Mandarin Ducks (Aix galericulata)by Roland zh, : Because the male and female plumages of the Mandarin Duck are so unalike, yuan-yang is frequently used colloquially in Cantonese to mean an &quot;odd couple&quot; or &quot;unlikely pair&quot; http://en.wikipedia.org/wiki/Mandarin_Duck #Ducks #Mandarin_Duck