MIGRATION ROUTES AND FLYWAYS 49 



cept the Ring-necked Duck, breed in the eastern part of the continent, 

 so practically every Canvas-back, Redhead, and Greater and Lesser 

 Scaup 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 re- 

 gion of western New York, and occasionally these birds are noted in New 

 England waters, but the main body reaches the coast south of New Jer- 

 sey. With them are some Pintails, Gadwalls, Teals, and other shoal- 

 water species that also have bred in the interior. 



A most interesting tributary of this northwestern route has its start- 

 ing 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 Dako- 

 tas, 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, which in winter is sometimes 

 present in large rafts in waters adjacent to Long Island, and the Scoters 

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



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, Missouri, and, striking across the moun- 

 tains, reaches the coast of South Carolina. This route is followed by 

 Blue-winged Teals, and probably by some Gadwalls, Shovellers, and pos- 

 sibly by some Ringnecks. The last-named species, however, is chiefly a 

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

 ern Georgia and northern Florida, it is significant that of several hundred 

 banded in Georgia, not one has been recovered from a point on the At- 

 lantic coast, their route of migration being through the Mississippi 

 Valley. 



It will thus be seen that the Atlantic flyway is a complicated system 

 of migration routes. 



THE MISSISSIPPI FLYWAY 



In some respects the Mississippi flyway (fig. 33) is relatively simple, 

 although it has at least one complicating feature. Its eastern boundary 

 runs through southern Ontario to western Lake Erie, thence across Ohio 

 and Indiana to the Mississippi Valley, where it closely follows the river 

 to its mouth. This line is clearly defined. The western boundary, how- 

 ever, does not permit such precise definition, for the reason that in 



