The two major duck groups, puddle and diving ducks, differ in several ways. Divers inhabit large deep lakes and rivers, and coastal bays and inlets; puddle ducks tend to stick to the shallows of lakes, rivers and freshwater marshes, although they frequent saltwater, especially during migration. Diving ducks are, as their name implies, adept at diving and obtain most of their food this way. Puddle ducks prefer to feed on the surface or close to it; often they stretch their heads underwater, feeding upended with their tails in the air. As a group, they are not accomplished divers, but adults dive occasionally and ducklings do so frequently.
Puddle ducks feed in the water along the fringes of islands and shorelines and on dry land. Their diet consists mainly of vegetable matter -- seeds, grasses, leaves and stems of underwater plants, agricultural crops, nuts -- along with mollusks, insects and fish.
These shallow-water ducks ride higher in the water than their diving cousins, and launch themselves directly upward when taking off; they do not need to run across the water to build up speed for takeoff as diving ducks do. Puddle ducks are excellent swimmers, sure-footed on land, and swift agile fliers. On the wing, they often display a speculum, or wing patch -- a bright, iridescent panel of feathering close to the body on the trailing edge of each wing. Speculum color varies from species to species and may function as a flashing signal to help keep a flock together. To the human observer, the speculum is often a telltale field mark.
By Chuck Fergus
