4 CIRCULAR 3 4 2, U. S. DEPARTMENT OF AGRICULTURE 



the general course taken by the diving ducks and others that come 

 from the great interior breeding grounds. No diving ducks breed 

 in the eastern part of the continent, so practically every canvasback 

 (Nyroca valisineria) , redhead (N. americana) , and scaup (N. marila 

 and N. afpnis) that is seen in winter in Chesapeake Bay, Back Bay, 

 and other middle-Atlantic coastal waters, has pursued this route. 

 Some moderate-sized flocks do travel eastward along Lake Erie to 

 the Finger Lakes region of western New York, and occasionally 

 these birds are noted in New England waters, but the main body 

 reaches the coast south of New Jersey. 'With them are some pin- 

 tails (Dafila acuta tzitzihoa), gadwalls (C haulelasmus streperus) , 

 teals (Nettion and Querquedula) , and other shoal-water species that 

 also have bred in the interior. 



A most interesting tributary of this northwestern route has its 

 starting point in the Bear River Marshes of Great Salt Lake, Utah, 

 and is apparently used exclusively by redheads. As conclusively 

 shown by banding records, many redheads banded as ducklings in 

 these marshes start their fall journey by first flying north across 

 southeastern Idaho and northwestern Wyoming, turn eastward across 

 Montana, the Dakotas, Minnesota, Wisconsin, and Michigan, and, 

 joining others of their species en route out of the Prairie Provinces 

 of Canada, continue to the Finger Lakes region of western New 

 York, or to the coasts of Maryland and Virginia. This is probably 

 one of the most remarkable migration routes of all North American 

 waterfowl, and it is interesting to observe that in crossing from west 

 to east through the Dakotas, Minnesota, and Wisconsin, many of 

 these birds are actually flying at right angles to others of their own 

 kind that are following routes from the north to the Mississippi or 

 the Central flyways. 



The greater scaup, or big bluebill (Nyroca marila), which in winter 

 is sometimes present in large rafts in waters adjacent to Long 

 Island, and the scoters, or "sea coots" (Melanitta and Oidemia) of 

 the New England coast, also come chiefly from interior points. 

 Their routes across Canadian territory, however, are not yet well 

 understood, although, as stated by Cooke, in the case of the white- 

 winged scoter (M. deglandi) it appears that the birds leave their 

 summer home west of Hudson Bay and travel nearly due east to 

 coastal Labrador. Thence, traveling across the Gulf of St. Lawrence 

 and along the coast, they reach their winter home, which extends 

 from northeastern Maine to Chesapeake Bay. 



Another tributary route to the Atlantic flyway is really a branch 

 from the Mississippi flyway that apparently leaves the parent stream 

 in the general vicinity of St. Louis, Mo., and, striking across the 

 mountains, reaches the coast of South Carolina. This route is fol- 

 lowed by blue- winged teals (Querquedula discors), and probably 

 by some gadwalls, shovelers (Spatula, clypeata), and possibly by 

 some ringnecks (Nyroca collaris). The last-named species, however, 

 is a Mississippi-flyway bird and, while in winter it is often plentiful 

 in southern Georgia and northern Florida, it is significant that of 

 several hundred banded in Georgia, not one has been recovered from 

 a point on the Atlantic coast, their route of migration being through 

 the Mississippi Valley. 



