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DUCKS
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Duck
Duck, name
collectively applied to numerous species of a family of waterfowl. Ducks
differ from geese and swans of the same family by their shorter necks
and legs and other anatomical differences. Ducks inhabit all continents
except Antarctica, and most of the world's islands. The legs of most
ducks are placed far apart and toward the rear, making them awkward
walkers but efficient swimmers. The underplumage, or down, which is
buoyant and insulating, is kept water-resistant by frequent preening
with oil from a gland, called the uropygial or preen gland, at the base
of the tail feathers. Ducks, with the exception of mergansers (see
Merganser), have spatulate bills lined with bony notches, or lamellae,
for straining plant and animal matter from water.
Some island species have lost the power
of flight, but most ducks of northern continents are highly migratory.
In a few species, the sexes are alike in color, but in most the males
are brighter and more boldly patterned.
DOMESTIC DUCKS
All except one breed of domestic duck are derived from the mallard,
originally tamed in Eurasia. The exception is the muscovy duck, a large
species of the American tropics. Wild muscovies are mostly black, but
the commonest domestic variety is white, with knobby, naked red skin
around the face and bill. It and the turkey are the only domestic birds
that originated in the Americas.
MIGRATION
Distances covered by migrating ducks vary with the species. One arctic
duck, the spectacled eider, winters at sea off Alaska. Long-distance
champion among American ducks is the blue-winged teal, which nests in
most of North America and winters from the southern United States to
Argentina.
KINDS OF DUCKS
Experts disagree about the classification of ducks into subfamilies and
tribes, but the hundred or so species include a number of obvious
groups. Most familiar are the dabbling or surface-feeding ducks, which
include the mallard, ancestor of most domestic ducks. Members of this
group live primarily on fresh water, where they glean plants and small
aquatic animals from the surface or from shallow bottoms that they can
reach without diving. The pochards, including the canvasback, nest on
fresh water, but winter, often in very large flocks, both on inland
lakes and along the coasts; they feed by diving. Another group of diving
ducks, including the goldeneyes and the bufflehead, nest in tree holes.
The mergansers are specialized for catching fish; the edges of their
bills have sharp, toothlike serrations for holding slippery prey. Most
marine of the North American ducks are the eiders and scoters, which
nest in the far north and winter predominantly at sea.
COURTSHIP AND REPRODUCTION
Ducks have elaborate courtship displays, each unique to its species.
Pair formation in most northern-hemisphere ducks takes place in winter:
hence, unlike most birds with seasonal plumage, males wear their bright
plumage in winter, and briefly assume a female like "eclipse"
plumage during the summer. Nests of most species are on the ground,
containing from 4 to 12 eggs, surrounded by down feathers plucked from
the female's breast and belly. Ducklings are able to swim and feed
themselves soon after they hatch. Some species, such as the wood duck of
North America, nest in holes in trees and will accept artificial nest
boxes. Their ducklings can jump from their nests without injury, and
take to the water soon afterwards.
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