Nature Bulletin No. 692   November 3, 1962
Forest Preserve District of Cook County
Seymour Simon, President
Roberts Mann, Conservation Editor

****:DIPPER DUCKS AND DIVING DUCKS

Almost all of the wild ducks native in North America fall naturally into 
two groups: the Surface-Feeding Ducks and the Diving Ducks. In 
addition there are three species of Mergansers or fish ducks, the unique 
little Ruddy Duck and, in Mexico, two long-legged, long-necked kinds 
misnamed Tree Ducks.

The surface-feeding species seldom dive, even to escape danger. When 
alarmed they spring from the water with a strong upward bound and are 
gone. They prefer ponds, sloughs and rivers where, in shallow water, 
they can scoop up food with their broad strainer-like bills that have fine 
comb-like fringes along the edges, or up-end themselves and, with their 
tails in the air, dabble for it on the bottom. Consequently they are 
commonly called "dipper ducks", "dabblers", or "puddle ducks. "

This group includes many of the most brilliantly colored ducks and they 
are characterized by a distinctively colored and usually iridescent patch 
of feathers, called the speculum, in the middle of each wing. On diving 
ducks the speculum, if any, is usually white or gray. With few 
exceptions the surface-feeding ducks are more palatable and sought by 
hunters because more than half of their feed is vegetable matter. They 
also eat many insects and variable amounts of mollusks, crustaceans 
and small fish.

The principal species are the common mallard, black duck, pintail, 
baldpate or American widgeon, gadwall, blue-winged teal, green-
winged teal, cinnamon teal, the shoveller or spoonbill, and the wood 
duck -- most beautiful of our wildfowl.

There are 43 kinds of diving ducks and most of them occur regularly in 
North America. Some are primarily sea ducks and several nest in Arctic 
regions. Unlike the surface-feeding ducks they get their food by diving 
for it -- sometimes at considerable depths. Consequently, inland, they 
frequent large deep bodies of water rather than sloughs, ponds and 
marshes. A few are chiefly vegetarians but, generally, their food 
includes much less vegetable matter and in many cases consists mainly 
of shellfish such as clams and mussels, crabs and other crustaceans, sea 
urchins, fish eggs and fish -- food which causes their flesh to be less 
palatable than that of surf ace-feeding species . They taste fishy.

A diving duck has shorter legs, located farther back on the body, and 
larger feet distinguished by a big hind toe with a pronounced flap or 
lobe. These adaptations cause them to be more awkward on land but 
increase their ability to dive and swim rapidly. Instead of springing 
upward from the water, most of them patter along the surface for some 
distance, like an airplane on its take-off run, before becoming airborne -
- another reason why they prefer large open bodies of water.

In Bulletin No. 252 we discussed three species of diving ducks that 
commonly migrate from far north and winter along the shores of Lake 
Michigan: the American golden-eye, the white-winged scoter, and the 
noisy long-tailed old squaw which has been caught in fishermen's nets 
at amazing depths of 150 or 200 feet. The king eider and American 
eider -- sea ducks famous for their down used in the manufacture of 
sleeping bags and arctic clothing -- are less common.

The ring-necked duck, the scaup, and the lesser scaup or little bluebill, 
are diving ducks esteemed as game birds but the redhead and the 
canvasback, being essentially vegetarians, are most highly regarded by 
epicures. The redhead was once the commonest of all diving ducks but 
unfortunately, due to excessive hunting and drainage of the nesting 
areas, they and the canvasback have become scarce.

For good descriptions of all these ducks and interesting facts about 
them, we recommend the Audubon Water Bird Guide.