Bronze-winged jacana

The bronze-winged jacana (Metopidius indicus) is a wader in the family Jacanidae. It is found across South and Southeast Asia and is the sole species in the genus Metopidius. Like other jacanas it forages on lilies and other floating aquatic vegetation, the long feet spreading out its weight and preventing sinking. The sexes are alike but females are slightly larger and are polyandrous, maintaining a harem of males during the breeding season in the monsoon rains. Males maintain territories, with one male in the harem chosen to incubate the eggs and take care of the young. When threatened, young chicks may be carried to safety by the male under his wings.

Bronze-winged jacana
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Charadriiformes
Family: Jacanidae
Genus: Metopidius
Wagler, 1832
Species:
M. indicus
Binomial name
Metopidius indicus
(Latham, 1790)
Synonyms

Parra indica protonym
Parra aenea Cuvier

Taxonomy and systematics
 
 
 

Jacana

 
 

Hydrophasianus

 
 
 
 
 
 

Microparra

 
 

Irediparra

 
 
 

Metopidius

 
 
 

Actophilornis

 
 
 
Phylogeny of the Jacanidae based on an analysis of mitochondrial gene sequences[2]

The bronze-winged jacana was formally described by the English ornithologist John Latham in 1790 and given the binomial name Parra indica. He placed it in the genus Parra along with all the other jacanas.[3][4] Latham had earlier included the species in a supplement to his A General Synopsis of Birds but had not coined a scientific name.[5] The present genus Metopidius was introduced by the German zoologist Johann Georg Wagler in 1832.[6] The bronze-winged jacana is the only species within the genus.[7] The name Metopidius is from the Ancient Greek word metōpidios meaning "on the forehead", referring to the frontal lappet. The specific epithet indicus is the Latin word for "Indian".[8] There are no recognised subspecies.[9]

A comparison of the wing bones

Like other jacanas it has 10 tail feathers and the oil gland is tufted.[10] Many jacana species have a carpal spur that is used in territorial fights. In some species the spur is reduced but the wing bones are modified. The carpal spur is reduced to a tubercle in the bronze-winged jacana. In the genera Actophilornis, and Irediparra the radius bone is flattened and blade-like (and associated with a reduced spur[11]) and is thought to be an adaptation either for territorial combat, or for brooding eggs and carrying young under the wings.[12][13][2] In Metopidius, the radius curves and diverges to form a broad gap between the radius and ulna.[14] Male jacanas, based on observations in the African jacana, incubate eggs and move their forewings under the eggs so as to hold them between the body and the wing. This behaviour known as wing-brooding may be aided by the flattened radius bone.[15]

Description

Bronze-winged jacanas are rail-like, large, short tailed birds that appear dark at a distance except for the supercilium.[16] They are 29 cm (11 in) in length. The sexes are similar but the females are slightly larger than the males.[17] The wings are bronzy brown with a green sheen and have a reduced tubercular carpal spur.[16] The head, neck and breast are black and contrast with the broad white supercilium that runs from over the eye to the back of the neck. The lower back and tail coverts are chestnut. The tail is stubby and reddish brown with black terminal band. The greenish yellow bill has a red-base to the upper mandible. A lappet or frontal shield extends up over the forehead and is reddish purple. The legs are greenish. The toes are long and the straight and the elongated nail on the hind toe is longer than the toe.[17] Downy chicks are light brown with a dark stripe running down the nape.[9][18] Young birds have brown upperparts, a rufous crown, white underparts, a buff foreneck, an undeveloped frontal shield, and may have a dull supercilium.[19] Adults can be confused at a distance with the common moorhen (which is found in similar habitat)[20] and with the watercock and while young can appear similar to the young of the pheasant-tailed jacana, they lack the black necklace seen in that species.[21]

Measurements of 43 males and 25 females from southern India[22]
Measurement (± s.e.) Males Females
mass (g) 176.2 ± 1.68 282.4 ± 5.22
bill (mm) 22.5 ± 0.96 25.1 ± 0.15
shield height (mm) 22.5 ± 0.17 24.1 ± 0.34
wing (mm) 162 ± 0.46 189 ± 1.03
tarsus (mm) 70.2 ± 0.36 78.6 ± 0.60
tail (mm) 45.5 ± 0.47 51.2 ± 0.73

Distribution and habitat

The species is widely distributed across the Indian Subcontinent (but not Sri Lanka or western Pakistan) and Southeast Asia mainly in low elevations. Both this species and the pheasant-tailed jacana can occur in the same habitat. It is sedentary apart from seasonal dispersal in response to drought and rains.[19] They are able to use wetlands covered in introduced weeds such as water hyacinth and make use of the cover provided by Ipomoea aquatica when breeding.[23]

Behaviour and ecology
Downy young
A bare nest on a Victoria amazonica leaf

Bronze-winged jacanas are found singly or in pairs foraging on aquatic vegetation. They balance on their long legs and long toes, and feed on plant material (claimed to be purely incidental[24]), insects and other invertebrates picked from the floating vegetation or the water's surface. Call is a wheezy piping seek-seek-seek given mostly in alarm. When threatened they sometimes hide by submerging themselves. The breeding season starts after the rains (June to September in India but occasional breeding in March rains reported in Rajasthan[25]). Males defend territories from other males with open wing and neck stretched displays which can escalate to pecking.[26] The territory maintenance activities are at a maximum from around 9 to 11 AM.[27] The nest is a small platform of stems and leaves of Pistia, Nymphoides, Hydrilla, and Eichhornia placed on a mat of vegetation but eggs may also be laid directly on the leaf of a lotus plant. The usual clutch is four, the eggs are very conical, glossy brown with irregular black zig-zag markings. Incubation and care of the young is entirely left to males. The eggs hatch in 29 days. Predation rates of eggs are high, up to 94% were lost in one study to various predators including birds and turtles.[22] Young chicks may be sheltered between the wings and carried to safety.[19] They become independent of their father when they are about ten weeks old.[22]

Nematode parasites, Gongylonema indica and Stellocaronema alii[28] and the feather louse Rallicola indicus[29][30] have been described from specimens of the bronze-winged jacana.[31]

A young bird

Mating system

Bronze-winged jacanas, like other jacanas,[32] show a reversal of sex-roles with the female being larger, territorial, polyandrous, and competing with other females to maintain harems of males to incubate their clutches of eggs. Each female's territory encompasses one to four males and their individual territories. Heavier males defend their territories from other males and the degree of polyandry of females is a trade-off based on the sizes of the male territories and the number of males in the harems. Females mate with multiple males, leading to intense sperm competition, and the male that receives (termed as receivers) a clutch of eggs for incubation may destroy clutches in which their paternity is in doubt.[33] In addition to the territorial males, there may be many "floater" males that attempt to copulate with females.[34] Females may copulate more often with receiver males to ensure clutch survival while also copulating with non-receivers to maintain their harem. The fitness cost of clutches destroyed by receivers is much higher than losing males from her harem. Males make a yelling call to gain the attention of females. Males yell more when in larger harems. Females appear to use yells to assess male quality, and copulate with males that yelled more.[35][36]

References
  1. BirdLife International (2012). "Metopidius indicus". IUCN Red List of Threatened Species. 2012. Retrieved 26 November 2013.CS1 maint: ref=harv (link)
  2. Whittingham, L.A.; Sheldon, F.H.; Emlen, S.T. (2000). "Molecular phylogeny of jacanas and its implications for morphologic and biogeographic evolution" (PDF). The Auk. 117 (1): 22–32. doi:10.1093/auk/117.1.22.
  3. Latham, John (1790). Index Ornithologicus, Sive Systema Ornithologiae: Complectens Avium Divisionem In Classes, Ordines, Genera, Species, Ipsarumque Varietates (in Latin). Volume 2. London: Leigh & Sotheby. p. 765.
  4. Peters, James Lee, ed. (1934). Check-list of Birds of the World. Volume 2. Cambridge, Massachusetts: Harvard University Press. p. 228.
  5. Latham, John (1787). Supplement to the General Synopsis of Birds. London: Printed for Leigh & Sotheby. pp. 257–258.
  6. Wagler, Johann Georg (1832). "Mittheilungen über einige merkwürdige Thiere". Isis von Oken (in German). Cols 275-281 [279].
  7. Gill, Frank; Donsker, David, eds. (2019). "Grebes, flamingos, buttonquail, plovers, painted-snipes, jacanas, plains-wanderer, seedsnipes". World Bird List Version 9.2. International Ornithologists' Union. Retrieved 26 June 2019.
  8. Jobling, James A. (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 204, 252. ISBN 978-1-4081-2501-4.
  9. Rasmussen, Pamela C.; Anderton, John C. (2005). Birds of South Asia: the Ripley guide. Volume 2: Attributes and Status (2nd ed.). Washington, D.C.: Smithsonian Institution. p. 150. ISBN 84-87334-67-9.
  10. Forbes, W. A. (1881). "Notes on the anatomy and systematic position of the jaçanás (Parridæ)". Proceedings of the Zoological Society of London. 49: 639–647. doi:10.1111/j.1096-3642.1881.tb01319.x.
  11. Forbes, W.A. (1881). "Notes on the Anatomy and Systematic Position of the Jaçanás (Parridae)". Proceedings of the Zoological Society of London: 645–647.
  12. Fry, C.H. (1983). "The jacanid radius and Microparra, a neotenic genus". Gerfaut. 73: 173–184.
  13. Elliot, D.G. (1888). "The Jacanidæ" (PDF). The Auk. 5 (3): 288–305. JSTOR 4067321.
  14. Fry, C.H. (1983). "The Jacanid radius and microparra, a neotenic genus". Le Gerfaut. 73: 173–184.
  15. Fry, C.H. "Short notes. Incubation, brooding, and a structural character of the African Jacana". Ostrich: Journal of African Ornithology. 54 (3): 172–184. doi:10.1080/00306525.1983.9634467.
  16. Lucas, Frederic A. (1893). "The weapons and wings of birds". Annual Report of the Board of Regents of the Smithsonian Institution. Washington D.C.: Smithsonian Institution. pp. 653–663.
  17. Whistler, Hugh (1949). Popular Handbook of Indian Birds (4 ed.). London: Gurney and Jackson. pp. 456–457.
  18. Ramachandran, N. K.; Vijayan, V.S. (1995). "Breeding ecology of the bronzewinged (Metopidius indicus) and pheasant-tailed (Hydrophasianus chirurgus) jacanas in Keoladeo National Park, Bharatpur, Rajasthan". Journal of the Bombay Natural History Society. 92: 322–334.
  19. Ali, Salim; Ripley, S. Dillon (1980). Handbook of the Birds of India and Pakistan. Volume 2. Megapodes to Crab Plover (2 ed.). Delhi: Oxford University Press. pp. 201–202.
  20. Ramachandran, N. K. (1998). "Interspecific association of jacanas (Hydrophasianus chirurgus and Metopidius indicus) and the role of habitat". Journal of the Bombay Natural History Society. 95: 76–86.
  21. Hayman, Peter; Marchant, John; Prater, A.J. (1988). Shorebirds. Helm. pp. 218–219. ISBN 0-7470-1403-5.
  22. Butchart, S.H.M. (2000). "Population structure and breeding system of the sex-role reversed, polyandrous Bronze-winged Jacana Metopidius indicus". Ibis. 142 (1): 93–102. doi:10.1111/j.1474-919X.2000.tb07688.x.
  23. Ramachandran, N. K.; Vijayan, V. S. (1997). "Population and distribution of Bronzewinged (Metopidius indicus) and Pheasant-Tailed (Hydrophasianus chirurgus) Jacanas in Keoladeo National Park, Bharatpur, Rajasthan". Journal of the Bombay Natural History Society. 94: 307–316.
  24. Jenni, D.A.; Bonan, A. (2019). "Jacanas (Jacanidae)". In del Hoyo, J.; Elliott, A.; Sargatal, J.; Christie, D.A.; de Juana, E. (eds.). Handbook of the Birds of the World Alive. Barcelona: Lynx Edicions. Retrieved 2019-03-26.
  25. Vyas, Rakesh (1995). "Unusual nesting season of Bronzewinged Jacana Metopidius indicus (Latham)". Journal of the Bombay Natural History Society. 92: 119–120.
  26. Mathew, D.N. (1964). "Observations on the breeding habits of the Bronze-winged Jacana (Metopidius indicus (Latham))". Journal of the Bombay Natural History Society. 61: 295–302.
  27. Ramachandran, N. K. (1998). "Activity patterns and time budgets of the pheasant-tailed (Hydrophasianus chirurgus) and bronzewinged (Metopidius indicus) jacanas". Journal of the Bombay Natural History Society. 95: 234–245.
  28. Wong, P.L. (1985). "Revision of the genus Stellocaronema Gilbert, 1930 (Nematoda: Habronematoidea)". Canadian Journal of Zoology. 63 (10): 2430–2436. doi:10.1139/z85-359.
  29. Valim, Michel P. (2009). "Type specimens of lice (Insecta: Phthiraptera) held in the Museu de Zoologia da Universidade de São Paulo, Brazil". Papéis Avulsos de Zoologia (São Paulo). 49 (17). doi:10.1590/S0031-10492009001700001. ISSN 0031-1049.
  30. Emerson, K.C.; Elbel, Robert E. (1961). "A new species of Rallicola (Mallophaga) from Southeast Asia". Entomological News: 130–132.
  31. Cordeiro, Helrik da Costa; Melo, Francisco Tiago de Vasconcelos; Giese, Elane Guerreiro; Santos, Jeannie Nascimento dos (2018). "Gongylonema parasites of rodents: a key to species and new data on Gongylonema neoplasticum". Journal of Parasitology. 104 (1): 51–59. doi:10.1645/17-3. PMID 29135391.
  32. Emlen, S.T.; Wrege, P.H. (2004). "Size dimorphism, intrasexual competition and sexual selection in wattled jacana Jacana jacana, a sex-role-reversed shorebird in Panama". Auk. 121 (2): 391–403. doi:10.1642/0004-8038(2004)121[0391:SDICAS]2.0.CO;2.
  33. Butchart, S.H.M. (1999). "Sexual conflicts and copulation patterns in polyandrous bronze-winged jacanas (Metopidius indicus)". Behaviour. 136 (4): 443–468. doi:10.1163/156853999501414.
  34. Moreno, Juan (2016). "The unknown life of floaters: the hidden face of sexual selection". Ardeola. 63: 49–77. doi:10.13157/arla.63.1.2016.rp3.
  35. Butchart, S.H.M.; Seddon, N.; Ekstrom, J.M.M. (1999). "Yelling for sex: harem males compete for female access in bronze-winged jacanas". Animal Behaviour. 57 (3): 637–646. doi:10.1006/anbe.1998.0985. PMID 10196054.
  36. Butchart, S.H.M.; Seddon, N.; Ekstrom, J.M.M. (1999). "Polyandry and competition for territories in bronze-winged jacanas". Journal of Animal Ecology. 68 (5): 928–939. doi:10.1046/j.1365-2656.1999.00341.x.

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