Separating the Ducks
Ducks are often classified by their diving abilities, for there are dabbling ducks and diving ducks. Dabblers, or pond ducks, like to feed on or near the surface of shallow water, while diving ducks submerge themselves in water, sometimes to a great depth.
The Divers
Diving ducks swim underwater to obtain their food. Many of these ducks feed on small fish, but their diet can also contain shellfish, mollusks and aquatic plants. Diving ducks rarely make it to the sportsman's dinner table, except perhaps in the case of the canvasback and redheads, which like to feed on eel grass.
Puddle Ducks
Also called dabblers, these ducks are capable of diving, but often prefer to feed by sticking their tail end above the water and stretching their necks downward. This allows them to grab food from the bottom of shallow water. Their diet mostly consists of vegetable matter, making them highly desirable as a meat dish. Domestic ducks fall into this category, except they are usually fed grain instead of foraging on aquatic plants.