Duck once meant diver, replacing an older word for the bird
Duck names many Anatidae waterfowl smaller and shorter-necked than geese or swans, yet the label is a form taxon, not one clean clade. Old English dūce, “diver,” from a verb meaning to bend low, replaced earlier ened—still echoed in Dutch eend and German Ente.
Loons, grebes, and coots look similar but sit outside the duck group. Young downy birds are ducklings; markets sometimes sell tender young domestics under that label. Males are drakes; females are ducks or hens in ornithology. The old word ened came down from Proto-Indo-European, kin to Latin anas and Sanskrit ātí, and may have been dropped because it sounded too much like ende, end.
All belong to Anseriformes with geese, swans, screamers, and the magpie goose; most join Anatidae. “True ducks” in Anatinae include dabbling Anatini that tip up to feed at freshwater surfaces. Other tribes cover diving ducks, fish-and-shellfish-eating sea ducks, and stiff-tailed stifftails, while whistling ducks, shelducks and Australia's freckled duck get shuffled between groups; taxonomists propose anywhere from two to five duck subfamilies, and frequent hybridisation muddies the picture.
Ducks live on every continent except Antarctica, even on subantarctic South Georgia and remote islands such as Hawaii and the Galápagos. Northern breeders often migrate, tropical ones mostly do not, and some Australian species wander to pools left by sudden rain. A comb-like pecten along the bill strains food and helps with preening; divers are heavier, which makes take-off harder, and mergansers swallow large fish. Northern drakes moult their showy feathers in summer into a drab eclipse plumage. Most pairs last a single season, though larger and sedentary species may bond for years. The Guardian has warned that bread harms ducks and fouls waterways.
Source: Duck
