Gray-rumped Treeswift Hemiprocne longipennis Scientific name definitions

21–25 cm; 42·8 g (one harterti). Dark forehead-crest. Male has ear-coverts rufous, rest of face black, with no white striping; greenish grey from lower mantle towards rump, rump pale grey, rest of upperparts glossy blue- to green-shot black; underwing-coverts black with glossy green fringing; underparts uniformly pale greenish-grey, with belly and undertail-coverts contrastingly whitish. Averages larger than H. coronata but shorter-tailed, streamers not projecting past folded wingtips, and has less rufous on face, while also note more contrast in both upperparts (with rump) and underparts (1 Chantler, P., and G. Driessens (2000). Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. Pica Press, Robertsbridge, UK. Close ). Widely sympatric H. comata obviously darker and smaller than present species, and also has white facial stripes and bronzy upperparts (1 Chantler, P., and G. Driessens (2000). Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. Pica Press, Robertsbridge, UK. Close ). Female as male, but with ear-coverts deep bottle-green. Juvenile has head and body more or less as in H. coronata, but dorsal patterning often more complex, particularly on cap, which lacks contrasting lateral band, and has no obvious pale loral spot; first-winter has adult-type body feathers, but retained juvenile wing and tail feathers (1 Chantler, P., and G. Driessens (2000). Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. Pica Press, Robertsbridge, UK. Close ). Races harterti and perlonga shade darker than nominate on anterior underparts (some overlap between harterti and nominate in this feature) (1 Chantler, P., and G. Driessens (2000). Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. Pica Press, Robertsbridge, UK. Close ), and rump less pale in relatively large perlonga (wing of male 175–178 mm, vs. 154–169 mm in harterti) (1 Chantler, P., and G. Driessens (2000). Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. Pica Press, Robertsbridge, UK. Close ); <em>wallacii</em> largest (wing of male 179–183 mm, vs. male of nominate 167–168 mm) (1 Chantler, P., and G. Driessens (2000). Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. Pica Press, Robertsbridge, UK. Close ), with plumage much as nominate.

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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.

Groves of large trees and edge and canopy breaks of more continuous semi-evergreen and evergreen forest inland, locally tall mangroves and coastal casuarinas, also making use of tall plantation (e.g. mature rubber) (2 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ) and mature parkland trees. Everywhere selects well-exposed, bare perches at outer edge of the high canopy. From plains level to 1200 m in Malay Peninsula, to 1400 m on Sulawesi (1 Chantler, P., and G. Driessens (2000). Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. Pica Press, Robertsbridge, UK. Close ), 1500 m on Borneo (3 Mann, C. F. (2008). The Birds of Borneo: An Annotated Checklist. B.O.U. Checklist 23. British Ornithologists’ Union, and British Ornithologists’ Club, Peterborough. Close ) and 1550 m in Java.

Breeds over its whole altitudinal range, with probably no more than post-breeding local dispersive movements; vagrants or rare residents recorded in Philippines on Sibutu (Nov 1971) and Tawitawi (Aug 1994) (4 Brooks, T., and G. Dutson (1997). Twenty-nine new island records of birds from the Philippines. Bulletin of the British Ornithologists’ Club 117(1):32–37. Close ).

Flying arthropods; prey selection hardly known, but regularly attends swarms of alate termites and, in Borneo, recorded taking bees from the edge of a flying swarm. Prey caught during long (300–400 m) (2 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ) sorties out from a favoured tree crown , typically well clear of vegetation surfaces. Regularly uses same perches year after year (2 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ). In Selangor, Malaysia, mean foraging height above open ground was 35 m, and above forest canopy was 47 m. Like other Apodiformes, drinks by scooping water in a fast, skimming swoop down to an open surface. Especially active at dusk and immediately following rain (2 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ), when sometimes consorts with other aerial feeders, and forms flocks of its own species of up to 70 (5 Duckworth, J. W., R. J. Wilkinson, R. J. Tizard, R. N. Kelsh, S. A. Irvin, M. I. Evans, and T. D. Orrell (1996). Bird records from Similajau National Park, Sarawak. Forktail 12:159–196. Close ).

Gives shrill wader- or tern-like calls both on perch and in flight (sometimes most excitedly, even hysterical-sounding, when coming into land), with considerable variation reported, the commonest being a harsh, piercing “ki”, sometimes given in series, “ki-ki-ki-kew”; gives disyllabic “too-eit” or “whit-kep”, the second note sounding slightly higher and metallic, somewhat like H. coronata (1 Chantler, P., and G. Driessens (2000). Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. Pica Press, Robertsbridge, UK. Close ).

In N Hemisphere, laying season overall Feb–Aug/Sept (chick records in Oct in Peninsular Malaysia) (1 Chantler, P., and G. Driessens (2000). Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. Pica Press, Robertsbridge, UK. Close ), peaking in Mar–Jun, but also eggs in mid-Dec on Borneo (1 Chantler, P., and G. Driessens (2000). Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. Pica Press, Robertsbridge, UK. Close ); in S (Java and Sulawesi) (1 Chantler, P., and G. Driessens (2000). Swifts: A Guide to the Swifts and Treeswifts of the World. 2nd edition. Pica Press, Robertsbridge, UK. Close ) active nests Dec–Aug. Double-brooded in Kalimantan Barat (Borneo), Apr–May and Aug–Sept (3 Mann, C. F. (2008). The Birds of Borneo: An Annotated Checklist. B.O.U. Checklist 23. British Ornithologists’ Union, and British Ornithologists’ Club, Peterborough. Close ). Nesting dispersed but, as with H. coronata, often with several other pairs in the neighbourhood. Copulates on perch (6 Bishop, K. D. (1992). New and interesting records of birds in Wallacea. Kukila 6(1):8–34. Close ). Nest as that of H. coronata, built by both sexes, typically a half-saucer of hardened saliva incorporating small scraps of moss, bark flakes and body feathers, c. 36 × 24 mm, maximum outside depth 12 mm, built out as a bracket 5–30 m up on a thin, exposed branch. Lays one white egg, size 25·6 mm × 17·4 mm (2 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ); both pair-members incubate and both tend the chick; incubation and fledging periods not precisely recorded, but is at least 50 days (2 Wells, D. R. (1999). The Birds of the Thai-Malay Peninsula. Volume 1. Non-passerines. Academic Press, London, UK. Close ); chick down is grey.

Not globally threatened (Least Concern). More or less common through most of its range, and under no serious threat overall. As with H. coronata, preference for patchy tree cover and edge habitat over continuous natural forest suggests that it may in fact have benefited from some forest disturbance; the species is absent, however, from still rapidly expanding oil palm agriculture, and populations in the plantation landscape would benefit from a commitment to the maintaining of natural or semi-natural shelterbelts. The opposite trend is set in Malaysia, where over-use of organophosphate pesticide sprays in suburban parkland habitat is another rising issue. Pesticides are suspected to be behind a recent population decline in Singapore. Elsewhere, the general impression is that bird-hunting, exacerbated by expanding availability of airguns, will have damaged non-forest populations through much of W Indonesia; hunting has caused quite severe reduction of nominate race, along with nearly all bird species, in lowland Java.