Duck

Duck is the ordinary name for a number of species in the Anatidae family of birds. The ducks are divided between numerous subfamilies listed in full in the Anatidae article. Ducks are mostly aquatic birds, mostly lesser 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 develop a variety of food sources such as grasses, aquatic plants, fish, insects, small amphibians, worms, and small mollusks. Diving ducks and sea ducks scavenge deep underwater; dabbling ducks feed on the surface of water or on land. Dabbling ducks have in their beaks particular plates called lamellae alike to a whale's baleen. These tiny rows of plates along the inside of the beak let them filter water out of the side of their beaks and keep food inside. To be able to submerge more easily, the diving ducks are heavier than dabbling ducks, and therefore have more difficulty taking off to fly. A few particular species such as the Smew, Goosander, and the mergansers) are adapted to catch large fish.

The males (drakes) of northern species often have profligate plumage, but that is molted in summer to give an additional female-like appearance, the "eclipse" plumage. Southern resident species classically show less sexual dimorphism. Many species of ducks are temporarily flightless while molting; they seek out protected habitat with good food supplies during this period. This molt naturally precedes migration.

Some duck species, mainly those breeding in the temperate and arctic Northern Hemisphere, are migratory, but others, mainly in the tropics, are not. Some ducks, particularly in Australia where rainfall is patchy and erratic, are nomadic, seeking out the provisional lakes and pools that form after localized heavy rain.

Some people use "duck" especially for adult females and "drake" for adult males, for the species described here; others use "hen" and "drake", respectively.

Ducks are sometimes puzzled with several types of unrelated water birds with parallel forms, such as loons or divers, grebes, gallinules, and coots.

A worldwide group like the ducks has lots of predators. Ducklings are mainly vulnerable, since their inability to fly makes them easy prey not only for avian hunters but also huge 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 wedged 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 huge aquatic predators. This can irregularly include fish such as the muskie in North America or the pike in Europe. In flight, ducks are secure from all but a few predators, although the Peregrine Falcon regularly uses its speed and power to catch ducks.