|Black-necked Swan (Cygnus melancoryphus)|
|The Black-necked Swan is closely related to both the Mute Swan (Cygnus olor) of the northern hemisphere and the Black Swan (Cygnus atratus) of Australasia. It is found in southern South America, both Chile and Argentina and is partially migratory with some birds wintering in Paraguay and southern Brazil.|
|It lives in swamps, marshes, shallow lakes and on the coast. It is primarily vegetarian but also eats algae, insects and maybe fish spawn.
Photo 7 shows an immature bird.
There is an illustration in HBW, Volume 1, Pages 565 and 574.