CHAPTER © Vi. 
WARM-WEATHER DIVERS. 
GeENus Aythya—SupceENus Fuligula. 
Aythya marila—B.LuvuEBILL, BLACKHEAD, RaFr OR 
PrLoarine Duck,.)Scaup Duck:— Habitat. — North 
America, from ocean to ocean; north through British 
America; south to West India Islands and Central 
America. The principal flights through the interior 
are up the Mississippi, Missouri, (Canadian and Ohio 
rivers, branching from the former over the Fox Lake 
region and northern lakes of Illinois northward. 
The first issue stays but a short time, soon passing 
northward as fast as the ice disappears, for they rarely 
leave the frost line until the ice has departed, working 
up in the interior, through the lakes and overflowed 
bottoms below St. Louis, following behind the ring- 
bills. Some years they arrive in great numbers, while 
at other seasons they are very few. They prefer still 
to running water; naturally, large ponds and lakes, 
bayous, bays and inlets are their favorite resorts. They 
do not mix much with either Affinis or Collaris, pre- 
ferring their own species. Many birds are killed 
whose measurements are below their standard, but not 
reaching the small size of Affinis; whether they inter- 
breed in their northern homes remains a question, for 
both Marila and Affinis use the same northern nesting 
grounds. The second issue arrives a few days after 
the main body of the first has departed, and stays a 
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