Female ducks are known as either hens or ducks, while male ducks are known as drakes and their young are known as ducklings. In numerous duck species, females have less colourful plumage than males, making them easier to distinguish.
Additionally, hens and drakes can be distinguished by the sounds they produce. Only hens make the quacking sound commonly associated with ducks. Drakes typically produce a quieter sound that resembles a whistle or a whisper.
Almost always, ducks with upwardly curled tail feathers are drakes; exceptions may arise if there is no male and a hen assumes the drake role. Immediately after the mating season, both drakes and hens begin moulting and are unable to fly for several months. During this phase, it is difficult to distinguish the two sexes visually; sound is the most reliable indicator.