Editing Duck (section)

==Morphology==
[[File:Mandarin.duck.arp.jpg|thumb|Male [[Mandarin duck]]]]{{Unreferenced section|date=October 2024}}
The overall [[body plan]] of ducks is elongated and broad, and they are also relatively long-necked, albeit not as long-necked as the geese and swans. The body shape of diving ducks varies somewhat from this in being more rounded. The [[Beak|bill]] is usually broad and contains serrated [[pecten (biology)|pectens]], which are particularly well defined in the filter-feeding species. In the case of some fishing species the bill is long and strongly serrated. The scaled legs are strong and well developed, and generally set far back on the body, more so in the highly aquatic species, which typically feature [[Webbed foot|webbed feet]]. The wings are very strong and are generally short and pointed, and the [[bird flight|flight]] of ducks requires fast continuous strokes, requiring in turn strong wing muscles. Three species of [[steamer duck]] are almost flightless, however. Many species of duck are temporarily flightless while [[moult]]ing; they seek out protected habitat with good food supplies during this period. This moult typically precedes [[bird migration|migration]].

The drakes of northern species often have extravagant [[plumage]], but that is [[moult]]ed in summer to give a more female-like appearance, the "eclipse" plumage. Southern resident species typically show less [[sexual dimorphism]], although there are exceptions such as the [[paradise shelduck]] of [[New Zealand]], which is both strikingly sexually dimorphic and in which the female's plumage is brighter than that of the male. The plumage of juvenile birds generally resembles that of the female. Female ducks have evolved to have a corkscrew shaped vagina to prevent forced copulations.