Description Himalayan swiftlet

himalayan swiftlet - thailand

this 13–14 cm long swiftlet has swept-back wings resemble crescent or boomerang. body slender, , tail forked. is, in many respects, typical swift, having narrow wings fast flight, , wide gape , small beak surrounded bristles catching insects in flight. legs short, preventing bird perching, allowing cling vertical surfaces.

it grey-brown above , paler brown below. has pale grey rump , pale patch above , behind bill. sexes similar, juvenile has less distinct rump.

there 5 subspecies, differing in rump tone.

a. b. brevirostris breeds in himalayas east bangladesh, myanmar , thailand. this, nominate race, altitudinal migrant, breeding above 4,500 m, wintering between 900 , 2750 m altitude.
a. b. innominata breeds in central china, , winters in southwestern thailand , malay peninsula. rump darker grey nominate brevirostris
a. b. inopina breeds in southwestern china. darkest-rumped race.
a. b. rogersi indochinese swiftlet, breeds in eastern myanmar, western thailand , laos. small, pale-rumped race.
a. b. vulcanorum volcano swiftlet, breeds in java, indonesia on volcanic peaks. has dark underparts , indistinct pale grey rump.

over of range, swift, in south of breeding area , of wintering range can difficult distinguish species other collocalia swiftlets.