Black kite

The black kite (Milvus migrans) is a medium-sized bird of prey in the family Accipitridae, which also includes many other diurnal raptors. It is thought to be the world's most abundant species of Accipitridae, although some populations have experienced dramatic declines or fluctuations.[2] Current global population estimates run up to 6 million individuals.[1]

Black kite
M. m. affinis, Australia
Calls
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Class: Aves
Order: Accipitriformes
Family: Accipitridae
Genus: Milvus
Species:
M. migrans
Binomial name
Milvus migrans
(Boddaert, 1783)
Subspecies

5, see text

Range of black and yellow-billed kites
  Breeding
  Resident
  Non-breeding
  Passage
Synonyms
  • Falco migrans Boddaert, 1783
  • Milvus affinis
  • Milvus ater
  • Milvus melanotis
Black kite in Hanoi Zoo

Unlike others of the group, black kites are opportunistic hunters and are more likely to scavenge. They spend much time soaring and gliding in thermals in search of food. Their angled wing and distinctive forked tail make them easy to identify. They are also vociferous with a shrill whinnying call.

The black kite is widely distributed through the temperate and tropical parts of Eurasia and parts of Australasia and Oceania, with the temperate region populations tending to be migratory. Several subspecies are recognized and formerly had their own English names. The European populations are small, but the South Asian population is very large.

Systematics and taxonomy

The black kite was described by the French polymath Georges-Louis Leclerc, Comte de Buffon in his Histoire Naturelle des Oiseaux in 1770.[3] The bird was also illustrated in a hand-coloured plate engraved by François-Nicolas Martinet in the Planches Enluminées D'Histoire Naturelle which was produced under the supervision of Edme-Louis Daubenton to accompany Buffon's text.[4] Neither the plate caption nor Buffon's description included a scientific name but in 1783 the Dutch naturalist Pieter Boddaert coined the binomial name Falco migrans in his catalogue of the Planches Enluminées.[5] The type locality is France.[6] The current genus Milvus was erected by the French naturalist Bernard Germain de Lacépède in 1799.[7] Milvus is the Latin word for a red kite; the specific migrans means "migrating" from the Latin migrare "to migrate".[8]

The red kite has been known to hybridize with the black kite (in captivity where both species were kept together, and in the wild on the Cape Verde Islands).[9]

Recent DNA studies suggest that the yellow-billed African races parasitus and aegyptius differ significantly from black kites in the Eurasian clade, and should be considered a separate allopatric species: yellow-billed kite, M. aegyptius.[10] They occur throughout Africa except for the Congo Basin and the Sahara Desert. There have been some suggestions that the black-eared kite (M. m. lineatus) should be elevated to full species status as M. lineatus, but this is not well supported.[11]

Subspecies

Five subspecies are recognised.[12]

  • M. m. migrans(Boddaert, 1783): European black kite
Breeds central, southern and eastern Europe, as well as the Maghreb region of Northwest Africa, to Tien Shan and south to northwest Pakistan. Winters in Sub-Saharan Africa. The head is whitish.
  • M. m. lineatus(J. E. Gray, 1831): black-eared kite
Siberia to Amurland south around Himalaya to north India, north Indochina and south China; Japan. Northern inland birds migrate to east Persian Gulf coast and south Asia in winter. This has a larger pale carpal patch.
  • M. m. govindaSykes, 1832: small Indian kite (formerly pariah kite)
Eastern Pakistan east through tropical India and Sri Lanka to Indochina and Malay Peninsula. Resident. A dark brown kite found throughout the subcontinent. Can be seen circling and soaring in urban areas. Easily distinguished by the shallow forked tail. The name pariah originates from the Indian caste system and usage of this name is deprecated.[13][14]
  • M. m. affinisGould, 1838: fork-tailed kite
Sulawesi and possibly Lesser Sunda Islands; Papua New Guinea except mountains; northeast and east Australia.
  • M. m. formosanusKuroda, 1920: Taiwan kite
Taiwan and Hainan; resident.

Description

M. m. govinda, India

Black kites can be distinguished from red kites by the slightly smaller size, less forked tail (visible in flight), and generally dark plumage without any rufous. The sexes are alike though the male is a little smaller and less aggressive (this is the case in most birds of prey). They weigh on average 735 grams.[15] The upper plumage is brown but the head and neck tend to be paler. The patch behind the eye appears darker. The outer flight feathers are black and the feathers have dark cross bars and are mottled at the base. The lower parts of the body are pale brown, becoming lighter towards the chin. The body feathers have dark shafts giving it a streaked appearance. The cere and gape are yellow, but the bill is black (unlike that of the yellow-billed kite). The legs are yellow and the claws are black. They have a distinctive shrill whistle followed by a rapid whinnying call. Males and females have the same plumage but females are longer than males and have a little larger wingspan. Their wingspan is around 150 cm.[16]

Distribution

The species is found in Europe, Asia, Africa and Australia. The temperate populations of this kite tend to be migratory while the tropical ones are resident. European and central Asian birds (subspecies M. m. migrans and black-eared kite M. m. lineatus, respectively) are migratory, moving to the tropics in winter, but races in warmer regions such as the Indian M. m. govinda (small Indian/pariah kite), or the Australasian M. m. affinis (fork-tailed kite), are resident. In some areas such as in the United Kingdom, the black kite occurs only as a wanderer on migration. These birds are usually of the nominate race, but in November 2006 a juvenile of the eastern lineatus, not previously recorded in western Europe, was found in Lincolnshire.[17]

The species is not found in the Indonesian archipelago between the South East Asian mainland and the Wallace Line.[18] Vagrants, most likely of the black-eared kite, on occasion range far into the Pacific, out to the Hawaiian islands.[19][20]

In India, the population of M. m. govinda is particularly large especially in areas of high human population. Here the birds avoid heavily forested regions. A survey in 1967 in the 150 square kilometres of the city of New Delhi produced an estimate of about 2200 pairs or roughly 15 per square kilometre.[16][21] Another survey in 2013 estimated 150 pairs for every 10 square kilometres.[22]

Vagrants from Australia occasionally reach New Zealand, however, only one individual has persisted there (currently ~21 years old).[23]

Behaviour and ecology

Food and foraging

Black kites are most often seen gliding and soaring on thermals as they search for food. Their flight is buoyant and the bird glides effortlessly, changing directions easily. They will swoop down with their legs lowered to snatch small live prey, fish, household refuse and carrion, for which behaviour they are known in British military slang as the shite-hawk. They are opportunist hunters and have been known to take birds, bats,[24] and rodents.[25] They are attracted to smoke and fires, where they seek escaping prey.[26] Kites are also known to spread fires by picking and dropping burning twigs so as to flush prey,[27][28] leading to them being known in some circles as "firehawks".[29] The Indian populations are well adapted to living in cities and are found in densely populated areas. Large numbers may be seen soaring in thermals over cities. In some places, they will readily swoop and snatch food held by humans.[16][30] In Delhi, where black kites breed within the cities, religious offerings of meat to the kites are common among those who practice Islam. The meat is thrown into the air and the kites dive-bomb for the meat. Humans who are in the vicinity may suffer serious injury due to the sharp talons of the kites. The reinforcement between human proximity and being fed have decreased the kite's fear of humans.[31] Black kites in Spain prey on nestling waterfowl especially during summer to feed their young. Predation of nests of other pairs of black kites has also been noted.[32] Kites have also been seen to tear and carry away the nests of baya weavers in an attempt to obtain eggs or chicks.[33]

Flocking and roosting

Black kite impersonating an osprey, Nepal

In winter, kites form large communal roosts. Flocks may fly about before settling at the roost.[30] When migrating, the black kite has a greater propensity to form large flocks than other migratory raptors, particularly prior to making a crossing over water.[34] In India, the subspecies govinda shows large seasonal fluctuations with the highest numbers seen from July to October, after the monsoons, and it has been suggested that they make local movements in response to high rainfall.[35]

Breeding

The breeding season of the black kite in India begins in winter (mainly January and February[36]), the young birds fledging before the monsoons. The nest is a rough platform of twigs and sticks placed in a tree. Nest sites may be reused in subsequent years. European birds breed in summer. Birds in the Italian Alps tend to build their nest close to water in steep cliffs or tall trees.[37] Nest orientation may be related to wind and rainfall.[38] The nests may sometimes be decorated with bright materials such as white plastic and a study in Spain suggests that they may have a role in signalling to keep away other kites.[39]

After pairing, the male frequently copulates with the female. Unguarded females may be approached by other males, and extra pair copulations are frequent. Males returning from a foraging trip will frequently copulate on return, as this increases the chances of his sperm fertilizing the eggs rather than a different male.[40] Both the male and female take part in nest building, incubation and care of chicks.

Eggs

The typical clutch size is 2 or sometimes 3 eggs.[30][41] The incubation period varies from 30 to 34 days. Chicks of the Indian population stay at the nest for nearly two months.[36] Chicks hatched later in European populations appear to fledge faster. The care of young by the parents also rapidly decreased with the need for adults to migrate.[42][43] Siblings show aggression to each other and often the weaker chick may be killed, but parent birds were found to preferentially feed the smaller chicks in experimentally altered nests.[44]

Newly hatched young have down (prepennae) which are sepia on the back and black around the eye and buff on the head, neck and underparts. This is replaced by brownish-gray second down (preplumulae). After 9–12 days, the second down appears on the whole body except the top of the head. Body feathers begin to appear after 18 to 22 days. The feathers on the head become noticeable from the 24th to 29th day. The nestlings initially feed on food fallen at the bottom of the nest and begin to tear flesh after 33–39 days. They are able to stand on their legs after 17–19 days and begin flapping their wings after 27–31 days. After 50 days, they begin to move to branches next to the nest.[45][46] Birds are able to breed after their second year.[36] Parent birds guard their nest and will dive aggressively at intruders. Humans who intrude the nest appear to be recognized by birds and singled out for dive attacks.[47]

Mortality factors

Black-eared kites in Japan were found to accumulate nearly 70% of mercury accumulated from polluted food in the feathers, thus excreting it in the moult process.[48] Black kites often perch on electric wires and are frequent victims of electrocution.[49][50] Their habit of swooping to pick up dead rodents or other roadkill leads to collisions with vehicles.[51] Instances of mass poisoning as a result of feeding on poisoned voles in agricultural fields have been noted.[52] They are also a major nuisance at some airports, where their size makes them a significant birdstrike hazard.[53]

As a large raptorial bird, the black kite has few natural predators. However, they do have a single serious predator: the Eurasian eagle-owl (Bubo bubo). The eagle-owl freely picks off kites of any age and eagle-owls were noted to precipitously decrease kite breeding success when nesting within kilometres of the kites in the Italian Alps.[54] Like most bird species, they have parasites; several species of endoparasitic trematodes are known[55] and some Digenea species that are transmitted via fishes.[56][57][58]

Birds with abnormal development of a secondary upper mandible have been recorded in govinda[59] and lineatus subspecies.[60]

References

  1. BirdLife International (2020). "Milvus migrans". IUCN Red List of Threatened Species. 2020: e.T181568721A181571544. doi:10.2305/IUCN.UK.2020-3.RLTS.T181568721A181571544.en. Retrieved 13 November 2021.
  2. Ferguson-Lees, J.; Christie, D. (2001). Raptors of the World. London: Christopher Helm. ISBN 978-0-7136-8026-3.
  3. Buffon, Georges-Louis Leclerc de (1770). Histoire Naturelle des Oiseaux (in French). Vol. 1. Paris: De L'Imprimerie Royale. p. 286.
  4. Buffon, Georges-Louis Leclerc de; Martinet, François-Nicolas; Daubenton, Edme-Louis; Daubenton, Louis-Jean-Marie (1765–1783). "Le Milan noir". Planches Enluminées D'Histoire Naturelle. Vol. 5. Paris: De L'Imprimerie Royale. Plate 472.
  5. Boddaert, Pieter (1783). Table des planches enluminéez d'histoire naturelle de M. D'Aubenton : avec les denominations de M.M. de Buffon, Brisson, Edwards, Linnaeus et Latham, precedé d'une notice des principaux ouvrages zoologiques enluminés (in French). Utrecht. p. 28, Number 472.
  6. Mayr, Ernst; Cottrell, G. William, eds. (1979). Check-list of Birds of the World. Vol. 1 (2nd ed.). Cambridge, Massachusetts: Museum of Comparative Zoology. p. 297.
  7. Lacépède, Bernard Germain de (1799). "Tableau des sous-classes, divisions, sous-division, ordres et genres des oiseux". Discours d'ouverture et de clôture du cours d'histoire naturelle (in French). Paris: Plassan. p. 4. Page numbering starts at one for each of the three sections.
  8. Jobling, James A. (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. p. 255. ISBN 978-1-4081-2501-4.
  9. Hille, Sabine; Thiollay, Jean-Marc (2000). "The imminent extinction of the kites Milvus milvus fasciicauda and Milvus m. migrans on the Cape Verde Islands". Bird Conservation International. 10 (4): 361–369. doi:10.1017/S0959270900000319.
  10. Johnson, J.A.; Watson, Richard T.; Mindell, David P. (2005). "Prioritizing species conservation: does the Cape Verde kite exist?". Proceedings of the Royal Society B. 272 (1570): 1365–1371. doi:10.1098/rspb.2005.3098. PMC 1560339. PMID 16006325.
  11. Schreiber, Arnd; Stubbe, Michael; Stubbe, Annegret (2000). "Red kite (Milvus milvus) and black kite (M. migrans): minute genetic interspecies distance of two raptors breeding in a mixed community (Falconiformes: Accipitridae)". Biological Journal of the Linnean Society. 69 (3): 351–365. doi:10.1111/j.1095-8312.2000.tb01210.x.
  12. Gill, Frank; Donsker, David; Rasmussen, Pamela, eds. (July 2023). "Hoatzin, New World vultures, Secretarybird, raptors". IOC World Bird List Version 13.2. International Ornithologists' Union. Retrieved 3 September 2023.
  13. Agoramoorthy, G. (2005). "Disallow caste discrimination in biological and social contexts" (PDF). Current Science. 89 (5): 727.
  14. Blanford, W.T. (1896). Fauna of British India. Birds. Vol. 3. London: Taylor and Francis. pp. 374–378.
  15. "Black Kite data". Encyclopedia of Life. Retrieved Dec 30, 2022.
  16. Whistler, Hugh (1949). Popular handbook of Indian birds (4th ed.). London: Gurney and Jackson. pp. 371–373. ISBN 978-1-4067-4576-4.
  17. Badley, John; Hyde, Philip (2006). "The Black-eared kite in Lincolnshire - a new British bird". Birding World. 19 (11): 465–470.
  18. Reich, Nathan; Sorenson, Amanda (2011). "Milvus migrans black kite". Animal Diversity. University of Michigan Museum of Zoology. Retrieved 21 October 2021.
  19. "Milvus migrans additional details on distribution". globalraptors.org. The Peregrine Fund. 2012. Retrieved 2021-10-21.
  20. "The 115th Christmas Bird Count in Hawaii & the Pacific Islands". Audubon.org. National Audubon Society. 2015. Retrieved 2021-10-21.
  21. Galushin, V.M. (1971). "A huge urban population of birds of prey in Delhi, India". Ibis. 113 (4): 552. doi:10.1111/j.1474-919x.1971.tb05189.x.
  22. Kumar, Nishant; Mohan, Dhananjai; Jhala, Yadvendradev V.; Qureshi, Qamar; Sergio, Fabrizio (2014). "Density, laying date, breeding success and diet of Black Kites Milvus migrans govinda in the city of Delhi (India)". Bird Study. 61 (1): 1–8. doi:10.1080/00063657.2013.876972.
  23. "Wingspan Birds of Prey Trust". Wingspan Birds of Prey Trust. 25 October 2012. Retrieved 22 January 2013.
  24. Mikula, Peter; Morelli, Federico; Lučan, Radek K.; Jones, Darryl N.; Tryjanowski, Piotr (2016). "Bats as prey of diurnal birds: A global perspective". Mammal Review. 46 (3): 160–174. doi:10.1111/mam.12060.
  25. Narayanan, E. (1989). "Pariah kite Milvus migrans capturing Whitebreasted Kingfisher Halcyon smyrnensis". Journal of the Bombay Natural History Society. 86 (3): 445.
  26. Hollands, David (1984). Eagles, hawks, and falcons of Australia. Nelson. ISBN 978-0-17-006411-8.
  27. Chisholm, A.H. (1971). "The use by birds of tools and playthings". Victorian Naturalist. 88: 180–188.
  28. Bonta, Mark; Gosford, Robert; Eussen, Dick; Ferguson, Nathan; Loveless, Erana; Witwer, Maxwell (2017). "Intentional Fire-Spreading by "Firehawk" Raptors in Northern Australia". Journal of Ethnobiology. 37 (4): 700. doi:10.2993/0278-0771-37.4.700. S2CID 90806420.
  29. "Australian "Firehawk" Raptors Intentionally Spread Wildfires". 12 January 2018.
  30. Ali, S.; Ripley, S.D. (1978). Handbook of the birds of India and Pakistan. Vol. 1 (2nd ed.). Oxford University Press. pp. 226–230. ISBN 978-0-19-562063-4.
  31. "Bird Attacks on Humans - 7 Alarming Tales". Birds At First Sight. 2022-09-25. Retrieved 2022-09-25.
  32. Veiga, J.P.; Hiraldo, F. (1990). "Food habits and the survival and growth of nestlings in two sympatric kites (Milvus milvus and Milvus migrans)". Holarct. Ecol. 13: 62–71. doi:10.1111/j.1600-0587.1990.tb00590.x.
  33. Wesley, H. Daniel; Relton, A.; Moses, A. Alagappa (1991). "A strange predatory habit of the Pariah kite Milvus migrans". Journal of the Bombay Natural History Society. 88 (1): 110–111.
  34. Agostini, N.; Duchi, A. (1994). "Water-crossing behavior of Black Kites (Milvus migrans) during migration" (PDF). Bird Behavior. 10: 45–48. doi:10.3727/015613894791748935. Archived from the original (PDF) on 2016-03-03. Retrieved 2010-07-03.
  35. Mahabal, Anil; Bastawade, D.B. (1985). "Population ecology and communal roosting behaviour of pariah kite Milvus migrans govinda in Pune (Maharashtra)". Journal of the Bombay Natural History Society. 82 (2): 337–346.
  36. Desai, J.H.; Malhotra, A.K. (1979). "Breeding biology of the Pariah Kite Milvus migrans at Delhi Zoological Park". Ibis. 121 (3): 320–325. doi:10.1111/j.1474-919X.1979.tb06849.x.
  37. Sergio, Fabrizio; Pedrini, Paolo; Marchesi, Luigi (2003). "Adaptive selection of foraging and nesting habitat by black kites (Milvus migrans) and its implications for conservation: a multi-scale approach". Biological Conservation. 112 (3): 351–362. doi:10.1016/S0006-3207(02)00332-4.
  38. Viñuela, J.; Sunyer, C. (1992). "Nest orientation and hatching success of Black Kites Milvus migrans in Spain". Ibis. 134 (4): 340–345. doi:10.1111/j.1474-919X.1992.tb08013.x.
  39. Sergio, F.; Blas, J.; Blanco, G.; Tanferna, A.; Lopez, L.; Lemus, J.A.; Hiraldo, F. (2011). "Raptor Nest Decorations Are a Reliable Threat Against Conspecifics". Science. 331 (6015): 327–330. Bibcode:2011Sci...331..327S. doi:10.1126/science.1199422. hdl:10261/37071. PMID 21252345. S2CID 13925885.
  40. Koga, K.; Shiraishi, S. (1994). "Copulation behaviour of the Black Kite Milvus migrans in Nagasaki Peninsula". Bird Study. 41 (1): 29–36. doi:10.1080/00063659409477194.
  41. Koga, Kimiya; Siraishi, Satoshi; Uchida, Teruaki (1989). "Breeding Ecology of the Black-eared Kite Milvus migrans lineatus in the Nagasaki Peninsula, Kyushu". Japanese Journal of Ornithology. 38 (2): 57–66. doi:10.3838/jjo.38.57.
  42. Bustamante, J.; Hiraldo, F. (1989). "Post-fledging dependence period and maturation of flight skills in the Black Kite Milvus migrans". Bird Study. 56 (3): 199–204. doi:10.1080/00063658909477025. hdl:10261/46912.
  43. Bustamante, J. (1994). "Family break-up in Black and Red Kites Milvus migrans and Milvus milvus:is time of independence an offspring decision" (PDF). Ibis. 136 (2): 176–184. doi:10.1111/j.1474-919X.1994.tb01082.x. hdl:10261/46920. Archived from the original (PDF) on 2011-07-20. Retrieved 2010-07-03.
  44. Viñuela, Javier (1999). "Sibling aggression, hatching asynchrony, and nestling mortality in the black kite ( Milvus migrans )". Behavioral Ecology and Sociobiology. 45 (1): 33–45. doi:10.1007/s002650050537. S2CID 44011901.
  45. Desai, J.H.; Malhotra, A.K. (1980). "Embryonic development of Pariah Kite Milvus migrans govinda". Journal of the Yamashina Institute for Ornithology. 12 (3): 82–86. doi:10.3312/jyio1952.12.3_220.
  46. Koga, Kimiya; Shiraishi, Satoshi; Uchida, Teruaki (1989). "Growth and Development of the Black-eared Kite Milvus migrans lineatus". Japanese Journal of Ornithology. 38 (1): 31–42. doi:10.3838/jjo.38.31.
  47. Malhotra, A.K. (1990). "Site fidelity and power of recognition in Pariah Kite Milvus migrans govinda". Journal of the Bombay Natural History Society. 87 (3): 458.
  48. Honda, K.; Nasu, T.; Tatsukawa, R. (1986). "Seasonal changes in mercury accumulation in the black-eared kite, Milvus migrans lineatus". Environmental Pollution Series A, Ecological and Biological. 42 (4): 325–334. doi:10.1016/0143-1471(86)90016-4.
  49. Ferrer, Miguel; de la Riva, Manuel; Castroviejo, Javier (1991). "Electrocution of Raptors on Power Lines in Southwestern Spain". Journal of Field Ornithology. 62 (2): 181–190. JSTOR 4513623.
  50. Janss, G.F.E. (2000). "Avian mortality from power lines: a morphologic approach of a species-specific mortality". Biological Conservation. 95 (3): 353–359. doi:10.1016/S0006-3207(00)00021-5. hdl:10261/64776.
  51. Cooper, J.E. (1973). "Post-mortem findings in East African birds of prey". Journal of Wildlife Diseases. 9 (4): 368–375. doi:10.7589/0090-3558-9.4.368. PMID 4150320. S2CID 37028748.
  52. Mendelssohn, H.; Paz, U. (1977). "Mass mortality of birds of prey caused by Azodrin, an organophosphorus insecticide". Biological Conservation. 11 (3): 163. doi:10.1016/0006-3207(77)90001-5.
  53. Owino, A.; Biwott, N.; Amutete, G. (2004). "Bird strike incidents involving Kenya Airways flights at three Kenyan airports, 1991-2001". African Journal of Ecology. 42 (2): 122–128. doi:10.1111/j.1365-2028.2004.00507.x.
  54. Sergio, F.; Marchesi, L.; Pedrini, P. (2003). "Spatial refugia and the coexistence of a diurnal raptor with its intraguild owl predator". Journal of Animal Ecology. 72 (2): 232–245. doi:10.1046/j.1365-2656.2003.00693.x.
  55. Karyakarte, P.P. (1970). "A new species of Echinochasmus (Trematoda: Echinostomatidae) from the kite, Milvus migrans (Boddaert), in India". Rivista di Parassitologia. 31 (2): 113–116. PMID 5529542.
  56. Seo, M.; Guk, S.M.; Chai, J.Y.; Sim, S.; Sohn, W, M. (2008). "Holostephanus metorchis (Digenea: Cyathocotylidae) from Chicks Experimentally Infected with Metacercariae from a Fish, Pseudorasbora parva, in the Republic of Korea". The Korean Journal of Parasitology. 46 (2): 83–86. doi:10.3347/kjp.2008.46.2.83. PMC 2532613. PMID 18552543.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  57. Lal, Makund Behari (1939). "Studies in Helminthology-Trematode parasites of birds". Proceedings of the Indian Academy of Sciences, Section B. 10 (2): 111–200. doi:10.1007/BF03039971. S2CID 81103601.
  58. Sheena, P.; Manjula, K.; Subair, K.; Janardanan, K. (2007). "The life cycle of Mesostephanus indicum Mehra, 1947 (Digenea: Cyathocotylidae)". Parasitology Research. 101 (4): 1015–1018. doi:10.1007/s00436-007-0579-7. PMID 17514481. S2CID 733816.
  59. Rawal, U.M. (1971). "Pariah Kite with Double Bill" (PDF). The Auk. 88 (1): 166. doi:10.2307/4083971. JSTOR 4083971.
  60. Biswas, Biswamoy (1956). "A Large Indian Kite Milvus migrans lineatus (Gray) with a split bill". Journal of the Bombay Natural History Society. 53 (3): 474–475.

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