Hobbies And Interests
Physical Characteristics
Though they vary in size and shape, most waterfowl have large bodies with relatively long necks and broad, flat bills. Their bills have distinctive features, including a nail at the end for hooking and moving food, and lamillae, comb-like teeth that filter food from water and mud. Waterfowl have short legs, each with three, forward-pointing toes and webbing in between, making them excellent swimmers. With the exception of a handful of species, the birds are strong fliers. To enable flight and protect them from the elements, waterfowl are covered in three types of feathers: contour, the protective outer shell; down, the inner insulating layer commonly used in pillows; and flight, which help provide lift and forward propulsion during flight. The color and pattern of these feathers, or plumage, is unique to each species. All waterfowl have an oil gland at the base of their tail, the uropygial gland, that secretes fluid to keep feathers soft and preserve structure. Birds preen to distribute the oil across their feathers, legs and feet.
Migratory Behavior
Many North American waterfowl species are migratory, breeding and rearing young in northern latitudes and wintering in more southern climates. These semi-annual migrations occur along specific routes, or flyways. In the United States, waterfowl use one of four recognized flyways: the Atlantic, Central, Mississippi or Pacific. The birds often cover great distances, utilizing a number of mechanisms to navigate, including polarized light, landmarks and even a stellar map, as well as non-visual cues like magnetic field and homing. In preparation for the fall migration, waterfowl synchronously molt, losing and replacing all of their feathers. Soon thereafter, the birds journey hundreds if not thousands of miles to destinations where temperatures are more tolerable and food is more plentiful. In these wintering grounds, they accumulate fat for the spring migration north, where they will breed and raise their young.
Mating and Breeding
Mating systems vary by waterfowl species, and include short-term and long-term monogamy, and to a lesser extent, polygamy. Just over 40 percent of all waterfowl species, geese and swans exclusively, pair bond for life. Most ducks form seasonal monogamous bonds. During courtship, often in the fall, males or drakes exhibit their most colorful "breeding" plumage, an adaptation for attracting the more drab-colored females, or hens. On the spring breeding grounds, the pair will nest near wetlands, on the ground or in tree holes or other cavities. The nest is often lined with the hen's down, pulled primarily from the front of her chest. The bare patch, or brood patch, allows for the transfer of heat from her body to the eggs. Clutch sizes are generally large, from four to 16 eggs, with incubation times varying from 22 to 40 days. The drakes of many species depart after the female nests, or soon thereafter. The young waterfowl require 50 to 70 days to reach flight status, a time when they are heavily susceptible to predation.
Habitat and Conservation
Waterfowl depend heavily on two habitat types: wetlands, invaluable through the species' life cycle, and grasslands, critical nesting habitat. Both habitat types are threatened by a number of human and human-influenced activities, including conversion to agriculture and climate change. According to Duck's Unlimited, since European settlement, 53 percent of the original 221 million acres of wetlands have been destroyed--a loss rate of 60 acres per hour.
In response to significant declines in waterfowl populations, and in recognition of the migratory nature of most of waterfowl species, the governments of the United States, Canada and Mexico have coordinated efforts to conserve waterfowl populations and to protect their vital habitat. Each year, the United States Fish &Wildlife Service surveys waterfowl populations and habitat conditions to inform hunting regulations and bag limits. American journalist Walter Cronkite once said, "The perils of duck hunting are great--especially for the duck." Ironically, hunters, under the auspices of Ducks Unlimited, have led the charge in conserving North American waterfowl, protecting 12 million acres of habitat since 1937.