Editing Comb duck (section)

==Description==
This common species is unmistakable. It is one of the largest species of duck. Length can range from {{convert|56|to|76|cm|in|abbr=on}}, wingspan ranges from {{convert|116|to|145|cm|in|abbr=on}} and weight from {{convert|1.03|to|2.9|kg|lb|abbr=on}}.<ref>Ogilvie & Young, ''Wildfowl of the World''. New Holland Publishers (2004), {{ISBN|978-1-84330-328-2}}</ref><ref>{{cite book|author=Hilty, Steven L. |title=Birds of Venezuela|url=https://books.google.com/books?id=40mFwoALUFUC&pg=PA197|year= 2002|publisher=Princeton University Press|isbn=978-1-4008-3409-9|pages=197–}}</ref><ref>[http://www.biodiversityexplorer.org/birds/anatidae/sarkidiornis_melanotos.htm ''Sarkidiornis melanotos'' (Comb duck, Knob-billed duck)] {{Webarchive|url=https://web.archive.org/web/20120414193101/http://www.biodiversityexplorer.org/birds/anatidae/sarkidiornis_melanotos.htm |date=2012-04-14 }}. biodiversityexplorer.org</ref> Adults have a white head freckled with dark spots, and a pure white neck and underparts. The upperparts are glossy blue-black upperparts, with bluish and greenish [[iridescence]] especially prominent on the secondaries (lower arm feathers). The male is much larger than the female, and has a large black knob on the [[beak|bill]].

If seen at a distance, immature comb ducks can also be mistaken for a [[fulvous whistling duck]] (''Dendrocygna bicolor''). However, knob-billed ducks in immature [[plumage]] are rarely seen without adults nearby and thus they are usually easily identified, too.<ref name = mb1987/>