Duck is the common name for a number of species in the Anatidae family of birds. The ducks are divided between several subfamilies listed in full in the Anatidae article. Ducks are mostly aquatic birds, mostly smaller than their relatives the swans and geese, and may be found in both fresh water and sea water.
Most ducks have a wide flat beak adapted for dredging. They
exploit a variety of food sources such as grasses, aquatic
plants, fish, insects, small amphibians, worms, and small
Ducks are sometimes confused with several types of unrelated water birds with similar forms, such as loons or divers, grebes, gallinules, and coots.
Many species of ducks are temporarily flightless while moulting; they seek out protected habitat with good food supplies during this period. This moult typically precedes migration.
Some duck species, mainly those breeding in the temperate and Arctic Northern Hemisphere, are migratory, but others, particularly in the tropics, are 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.
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. They have along the inside of the beak 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 large fish.
The males (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.
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 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. Nests may also 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.
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".
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.
Foie gras is often made using the liver of domestic ducks, rather than of geese.
In a wildlife pond, the bottom over most of the area should be too deep for dabbling wild ducks to reach the bottom, to protect bottom-living life from being constantly disturbed and eaten by wild ducks dredging, and domestic ducks should not be allowed in.
Despite widespread misconceptions, most ducks other than female Mallards and domestic ducks do not "quack"; for example, the scaup makes a noise like "scaup", whence its name.
A common urban legend says that quacks do not echo, however this has been shown to be false
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.
FAO reports that China is the top duck market in 2004 followed by Vietnam and other South East Asian countries.
This Duck Page is Copyright The Animal Web Guide © 2004 - 2009 Chuck Ayoub