50 BIRDS OF SOUTH DAKOTA 
Mergansers; Anatine, River Ducks; Fuliguline, Sea Ducks; 
Anserine, Geese; and Cygninz, Swans. 
SUBFAMILY MERGINA.. MERGANSERS 
The Mergansers are represented in North America by 
three species, all of which have been taken in South Dakota. 
Since the hind toe is webbed, they are classed by some authors 
as Sea Ducks. They are very appropriately called Fish Ducks, 
as they have narrow, round biils with saw-like teeth, showing 
that their habits of feeding are different from those of the true 
Ducks. The Mergansers are seldom used for food in our State; 
since they feed almost exclusively on fish and frogs their flesh 
has a “fishy flavor.” In migration they are among the last of » 
this family of birds to go south, and are never seen in large 
flocks like true Ducks. 
129. MeErGANSER (Mergus americanus.) 
“Fish Duck,” “Sheldrake.” 
These are about the size of Mallards. The male has a very 
dark blue head, white breast and belly, white and black wings, 
and gray back. The female, entirely different from the male in 
plumage, has white chin, reddish brown on crown and crest, 
white under parts, and gray back. 
While a few pairs may occasionally nest in South Dakota, 
their nesting locality is much farther north. A few are shot each 
year in migration by hunters. 
130. ReEp-BREASTED MERGANSER (Mergus Serrator.) 
Smaller than the American Merganser. The dark green 
head of the male has feathers longer than the head of the Ameri- 
can. Breast brown with black spots; under parts light; wings 
whitish; back black. The female has crown ashy brown; back 
gray; and the end of wing feathers white. Migratory only, as 
their nesting grounds are well towards the Arctic Circle. 
131. Hoopep MeErcanser (Lophodytes cucullatus.) 
This is the smallest of the Merganser family. The male 
has a large black and white hood, black neck, white under parts, 
and black back. The female is similar but with brownish head 
and gray neck. These birds summer occasionally in South Da- 
