The mallard, wood duck, green-winged teal, northern shoveler and black-bellied whistling duck are some of the over 25 species of ducks living in North America. Ducks belong to different categories based on shared features such as feeding habits and habitat. Dabblers, diving ducks and sea ducks are three such categories.
Dabblers usually feed by tipping their bodies into the water, causing their rear ends to point upwards as their mouths take in food just under the water's surface. Because of this particular feeding habit, dabblers often spend their time in the shallows of bodies of water. Examples of dabbler ducks include the American black duck, the white-cheeked pintail, the northern pintail, the masked duck and the gadwall.
By contrast, diving ducks, as their name implies, often dive all the way into the water to pursue their food. The harlequin duck perhaps most clearly epitomizes this group's name, as it will dive to the bottom of even rapidly moving streams and rivers in search of food. Other ducks in this category are the ruddy duck, canvasback, tufted duck and ring-necked duck. Sea ducks is a subcategory of diving ducks, and comprises those diving ducks (including the bufflehead and long-tailed duck) that inhabit sea environments.