Does my male duck need a female companion?
Does my female duck need a male companion?
Female ducks do fine with only female companions. Male ducks do fine with only male companions. In fact, they tend to be easier to manage and less aggressive when there are no females to fight over. Ducks do not need a companion of the opposite sex to be happy. All ducks DO need a companion of some sort, however. Ducks are social creatures and need company.
The one combination that does not work is multiple male ducks with only one female. This will lead to fighting, and most likely, the female will be killed. Neither will it work to have an equal number of males and females if there are more than one of each. They will still fight far too much. The ratio must be at LEAST three females to one drake. In Muscovies, the ratio is much higher, at least eight females per drake. One drake can service about 8-15 ducks.
But ducks will certainly also be happy in couples.