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Delichon

Delichon is a small genus of passerine birds in the swallow family Hirundinidae, consisting of four species collectively known as house martins.^[1] These compact birds measure 12–14 cm in length, weigh 10–23 g, and have wingspans of 26–29 cm, featuring glossy blue-black upperparts, prominent white rumps, and slightly forked tails.^[1] The species within Delichon include the Western House-Martin (D. urbicum), Siberian House-Martin (D. lagopodum), Asian House-Martin (D. dasypus), and Nepal House-Martin (D. nipalense), recently recognized as distinct from former subspecies. They are primarily distributed across Eurasia, with breeding ranges extending from Europe and northern Africa through central and eastern Asia to the Himalayas; some populations migrate to sub-Saharan Africa and southwestern Asia for wintering.^[1] These birds exhibit subtle plumage variations, such as differences in the extent of the blue cap and tail fork depth, which aid in species identification.^[1] House martins are aerial insectivores that forage on flying insects in open habitats near human settlements, often building gourd-shaped mud nests under eaves or cliffs in colonies.^[1] They are socially monogamous, though extra-pair copulations occur, and use a repertoire of chirping calls and short songs for communication, territory defense, and mate attraction.^[1] All species are classified as Least Concern by the IUCN, though populations of some, particularly in Europe, have declined due to habitat alterations, severe weather, and reduced insect prey from pesticides and climate change.^[2]^[3]

Taxonomy and evolution

Etymology and classification

The genus Delichon was introduced in 1854 by American naturalist Thomas Horsfield and British entomologist Frederic Moore to describe the Nepal house martin (Delichon nipalense), distinguishing it from other swallows based on its feathered tarsi and nest-building habits. The name Delichon is derived from New Latin, formed as an anagram of Chelidon, the former genus encompassing many swallows and martins, itself from the Ancient Greek chelīdōn (χελιδών), meaning "swallow."^[4] This etymology reflects the group's close affinity to typical swallows while highlighting their specialized adaptations, such as mud nests often built on cliffs or buildings. Within the family Hirundinidae (swallows and martins), Delichon is placed in the subfamily Hirundininae, which includes most non-river martin species and is characterized by aerial insectivory and varied nesting strategies. The genus is phylogenetically close to Hirundo, from which it diverged relatively recently, with molecular studies indicating Delichon as monophyletic and nested within a broader clade of mud-nesting swallows; occasional hybridization occurs between Delichon urbicum and Hirundo rustica.^[5] A significant taxonomic revision occurred in 2021, when the Siberian house martin (Delichon lagopodum) was split from the Western house martin (Delichon urbicum) based on differences in plumage (e.g., broader white rump patch), morphometrics (shallower tail fork), vocalizations, and genetic data from ultra-conserved elements, with no evidence of interbreeding in sympatric zones. This split was confirmed in 2023 by the eBird/Clements Checklist, which now recognizes four extant species in the genus: the Western, Siberian, Asian (Delichon dasypus), and Nepal house martins (detailed in the following section).^[6]

Species

The genus Delichon includes four extant species of house martins, small swallows adapted to temperate and montane environments across Eurasia. These species were historically lumped or debated, but recent taxonomic revisions based on morphological, vocal, and molecular evidence have affirmed their separation, with the Siberian house martin recognized as distinct from the Western house martin in 2021.^[7] The Western house martin (Delichon urbicum) breeds throughout much of Europe, North Africa, and western Asia, extending east to western Siberia and the Tien Shan mountains. It is strongly migratory, with populations wintering primarily in sub-Saharan Africa and, to a lesser extent, South Asia from September to April. Adults measure 13–14 cm in length, with an average weight of 18 g, wingspan of 26–29 cm, and a deep tail fork of 1.5–2 cm. It is characterized by glossy steel-blue upperparts, a sharply defined white rump patch, pure white underparts, and brownish-black flight feathers.^[1] The Siberian house martin (Delichon lagopodum) breeds in eastern Asia, ranging from the Altai Mountains and Mongolia eastward through Siberia, the Russian Far East, and northeastern China to the Sea of Okhotsk. It migrates southward to Southeast Asia, including Myanmar, Thailand, and southern China, from September to May. Similar in size to D. urbicum at 13–14 cm long, it averages around 18 g and features an extended white rump patch that reaches higher onto the lower back, a shallower tail fork of about 1 cm, and brighter, cleaner white underparts with less grey wash. Its contact calls are lower-pitched, flatter, and more element-rich than those of the Western house martin.^[8] The Asian house martin (Delichon dasypus) breeds across central and eastern Asia, from the Himalayas and southern China northward to Russia, Mongolia, Korea, and Japan, with subspecies varying in distribution. Most populations are migratory, wintering in Southeast Asia, southern Japan, and the Greater Sundas from October to April, though some southern forms are partially resident. Measuring 12–13 cm in length and weighing about 18 g, it exhibits darker, less glossy blue-black upperparts than its congeners, with grey-brown underparts, a narrower white rump, and a moderately forked tail.^[9] The Nepal house martin (Delichon nipalense), the smallest member of the genus, is primarily resident in the Himalayan region, breeding from Uttarakhand and the Tibetan Plateau eastward through Nepal, Bhutan, and Myanmar to southern China, northern Laos, and northwestern Vietnam, with some altitudinal movements to lower elevations post-breeding. It reaches 11.5–12.5 cm in length and 14–16 g in weight. Plumage includes glossy blue upperparts, but it is distinguished by more extensive blue-black on the head sides, a black upper throat and undertail coverts, and a square (unforked) tail, contrasting with the forked tails of other species. Its flight calls are high-pitched "chi-i" notes.^[10] Identification among Delichon species relies on subtle differences in rump patch extent (broader and higher in D. lagopodum), plumage gloss and tone (glossier in D. urbicum and D. nipalense, duller in D. dasypus), tail shape (square in D. nipalense), and vocalizations (e.g., lower-pitched calls in D. lagopodum versus higher in D. nipalense).^[7]

Fossil record

The earliest known fossils attributed to the genus Delichon date to the late Miocene (MN 13, approximately 11–5 million years ago) from Polgárdi in Fejér County, western Hungary. Delichon polgardiensis, described from coracoid and ulna fragments, represents a medium-sized swallow with a strongly protruding acrocoracoid on the coracoid and a rounded, claw-shaped condylus dorsalis on the ulna, features that align with but differ slightly in proportions from extant species.^[11] These remains indicate an early diversification of Delichon within Europe during the Neogene. Fossils from the Pliocene (MN 15–16, approximately 5–3 million years ago) further document the genus in the Carpathian Basin, also in Hungary. Delichon pusillus from Csarnóta 2 in Baranya County is a smaller form than modern Delichon species, based on carpometacarpus bones that closely match contemporary morphology in overall structure. Similarly, Delichon major from Beremend 26 exhibits larger dimensions while sharing key skeletal characteristics, such as those in the coracoid, suggesting variability in body size possibly linked to adaptations for foraging in open habitats.^[11] The known fossil record of Delichon points to an origin and initial radiation in Eurasia, with all described species confined to European localities and displaying skeletal traits consistent with aerial insectivory—a hallmark of the Hirundinidae family—that predate the extant species. No fossils of the genus have been reported outside Europe, highlighting a potential Eurocentric early history despite the modern Palearctic distribution. The scarcity of Asian Delichon fossils may reflect gaps in preservation, particularly in the open or montane breeding environments typical of the genus.^[11]

Physical description

Morphology

Species in the genus Delichon are small passerines with body lengths of 12–14 cm, wingspans of 26–29 cm, and weights generally ranging from 10–23 g.^[1]^[9]^[10] The tails are short and forked, with a shallow fork relative to other swallow genera. The Nepal house martin (Delichon nipalense) represents the smallest species in the genus.^[10] Characteristic adaptations of Delichon include feathered tarsi and toes, a trait unique to this genus and linked to their habit of constructing mud nests.^[1]^[9]^[10] They feature broad bills suited to aerial insect capture and robust, pointed wings that enable extended flight durations.^[1]^[12] Sexual dimorphism is minimal across Delichon species, with sexes exhibiting similar overall body sizes.^[13] Juveniles differ from adults primarily in having shorter wings and tails.^[1]^[9]

Plumage and vocalizations

Species of the genus Delichon exhibit distinctive plumage characterized by glossy blue-black upperparts, a prominent white rump, and white underparts, with a shallowly forked tail featuring white tips on the outer feathers.^[1] This coloration provides stark contrast during flight, aiding in species identification. The Nepal house martin (D. nipalense), however, deviates with sooty brown upperparts lacking the typical blue gloss, while retaining the white rump and underparts.^[14] Juveniles across the genus are generally duller, with browner tones and reduced gloss on the upperparts, and non-breeding adults show seasonal wear where white areas become mottled with brown-gray.^[1] The Siberian house martin (D. lagopodum) stands out with a larger white rump patch that extends farther up the back and onto the lower back, contrasting more sharply with its steel blue-black upperparts.^[8] Vocalizations in Delichon species are structurally similar, consisting primarily of twittering calls delivered in flight and soft songs produced near the nest.^[8] The typical contact call is a rolling, buzzy "prrrt" or "prit-prit," often repeated in series, functioning in territory defense and flock coordination.^[1] Songs are rapid twittering phrases lasting several seconds, incorporating gurgling, squeaky, or buzzing notes.^[8] Species differences are subtle but include pitch and duration variations; for instance, the contact call of the Siberian house martin (D. lagopodum) is lower-pitched and longer than that of the Western house martin (D. urbicum), while the Nepal house martin produces a high-pitched "chi-i" in flight.^[8]^[10] The Asian house martin (D. dasypus) has calls with a more rasping quality and a rippling metallic trill in its song.^[15]

Distribution and habitat

Geographic range

The genus Delichon is confined to the Old World, encompassing Eurasia and North Africa, with all species breeding exclusively in the Northern Hemisphere and no established populations in the Americas or Australia.^[1]^[8] The western house martin (Delichon urbicum) has the broadest breeding range within the genus, extending across Europe, North Africa (including the Atlas Mountains), and west-central Asia eastward to western Siberia, central Mongolia, northern Kazakhstan, and the Tien Shan and Kashmir regions.^[1] Populations from western and central Europe (D. u. urbicum) migrate southward to winter primarily in sub-Saharan Africa, favoring tropical savannas and wetlands, while southern populations (D. u. meridionale) winter in Africa and southwest Asia, including India and Sri Lanka.^[1] The Siberian house martin (Delichon lagopodum) breeds in eastern Asia, from the middle and upper Yenisey River, Altai Mountains, and Mongolia eastward to Anadyrland, the Sea of Okhotsk, and northeastern China, often in open valleys, rocky hillsides, or human settlements at various elevations.^[8] It is a long-distance migrant, wintering in southern and southeastern Asia, including much of Myanmar, northern Thailand, Laos, Cambodia, parts of Vietnam, and possibly southern China and northern India.^[8] The Asian house martin (Delichon dasypus) breeds in central and eastern Asia, with the nominate subspecies (D. d. dasypus) occurring from southeastern Russia (Khamar-Daban and Ussuriland), northern Mongolia, the Kuril Islands, northeastern and eastern China, Korea, and Japan; the subspecies D. d. cashmeriense in the Himalayas from northern Pakistan to southern-central China; and D. d. nigrimentale in southern and eastern China and Taiwan.^[9] Breeding occurs at elevations from 1300 m to over 4800 m in India and up to 4000 m in Nepal, with wintering grounds in lower elevations of northern and eastern India, Bangladesh, southern Myanmar, northern Thailand, Laos, Vietnam, Peninsular Malaysia, the Greater Sundas, and the Philippines, though some populations in southern China remain partially resident.^[9] The Nepal house martin (Delichon nipalense) is the most range-restricted species, breeding in the Himalayan region from Uttarakhand and Himachal Pradesh in northern India, through Nepal, Bhutan, and the adjacent Tibetan Plateau, eastward to northeastern India (Arunachal Pradesh), southern China (Yunnan and southern Tibet), northern Myanmar, northern Thailand, northern Laos, and northwest Vietnam (western Tonkin), with the subspecies D. n. cuttingi in the eastern portion of this range.^[10] It is largely non-migratory and resident, undertaking only short-distance altitudinal movements to lower elevations (down to 150–300 m) during the non-breeding season, primarily in valleys, mountain ridges, and near cliffs or villages at 1000–4000 m.^[10] Range overlaps occur in central Asia, where the western house martin is sympatric with the Asian house martin south of Lake Baikal and with the Siberian house martin in regions like Buryatia and Mongolia, though the latter two show elevational segregation with the Asian house martin favoring higher altitudes; distributions are generally parapatric without evidence of hybridization.^[1]^[8]^[9] Vagrants of eastern Delichon species, such as the Siberian and Asian house martins, are rare in western Europe, with records limited to occasional individuals potentially overshooting migration routes westward to Kazakhstan or the Western Palearctic.^[8]^[9]

Habitat preferences

Delichon species, collectively known as house martins, generally favor open landscapes proximate to water bodies, which provide essential mud for nest construction and abundant flying insects for sustenance. These birds avoid dense forests, preferring instead expansive areas such as grasslands, farmlands, and wetlands that support high insect densities. Nesting occurs on vertical substrates including natural cliffs, caves, and human-made structures like building eaves or bridges, reflecting their adaptability to varied topographies from lowlands to montane regions up to 4,000 meters.^[1]^[16] In their breeding habitats, European populations of the Western House-Martin (Delichon urbicum) thrive in both urban and rural settings, often selecting sites with older architecture that offers sheltered ledges under roofs, alongside proximity to open fields and mud sources. Across Asia, the Asian house martin (D. dasypus) and Nepal house martin (D. nipalense) exhibit preferences for mountainous terrains, including river valleys, gorges, and rocky ridges, where they nest in natural crevices or on cliffs at elevations typically between 800 and 3,000 meters. The Siberian house martin (D. lagopodum), breeding in eastern Asian steppes and taiga edges, similarly utilizes semi-open habitats near water, incorporating both natural rock faces and anthropogenic sites.^[17]^[18]^[19] For foraging, Delichon species exploit lowland fields, marshes, and coastal zones rich in aerial insects, frequently ranging over wetlands and cultivated lands while shunning heavily wooded areas that limit prey accessibility. This habitat selectivity underscores their reliance on unobstructed airspace for efficient hunting.^[1]^[20] These martins demonstrate notable tolerance for human-modified environments, readily colonizing towns and agricultural zones, yet they prioritize insect-abundant locales to sustain breeding success, with studies indicating higher occupancy in landscapes balancing open space and structural nesting opportunities.^[21]

Behavior and ecology

Breeding biology

Delichon species are colonial breeders, typically forming groups of 10–100 pairs at nesting sites, with laying dates often synchronized within colonies to facilitate communal defense and foraging efficiency. Nests are constructed collaboratively by both parents on vertical surfaces such as building eaves, cliffs, or overhangs, often in urban or rural settings near suitable habitats.^[2]^[10]^[22] The nests consist of enclosed mud cups, formed from thousands of small pellets collected from nearby sources, and lined with grasses, vegetable fibers, moss, or feathers for insulation and comfort; construction generally requires 2–4 weeks, though pairs may reuse or repair old nests in subsequent seasons to reduce effort. In the Northern House Martin (D. urbicum), nests are attached to artificial structures like houses or bridges, while the Asian House Martin (D. dasypus) favors subalpine building interiors, and the Nepal House Martin (D. nipalense) prefers cliff faces, occasionally using human sites. Colony sizes can exceed 600 pairs in exceptional cases, such as the largest known D. dasypus site in China's Wuyishan Nature Reserve.^[2]^[22]^[10] Clutches comprise 2–5 eggs, averaging 3–4, which are white or pinkish-white with fine spots; laying occurs from March to July depending on latitude and elevation, with first broods larger than subsequent ones. Both parents share incubation duties, lasting 14–16 days until hatching, after which the altricial chicks remain in the nest for 22–32 days before fledging. Pairs often raise multiple broods per season, up to three in favorable conditions, with 38–48% attempting a second brood and replacement clutches common if early attempts fail.^[2]^[23]^[22]^[10]

Diet and foraging

Species of the genus Delichon are obligate aerial insectivores, relying almost exclusively on small flying insects captured during flight. Their diet consists primarily of Diptera (flies), which can comprise up to 60% of the food items in some populations, followed by Homoptera (aphids) at around 18%, parasitic Hymenoptera at 11%, and Coleoptera (beetles) at 5%. Other components include Odonata (dragonflies), Lepidoptera (moths and butterflies), Orthoptera (grasshoppers and crickets), and occasionally spiders or small fruits such as elderberries (Sambucus nigra). Regional variations occur; for instance, in Switzerland, Diptera account for 45% and aphids for 33%, while in Poland and Russia, Hemiptera (including aphids) dominate at 58% and 53%, respectively.^[1]^[9] Foraging typically occurs in flocks, often mixed with other aerial insectivores like swifts or other swallows, over open habitats such as fields, meadows, and water bodies. Flight during foraging is relatively slow and at considerable heights, averaging 21 m during the breeding season and exceeding 50 m in winter, with individuals traveling up to 2 km from the nest but usually foraging within 0.45 km on average. They occasionally perch to capture insects or follow agricultural activities like plowing to exploit disturbed prey. Nestlings are provisioned with compacted boluses of insects delivered by both parents, with feeding rates highest in early summer (May) and declining toward late summer (August). Dietary composition shifts seasonally, with aphids forming a higher proportion (up to 46%) early in the breeding season (May) and dropping to as low as 4% by late summer (August–September) in southern England populations.^[1]^[1]^[24] Delichon species obtain water while in flight by skimming low over the surface of ponds, rivers, or lakes, dipping their bills to scoop up liquid without perching. This behavior also facilitates occasional bathing to maintain plumage. Similar foraging strategies and diets are reported across the genus, including for the Asian house martin (D. dasypus), which consumes small Diptera (especially Nematocera and Brachycera), Hemiptera, Coleoptera, and Hymenoptera, and the Nepal house martin (D. nipalense), which feeds mainly on Diptera in mixed flocks often at high altitudes.^[25]^[9]^[10]

Migration patterns

The three migratory species in the genus Delichon—the northern house martin (D. urbicum), Asian house martin (D. dasypus), and Siberian house martin (D. lagopodum)—undertake long-distance southward journeys of 5,000–10,000 km to reach their wintering grounds, depending on breeding latitude and specific routes.^[1]^[9]^[8] In contrast, the Nepal house martin (D. nipalense) is largely sedentary and resident within its Himalayan breeding range, with only occasional short-distance altitudinal movements to lower elevations post-breeding.^[10] Migration timing across the migratory Delichon species follows a consistent annual cycle, with post-breeding departure typically occurring from late August to September and return to breeding areas in April to May.^[1]^[9]^[8] For D. urbicum, European populations depart en masse in September–October, while D. lagopodum peaks slightly later in September–October from Siberian sites, and D. dasypus follows a similar late-summer onset from northeastern Asian breeding grounds.^[26]^[8] Routes vary by species and reflect their Palearctic breeding distributions. The western D. urbicum follows a primarily trans-Saharan path, crossing Iberia and the Mediterranean via key bottlenecks like the Strait of Gibraltar to reach sub-Saharan African winter ranges.^[27] Eastern species such as D. dasypus and D. lagopodum migrate southward through India and mainland Southeast Asia toward wintering areas in the Malay Peninsula, Indochina, and adjacent islands.^[9]^[8] All species utilize wetland stopover sites along their paths for refueling, where they congregate to exploit insect abundance before resuming flight.^[26] These long-distance migrants exhibit key physiological and behavioral adaptations to endure extended flights. Prior to departure, individuals accumulate substantial subcutaneous fat reserves—up to 10% of body mass increase per day at stopovers—to fuel non-stop segments, enabling energy-efficient travel over barriers like deserts and seas.^[28] Flocking behavior during migration further optimizes efficiency by reducing aerodynamic drag and enhancing predator vigilance, allowing coordinated passage through hazardous zones.^[29]

Predators, parasites, and interactions

House martins (Delichon spp.) are vulnerable to predation by several avian and mammalian species. Adult birds are primarily targeted by agile raptors such as the Eurasian hobby (Falco subbuteo) and Eurasian kestrel (Falco tinnunculus), which pursue them during flight.^[1] Nest predators include corvids like crows (Corvus spp.) that raid eggs, great spotted woodpeckers (Dendrocopos major) that breach nest walls, and small mammals such as rats (Rattus spp.) that consume eggs and chicks, particularly in accessible urban or rural colonies.^[1]^[30] These birds host a range of ecto- and endoparasites that can impair health and reproduction. Prominent external parasites include the house martin flea (Ceratophyllus hirundinis), which infests nests and feeds on nestlings, along with various mites (e.g., Dermanyssus spp.) and ticks that cause irritation and blood loss. Internal parasites encompass haemosporidian protozoans, notably Plasmodium species responsible for avian malaria, which are transmitted by biting midges and mosquitoes; infection prevalence in adults can reach 20-30% in European populations.^[31]^[32]^[33] Ecological interactions involve both antagonism and cooperation. House martins compete intensely with house sparrows (Passer domesticus) for nest sites under eaves and cliffs, where sparrows may evict incubating martins or destroy eggs to claim cavities. In response, colonial house martins exhibit cooperative mobbing and defense behaviors to repel sparrow intrusions. Positive interactions occur in mixed foraging flocks with swifts (Apus spp.), where group foraging dilutes individual predation risk and enhances insect detection efficiency.^[34]^[35] Predation and parasitism collectively drive substantial nestling mortality, with losses reaching up to 50% in affected broods due to flea infestations weakening chicks and predator raids on exposed nests.^[36]

Conservation

IUCN status

The four species within the genus Delichon are classified as Least Concern (LC) on the IUCN Red List as of 2024.^[2]^[18]^[16]^[37] This status is justified for each species by their extensive geographic ranges, exceeding 20,000 km² extent of occurrence (EOO)—with D. urbicum at 30,800,000 km², D. dasypus at 16,500,000 km², D. nipalense at 1,610,000 km², and D. lagopodum at 12,600,000 km²—and population trends that do not meet thresholds for decline, such as a reduction exceeding 30% over three generations or ten years.^[2]^[18]^[16]^[37] For D. urbicum, the estimated mature population of 38,300,000–80,200,000 individuals remains stable, while D. dasypus shows an increasing trend and D. lagopodum a decreasing but non-rapid one; population sizes for the latter three are unknown but do not approach the Vulnerable threshold of fewer than 10,000 mature individuals.^[2]^[18]^[37] The Nepal house martin (D. nipalense) qualifies as Least Concern despite its more restricted Himalayan distribution, owing to evidence of stable populations and no observed significant threats or declines.^[16] Recent assessments confirm no status upgrades, with 2024 evaluations maintaining LC across all species following the 2016 taxonomic split of D. lagopodum from D. urbicum and consistent 2023 reviews.^[2]^[18]^[16]^[37]

Population trends and threats

The population of the Northern House Martin (Delichon urbicum) has experienced regional declines across parts of Europe, with an estimated 20-30% reduction since the 1970s in western and central regions, driven by varying local pressures.^[38] In the United Kingdom, populations have fallen by approximately 25% from 1995 to 2020, with further declines of around 40% in the decade to 2024, contributing to its Red List status for conservation concern.^[39]^[40] As of 2025, UK populations continue to decline, per the latest Breeding Bird Survey.^[41] Despite these trends, the overall European population remains stable at 23-48 million mature individuals, as broader estimates account for stable or increasing numbers in eastern regions.^[2] In Asia, populations of D. urbicum and closely related species like the Siberian House Martin (D. lagopodum) appear stable, though data are sparse outside of breeding range estimates in China (100-10,000 pairs).^[37] The Nepal House Martin (D. nipalense) is also considered stable, with no evidence of declines despite limited monitoring in the Himalayas.^[16] Recent eBird observations indicate no major population shifts, though southern Asian monitoring gaps persist, particularly for D. nipalense and D. lagopodum.^[42] Key threats to Delichon species include the widespread use of insecticides, which reduce aerial insect prey availability essential for foraging.^[2] Building modernization and renovations in urban areas frequently destroy or prevent nest sites on eaves and walls, exacerbating habitat loss in Europe.^[43] Climate change poses additional risks by altering migration timings, extending desert barriers like the Sahara, and causing droughts that limit mud for nest construction and food resources.^[44] In southern Asia, inadequate monitoring hinders threat assessment for endemic taxa like D. nipalense.^[16] Conservation efforts in Europe focus on nest box programs, which provide artificial breeding sites and have shown effectiveness in supporting D. urbicum populations post-building renovations.^[45] Regulatory measures on pesticide use aim to mitigate insect declines, while ongoing citizen science monitoring through platforms like eBird enhances post-2023 species tracking.^[42] In Asia, similar interventions remain underdeveloped due to data limitations. Looking ahead, continued declines in D. urbicum could elevate its status to Near Threatened regionally, underscoring the need for expanded research on understudied species like D. lagopodum and D. nipalense to inform targeted protections.^[2]^[46]

References

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Oct 24, 2023 · All members of the genus Delichon have structurally similar vocalizations, and in many cases differences, if any, are rather subtle to the human ...
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Northern House Martin Delichon Urbicum Species Factsheet
This species has an extremely large range and the population size is extremely large, hence does not approach threatened thresholds for the range or population ...
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DELICHON Definition & Meaning - Merriam-Webster
a genus of swallows with feathered feet that includes the European martin (D. urbica). Word History. Etymology. New Latin, anagram of Chelidon ...
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Notes on the Generic Classification of the Swallows, Hirundinidæ
Aug 9, 2025 · We also found that Delichon, which has persisted in the nomenclature as a genus separate from Hirundo, is monophyletic with taxa that are ...
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Updates and Corrections—October 2023 – Clements Checklist
Oct 27, 2023 · Siberian House-Martin Delichon lagopodum is split from Western (formerly Common) House-Martin D. urbicum (Clements 2007:361). Summary: The ...
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[7]
Siberian House-Martin Delichon lagopodum - Birds of the World
Oct 24, 2023 · 13–14 cm. Adult has very clean blue-black and white plumage, with sharply defined cap not extending to cheeks or chin; upperparts principally steel blue-black.
[8]
Asian House-Martin Delichon dasypus - Birds of the World
12–13 cm; 18 g. Has glossy blue crown and back , white rump and shorter uppertail-coverts; wings and tail blackish brown, tail slightly forked.
[9]
Nepal House-Martin Delichon nipalense - Birds of the World
Nominate race common to fairly common; widespread and fairly common in Nepal, locally fairly common in India, common in Bhutan.
[10]
(PDF) Neogene songbirds (Aves, Passeriformes) from Hungary
Neogene songbirds (Aves, Passeriformes) from Hungary. January 2013; Hantkeniana. Authors: Eugen Kessler at Eötvös Loránd University · Eugen Kessler · Eötvös ...
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Swallows and martins are instantly recognisable by their slender, streamlined bodies, long, pointed wings and small bills: all adaptations for hunting insects ...
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Breeding season‐specific sex diagnostics in the monomorphic ...
Capsule Breeding adult females show a bare brood patch and a smaller cloacal protuberance than males. Aims To examine the degree of sexual dimorphism in ...
[13]
Nepal House-Martin Delichon nipalense - eBird
A typical house-martin, with dark upperparts, white underparts, a white rump, and a rather dumpy body. Differs from Common and Asian House-Martins by its sooty ...
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Small, compact swallow with dark (glossy dark blue) upperparts, smudgy gray cast on whitish underparts, and bright white rump. Very similar to Northern and ...Missing: vocalizations | Show results with:vocalizations
[15]
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The global population size has not been quantified, but the species is reported to be widespread and fairly common in Nepal and locally fairly common in India ...
[16]
Breeding Habitat Selection in the House Martin Delichon urbica in ...
House Martins selected areas with a larger proportion of old buildings and open spaces, and closer to the nearest sources of food or mud. Only the distance from ...Missing: genus | Show results with:genus
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This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion.Missing: body weight wingspan<|separator|>
[18]
Nepal House Martin - Delichon nipalense - Oiseaux.net
Identification record : Nepal House Martin (Delichon nipalense) is a ... Size. : 12 cm. Wingspan. : -. Weight. : 14 à 16 g. Geographic range. Distribution.
[19]
Siberian House-Martin Delichon lagopodum - eBird
Very similar to Asian House-Martin, but note white rump patch extending further up back, brighter white underparts, and slightly larger size.
[20]
Landscape structure and site characteristics influence whether the ...
Sep 8, 2024 · Here we analysed the characteristics and conditions that determined whether the northern house martin Delichon urbicum occupied more than 300 ...
[21]
[PDF] Breeding biology of Asian House Martin Delichon dasypus in a high ...
The nest of Asian House Martin is a closed cup typical of hirundines, built with tiny mud pellets and then lined with dried moss, 'sear' grasses and ...
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https://orientalbirdclub.org/wp-content/uploads/2013/01/Asian-House-Martin.pdf
[23]
Feeding Behaviour and the Role of Insects in the Diet of Northern ...
(PDF) Feeding Behaviour and the Role of Insects in the Diet of Northern House-Martin ( Delichon urbica meridionalis ) Nestlings in Northeastern Algeria.
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House Martin, Swift or Swallow? How to Tell the Difference - RSPB
You might see them skimming over lakes and rivers, scooping up water to drink. A group of six Swallows perched on a branch. A group of Swallows. Call/song.
[25]
Migration of Common House Martin - Swiss Ornithological Institute
The Common House Martin (Delichon urbicum) is a long-distance migrant breeding across Europe and spending the non-breeding period in sub-Saharan Africa.Missing: dasypus lagopodum nipalense
[26]
Around the Mediterranean: an extreme example of loop migration in ...
Dec 14, 2017 · The birds reached their wintering sites over a relatively wide interval from 28 September to 4 November (mean: 11 October, Supplementary ...
[27]
Have Wings, Will Travel: Avian Adaptations for Migration
Jan 1, 1996 · A migratory bird can increase its body weight through fat deposition by as much as 10% per day (usually 1-3%).Missing: delichon flocking
[28]
House Martin | BTO
Listen to example recordings of the main vocalisations of House Martin, provided by xeno-canto contributors. ... of population dynamics of Common House-Martin ...<|control11|><|separator|>
[29]
Opportunistic killing and partial predation of a Common House ...
We provide the first documented predation event involving the opportunistic killing of a Common House Martin (Delichon urbicum) by a juvenile Grey Heron (Ardea ...
[30]
(PDF) Annual cycle of Ceratophyllus hirundinis (Curtis, 1826 ...
The annual cycle of C. hirundinis was studied in 61 nests of Delichon urbica. Fleas were found in the 45 nests. In the number of adults two peaks were observed, ...
[31]
(PDF) Ectoparasites of Portuguese House Martins Delichon urbica
Feb 2, 2025 · Forty four House Martins were examined for ectoparasites from four locations in Portugal. The wing louse Bruelia gracilis was found at all ...
[32]
Dutch House Martins Delichon urbicum gain blood parasite ...
Feb 21, 2012 · We here report on the occurrence of malaria in 112 fledgling and 358 adult House Martins from The Netherlands. Repeatability of molecular essays was 94.4%.Missing: scientific | Show results with:scientific
[33]
(PDF) Cooperative defense of colonial breeding house martins ...
Aug 6, 2025 · Cooperative defense of colonial breeding house martins (Delichon urbicum) against nest-usurping house sparrows (Passer domesticus). December ...
[34]
House Martin Support Suffolk
As we know hirundines – Swallows and Martins, are often a confusion species with Swifts, especially when feeding together in mixed flocks early after ...
[35]
What drives population-level effects of parasites? Meta-analysis ...
A recent meta-analytical synthesis of parasite induced mortality of nestlings showed an overall small effect (12% mean parasite-induced mortality, range 0–89%, ...
[36]
Eastern House Martin Lagopodum Species Factsheet
Habitat classification ; Forest, Subtropical/Tropical Moist Lowland, Non-breeding, Suitable ; Grassland, Subtropical/Tropical Dry, Non-breeding, Suitable.
[37]
Status of House Martin Delichon urbicum in European countries ...
Results show the species as decreasing in 17 coun- tries, stable in eight, increasing in five, with an unknown status in 13 and fluctuating in one country.
[38]
Wild bird populations in the UK and England, 1970 to 2024 - GOV.UK
Sep 23, 2025 · Indicator trend description: Woodland birds Woodland bird populations have declined by 32% in the UK and 36% in England since 1970.Missing: House | Show results with:House
[39]
Swallow, swift and house martin populations have nearly halved ...
May 16, 2024 · Populations of these insect-eating birds have dropped by 40% or more in the past decade, according to the latest Breeding Bird Survey (BBS) report.Missing: 1970-2025 | Show results with:1970-2025
[40]
2023 Taxonomy Update—COMPLETE - eBird
Oct 24, 2023 · The Clements Checklist is updated annually to reflect the latest developments in avian taxonomy. “Taxonomy Time”, as we like to call it, is a ...Ibera Seedeater Sporophila... · Notable Splits · Red Junglefowl (domestic...
[41]
eBird Status - Data Version 2023
Access to the most recent (currently this version) of eBird Status and Trends Data Products is available on the Download Data Products page.Missing: Delichon monitoring
[42]
Intensive agriculture, particularly an ***increase in pesticides and ...
May 24, 2023 · Swallow, swift and house martin populations have nearly ... insect numbers, loss of habitat and extreme weather due to climate change.We run a House Martin ANC project in southern England ... - FacebookSobering, indeed. REASONS FOR THIS? Habitat loss via changingMore results from www.facebook.com
[43]
Insights from nationwide citizen science data in the Czech Republic
We investigated how land cover composition affects the abundance of House Martins on the landscape scale by using nationwide citizen science data.<|separator|>
[44]
House Martin Conservation UK & Ireland
House martins nest in colonies and pairs can raise two or three broods of young during the course of a breeding season which can last into September/October.<|separator|>
[45]
Effectiveness of using nest boxes as a form of bird protection after ...
Nov 24, 2021 · In this study, we investigated the use of nest boxes as a bird conservation measure after buildings were thermally modernized.
[46]
Siberian House Martin 遠東毛腳燕 - Avifauna HK
Jun 23, 2023 · In adult plumage, pure white uppertail coverts result in a large clean white rump patch. The typical contact call is lower-pitched than that of ...