Indian spot-billed duck: Difference between revisions

[[File:Davidraju IMG 3845.jpg|thumb|left|Characteristic green speculum with white base and white tertials]]

[[File:Indian Spot-billed Duck Karanji Mysore Dec23 A7C 08345.jpg|thumb|left|Male with red spot at the base of bill]]

This duck is around the same size as a [[mallard]] and has a scaly patterned body with a green [[speculum feathers|speculum]] bordered by white. At rest the white stripe stands out and the long neck and the bill with yellow tip and orange red spots at the base are distinctive in the nominate subspecies. In flight it is distinguished by the green [[Speculum feathers|speculum]] with a broad white band at the base. The red spots at the base of the bills are absent in ''haringtoni''. It measures {{convert|55|-|63|cm|in|abbr=on}} in length and {{convert|83|-|95|cm|in|abbr=on}} across the wings, with a body mass of {{convert|790|-|1500|g|lb|abbr=on}}.<ref name = "CRC">{{cite book|title=CRC Handbook of Avian Body Masses|first= John B. |last=Dunning Jr. |publisher=CRC Press |year=1992|isbn=978-0-8493-4258-5}}</ref><ref>{{Cite book|pages=219–220|title=Wildfowl| author=Madge, Steve|publisher=A&C Black| year=2010}}</ref> These are mainly grey ducks with a paler head and neck and a black [[beak|bill]] tipped bright yellow. The wings are whitish with black flight feathers below, and from above show a white-bordered green The male has a red spot on the base of the bill, which is absent or inconspicuous in the smaller but otherwise similar female. The male does not have an [[Plumage#Eclipse plumage|eclipse plumage]]. The legs and feet are bright orange to coral red. Juveniles are browner and duller than adults.<ref name=hbk>{{cite book|pages=157–160|title=Handbook of the Birds of India and Pakistan. Volume 1.|author=Ali, Salim|author2=S. Dillon Ripley|name-list-style=amp|year=1978|edition=2nd|publisher=Oxford University Press|place=New Delhi}}</ref>

 

 

==Distribution ==

This [[duck]] is a resident throughout [[Pakistan]] and [[India]] in freshwater wetlands. They tend to avoid very large patches of open water and prefer medium-sized wetlands with vegetation cover. Some individuals may however migrate as a bird ringed at Bharatpur in Rajasthan on 5 December 1969 was recovered near Novosibirsk in August 1970.<ref name=hbk /><ref>{{cite journal| author=Somane, Shailaja S |year=1971| title= Recovery of a Spotbill Duck (''Anas poecilorhyncha'') in U.S.S.R. |journal=J. Bombay Nat. Hist. Soc.|volume= 68|issue=1|pages= 244–246|url= https://www.biodiversitylibrary.org/page/48430404}}</ref> It is quite gregarious outside the breeding season and forms small flocks. The northernmost populations have expanded their range northwards by more than 500&nbsp;km since the early 20th century, possibly in reaction to [[global warming]].<ref name=kul>{{Cite journal| doi = 10.1642/0004-8038(2004)121[0930:AHASGF]2.0.CO;2| issn = 0004-8038

| volume = 121| issue = 3| pages = 930| last = Kulikova| first = Irina V.

==Biology==

It is a bird of freshwater [[lake]]s and [[marsh]]es in fairly open country and feeds by dabbling for plant food mainly in the evening or at night. The breeding season varies with rainfall and water condition but is July to September in northern India and November to December in southern India. Multiple broods may be raised.<ref>{{cite journal|author=Trench,C.G.C. |year=1927| title= The breeding of the Spotbill Duck ''Anas poecilorhyncha''.| journal=J. Bombay Nat. Hist. Soc. |volume=32|issue=1|page= 221|url=https://www.biodiversitylibrary.org/page/47859474}}</ref> It nests on the ground hidden in vegetation near water, and lays 8-14 [[bird egg|eggs]]. Nests have sometimes been seen on tree branches covered by creepers.<ref>{{cite journal|author= Dharmakumarsinhji, R.S.|year= 1977| title= Spotbill Duck (''Anas p. poecilorhyncha'') Forster nesting in a tree. |journal=J. Bombay Nat. Hist. Soc. |volume=74|issue=2| pages= 354–355|url= https://www.biodiversitylibrary.org/page/48239125}}</ref> Incubation begins after the last egg is laid (allowing the chicks to hatch simultaneously) and the young hatch after about 24 days. The chicks are black with a yellow back and resemble those of mallards but with a wider eyestripe.<ref name=hbk />

 

Both the male and female have [[bird call|calls]] similar to that of the [[mallard]]. Mallards and eastern spot-billed ducks have been known to hybridize in the wild in eastern Russia and their genetic closeness has been examined in many studies.<ref>{{Cite journal|last1=Kulikova|first1=I. V.|last2=Chelomina|first2=G. N.|last3=Zhuravlev|first3=Yu N.|date=2003-10-01|title=Low Genetic Differentiation of and Close Evolutionary Relationships between Anas platyrhynchos and Anas poecilorhyncha: RAPD–PCR Evidence|journal=Russian Journal of Genetics|language=en|volume=39|issue=10|pages=1143–1151|doi=10.1023/a:1026174910872|s2cid=23832801|issn=1022-7954}}</ref><ref>{{Cite journal|last1=Zhou|first1=Wenliang|last2=Zhang|first2=Chenling|last3=Pan|first3=Tao|last4=Yan|first4=Liangheng|last5=Hu|first5=Chaochao|last6=Xue|first6=Chun|last7=Chang|first7=Qing|last8=Zhang|first8=Baowei|date=2015-03-04|title=The complete mitochondrial genome of Anas poecilorhyncha (Anatidae: Anas)|journal=Mitochondrial DNA|volume=26|issue=2|pages=265–266|doi=10.3109/19401736.2013.823191|pmid=24021013|s2cid=37147471|issn=1940-1736}}</ref> Indian spot-billed ducks feed on plants, including crops such as rice, as well as invertebrates including snails. Through snails such as ''Lymnaea luteola'', they also get infected by cercarian trematodes such as ''Echinoparyphium bagulai.'' Adult trematodes emerge from the duck after about 21 days.<ref>{{Cite journal|last=Jain|first=G. P.|date=1961|title=On a new trematode Echinoparyphium bagulai sp.nov., (Echinostomatidae) from Anas poecilorhyncha|url=https://www.cambridge.org/core/journals/parasitology/article/on-a-new-trematode-echinoparyphium-bagulai-spnov-echinostomatidae-from-anas-poecilorhyncha/8BF4F1D784816FA031AF352BDD1ECA19|journal=Parasitology|volume=51|issue=1–2|pages=123–126|doi=10.1017/s0031182000068542|pmid=13789208|s2cid=6430830 |issn=1469-8161}}</ref> Other trematodes recorded in the species include ''Psilochasmus oxyurus''<ref>{{Cite journal|last=Singh|first=Kunwar Suresh|date=1954|title=Some Trematodes Collected in India|jstor=3223758|journal=Transactions of the American Microscopical Society|volume=73|issue=2|pages=202–210|doi=10.2307/3223758}}</ref> while helminths include ''Opisthorchis obsequens'', ''Notocotylus babai'', ''N. linearis'', ''Echinoparyphium clerci'', ''Amidostomum skrjabini'', and ''Hymenolepis wardlei''.<ref>{{cite journal|author1=Dubey, J.P.|author2=Pande, B.P.|year=1964|title=A note on some helminths of the wild duck (Anas poecilorhyncha)|journal=Indian Journal of Helminthology|volume=16|issue=1|pages=27–32}}</ref><ref>{{cite book|url=https://archive.org/stream/popularhandbooko033226mbp#page/n575/mode/2up|pages=527–528| title=Popular handbook of Indian Birds| author=Whistler, Hugh |edition=4| publisher=Gurney and Jackson| year=1949}}</ref>

 

They are seen isolated from other species and usually in pairs or small groups and when disturbed they can take off easily and nearly vertically from the water. They were hunted extensively in British India, noted for their excellent taste. When shot at, especially when in moult, they are known to dive and remain underwater to evade capture. A local name for it was "gheret-pai"<ref>{{cite book|url=https://archive.org/stream/baburnamainengli02babuuoft#page/500/mode/1up|title=The Babur-nama in English (Memoirs of Babur). Volume II|author=Beveridge, A.S.|year=1922|page=500|publisher=London, Luzac}}</ref> or "garam-pai".<ref>{{Cite journal|author=Ali, Salim|year=1927|title=The Moghul Emperors of India as Naturalists and Sportsmen. Part II.|url=https://archive.org/stream/journalofbomb32121927bomb#page/63/mode/1up|journal=J. Bombay Nat. Hist. Soc.|volume=32|issue=1|pages=34–63}}</ref> In southern India, a method of hunting involved using floating bundles of rushes on which the hunters lay in wait.<ref>{{cite book|pages=133–139|url= https://archive.org/stream/indianduckstheir00bake#page/n175/mode/2up| title=Indian Ducks and their Allies|author=Baker, E.C. Stuart| year=1908|publisher=Bombay Natural History Society}}</ref> Natural predators of the ducks include birds of prey and terrestrial predators including pythons and otters.<ref>{{cite journal|author1=Sridharan, U.|author2= Manohar, B.R. |year=1985| title= A note on the Asiatic Rock Python ''Python molurus'' feeding on the Spotbill Duck ''Anas poecilorhyncha''. |journal=J. Bombay Nat. Hist. Soc. |volume=81| pages= 710–711|url= https://www.biodiversitylibrary.org/page/48874676}}</ref><ref>{{cite book|url=https://archive.org/stream/naturalhistoryof02phil#page/n137/mode/2up|title=A natural history of the ducks. Volume II|author=Phillips, John C.|publisher=Houghton Mifflin|year=1923|place=Boston and New York|pages=90–96}}</ref>

==References==

{{Commons category|Anas poecilorhyncha}}