Passeriformes / Hirundinidae / Delichon
Asian House Martin
Delichon dasypus · 烟腹毛脚燕
Introduction
A migratory passerine of the swallow family Hirundinidae, breeding in the Himalayas and central and eastern Asia, with wintering grounds in Southeast Asia or lower mountain elevations. It breeds in colonies, building mud nests under overhangs on cliffs or buildings, and feeds primarily on small insects caught in flight. The species is locally abundant, expanding northward in Siberia, and assessed as Least Concern by the IUCN.
Description
Adults of the nominate subspecies are 12 cm (4.7 in) long, with dark steel blue upperparts, a contrasting white rump, and grey-washed white underparts. The tail is slightly forked, brownish-black on top, with grey-brown underwings. Legs and feet are brownish-pink and covered with white feathers; eyes are brown, and the bill is black. Males are somewhat whiter below than females, especially in fresh plumage. Juveniles are less glossy, with dark brown upperparts, sometimes a brownish rump wash, and grey-white underparts. Subspecies D. d. cashmeriensis has brighter blue upperparts and a whiter rump, while D. d. nigrimentalis is the smallest race.
Identification
Distinguished from the Nepal house martin by the latter's black chin, black undertail coverts, and squarer tail. Compared to the common house martin, it is darker underneath and has a less deeply forked tail. Confusion may occur with the eastern race of the common house martin, which has a more pronounced tail fork. Vocalizations include a rippling metallic trill or sibilant twitter for song, and a dry metallic cheep, often with two or three syllables, which is more rasping than that of the common house martin.
Distribution & Habitat
Three subspecies exist. D. d. dasypus breeds in southeast Russia, Kuril Islands, Japan, and sometimes Korea, migrating through eastern China to winter in the Malay Peninsula, Borneo, Philippines, Java, and Sumatra. D. d. cashmeriensis breeds in the Himalayas (Afghanistan to Sikkim), Tibet, and western/central China at 1,500–5,000 m altitude, wintering at lower foothills, northeastern India, Bangladesh, Myanmar, and northern Thailand. D. d. nigrimentalis breeds in southeastern China and southern Siberia; its wintering grounds are largely unknown, though birds in Taiwan move to lower altitudes. Non-breeding individuals have been recorded in the United Arab Emirates. Habitat includes mountainous valleys, gorges, coastal cliffs, and large man-made structures.
Behavior & Ecology
Breeds in colonies under overhangs on vertical cliffs or buildings. Nests are deep mud cones lined with grasses or feathers, often left open rather than fully enclosed. Clutch size is typically three or four plain white eggs (occasionally up to six), averaging 20.2 mm × 14.1 mm and weighing 2.1 g. Both sexes build the nest, incubate, and feed chicks. Feeds on insects taken in flight, mostly small flies, aphids, and Hymenoptera, but also picks terrestrial springtails and Lepidoptera larvae from the ground. Hosts parasites including the house martin flea and avian malaria; predators likely include fast-flying falcons like the Oriental hobby.
Conservation
Evaluated as Least Concern by the IUCN. The species has a large range exceeding 20,000 square kilometers, with more than 10,000 mature individuals. Numbers appear stable, and the range is not contracting; it is locally abundant and expanding northwards in southern Siberia.
Source: Wikipedia · CC BY-SA 3.0
Taxonomy
- Order
- Passeriformes
- Family
- Hirundinidae
- Genus
- Delichon
Vocalizations
Subspecies (3)
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Delichon dasypus cashmeriense
Himalayas (southeastern Afghanistan to India and western China)
Data Sources
Species description from Wikipedia, licensed under CC BY-SA 3.0.
Bird images and sounds sourced from GBIF, contributed by citizen scientists worldwide under Creative Commons licenses.
Taxonomy data from AviList 2025.
