Identify wild ducks by first determining whether they belong to the dabbler, diving or another category of the species. Then, use the same identifying techniques used for other birds, including physical appearance, habitat and location, songs and calls, and behavior.
Most North American ducks fall into either the dabbler or diving duck categories. Dabblers feed by tipping their bodies into the water, often bottom-up style, to reach food, and for this reason, they often live in more shallow bodies of water. Diving ducks submerge their entire bodies into the water to reach food at the bottom, so you find them on deeper lakes, reservoirs and ponds.
Although they have a similar basic structure, wild ducks vary in physical appearance, especially in color. The wood duck sports several flashy colors, whereas the Gadwall has a more dull, uniform shade. Note that colors may also vary between males and females of the same species.
Most ducks live in a water environment, but some prefer swamps and wetlands. Others make their homes on open bodies of water. Songs and calls also vary, ranging from the croak of the common merganser to the whistling of the northern pintail. Vocalizations are especially useful for identifying ducks in habitats where they are difficult to observe.