Ducks are sometimes confused with several types of unrelated water birds with similar forms, such as loons or divers, grebes, gallinules, and coots.
The word duck (from Anglo-Saxon d?ce), meaning the bird, came from the verb "to duck" (from Anglo-Saxon supposed *d?can) meaning "to bend down low as if to get under something" or "to dive", because of the way many species in the dabbling duck group feed by upending (compare Dutch duiken, German tauchen = "to dive").
This happened because the older Anglo-Saxon words ened (= "duck") and ende (= "end") came to be pronounced the same: other Germanic languages still have similar words for "duck" and "end": for example, Dutch eend = "duck", eind = "end", German ente = "duck", ende = "end"; this similarity goes back to Indo-European: compare Latin anas (stem anat-) = "duck", Lithuanian antis = "duck", Ancient Greek ?????, ????? (n?ssa, n?tta) = "duck"; Sanskrit anta = "end".
Some people use "duck" specifically for adult females and "drake" for adult males, for the species described here; others use "hen" and "drake", respectively.
A duckling is a young duck in downy plumage or baby duck.; but in the food trade young adult ducks ready for roasting are sometimes labelled "duckling".
Many species of duck are temporarily flightless while moulting; they seek out protected habitat with good food supplies during this period. This moult typically precedes migration.
The drakes of northern species often have extravagant plumage, but that is moulted in summer to give a more female-like appearance, the "eclipse" plumage. Southern resident species typically show less sexual dimorphism.
Most ducks have a wide flat beak adapted for dredging.
Ducks exploit a variety of food sources such as grasses, aquatic plants, fish, insects, small amphibians, worms, and small molluscs.
Diving ducks and sea ducks forage deep underwater. To be able to submerge more easily, the diving ducks are heavier than dabbling ducks, and therefore have more difficulty taking off to fly.
Dabbling ducks feed on the surface of water or on land, or as deep as they can reach by up-ending without completely submerging. Along the inside of the beak they have tiny rows of plates called lamellae like a whale's baleen. These let them filter water out of the side of their beaks and keep food inside.
A few specialized species such as the smew, goosander, and the mergansers are adapted to catch and swallow large fish.
Despite widespread misconceptions, most ducks other than female Mallards and domestic ducks do not "quack"; for example, the scaup makes a noise like "scaup", which its name came from.
A common urban legend claims that duck quacks do not echo; however, this has been shown to be false. This myth was first debunked by the Acoustics Research Centre at the University of Salford in 2003 as part of the British Association's Festival of Science. It was also debunked in one of the earlier episodes of the popular Discovery Channel television show MythBusters.
Some duck species, mainly those breeding in the temperate and Arctic Northern Hemisphere, are migratory; those in the tropics, however, are generally not. Some ducks, particularly in Australia where rainfall is patchy and erratic, are nomadic, seeking out the temporary lakes and pools that form after localised heavy rain.
Ducks have become an accepted presence in populated areas. Migration patterns have changed such that many species remain in an area during the winter months. In spring and early summer ducks sometimes influence human activity through their nesting; sometimes a duck pair nests well away from water, needing a long trek to water for the hatchlings: this sometimes causes an urgent wildlife rescue operation (e.g. by the RSPCA) if the duck nested somewhere unsuitable like in a small enclosed courtyard.
A worldwide group like the ducks has many predators. Ducklings are particularly vulnerable, since their inability to fly makes them easy prey not only for avian hunters but also large fish like pike, crocodilians, and other aquatic hunters, including fish-eating birds such as herons. Ducks' nests may be raided by land-based predators, and brooding females may sometimes be caught unaware on the nest by mammals (e.g. foxes) and large birds, including hawks and eagles.
Adult ducks are fast fliers, but may be caught on the water by large aquatic predators. This can occasionally include fish such as the muskie in North America or the pike in Europe. In flight, ducks are safe from all but a few predators such as humans and the Peregrine Falcon, which regularly uses its speed and strength to catch ducks.
As food, "duck" refers to the meat of several species of bird in the Anatidae family, found in both fresh and salt water. Duck is eaten in many cuisines around the world.
Ducks have many economic uses, being farmed for their meat, eggs, feathers, (particularly their down). They are also kept and bred by aviculturists and often displayed in zoos. All domestic ducks are descended from the wild Mallard Anas platyrhynchos, except the Muscovy Duck . Many domestic breeds have become much larger than their wild ancestor, with a "hull length" (from base of neck to base of tail) of 30 cm (12 inches) or more and routinely able to swallow an adult British Common Frog Rana temporaria whole.
FAO reports that China is the top duck market in 2004 followed by Vietnam and other South East Asian countries.
In many areas, wild ducks of various species (including ducks farmed and released into the wild) are hunted for food or sport, by shooting, or formerly by decoys. From this came the expression "a sitting duck", which means "an easy target".
In 2002, psychologist Richard Wiseman and colleagues at the University of Hertfordshire (UK) finished a year-long LaughLab experiment, concluding that, of the animals in the world, the duck is the type that attracts most humor and silliness; he said "If you're going to tell a joke involving an animal, make it a duck." The word "duck" may have become an inherently funny word in many languages because ducks are seen as a silly animal, and their odd appearance compared to other birds. Of the many ducks in fiction, many are silly cartoon characters like Daffy Duck (see the New Scientist article mentioning humor in the word "duck").
A duck test is a form of inductive reasoning, which can be phrased as follows: "If a bird looks like a duck, swims like a duck and quacks like a duck, then it probably is a duck." The test implies that a person can figure out the true nature of an unknown subject by observing this subject's readily identifiable traits. It is sometimes used to counter abstruse arguments that something is not what it appears to be.
Male Wood Duck in eclipse plumage
