicolor. Race rogersi not known with certainty S of Surat Thani; has been recorded in SW Yunnan (SC China). One remarkable, photo-documented, record from Socotra, off Horn of Africa, in Nov 2007 (following a cyclone in W Indian Ocean), but full details never published (1 Demey, R. (2008). Recent reports. Bulletin of the African Bird Club 15(1):126–139. Close ), with a record, without documentation, on Hainan, SE China, in Dec 2005 (2 Lu, G., Li, F., Lee, K.S., Chan, B.P.L. and Sung, Y.H. (2015). New avifaunal records for Hainan Island, China 2003–2013. BirdingASIA. 23: 122–123. Close ).

Diptera and Hymenoptera recorded. Gregarious , typically up to 50; larger flocks, e.g. 300–500, not uncommon. Associates with other swifts and hirundines. Often descends from hills in evenings or during poor weather to forage over cultivated land, particularly paddies, where areas of standing water especially favoured.

Calls include a dry repeated “chit..chit..” and a drawn-out reeling rattle. In display-flight gives an extremely rapid, buzzy, musical twittering in short bursts that run up and down in pitch, with more vehemently buzzy and more clearly enunciated single notes, e.g. “zheek, zheek, zheek ...”, mixed with clicking notes and squeaky twittering. Race innominatus echolocates, producing short bursts of very short, dry, crackling clicks, which speed up and then slow down.

Season Apr–Jun, India; eggs collected late Apr, Shan States, Myanmar. Colonial. Nests on vertical rock-faces, inside caves or similar structures, with the individual nests often in contact ; self-supporting bracket-shaped nest of vegetable materials agglutinated with sparse, but firm, saliva; cup diameter c. 6 cm, inside depth 2 cm and slightly tapering pedestal below, 5 cm thick. Copulation noted at nest and in air; clutch two white eggs, mean size 21·8 mm × 14·6 mm. No further information.

Not globally threatened (Least Concern). Common throughout most of breeding range, though is an uncommon wintering species in Malay Peninsula; rather rare in China; recorded as a rare winter visitor in New Forest, Dehra Dun, N India; in suitable habitat, for instance in N Thailand, species can be abundant, and is especially obvious around dusk; first records for W Myanmar as recently as 1994. One colony in Bhutan thought to number at least 1000 birds.