by those that have taken the more direct route along the east coasts of 

 the bays and all then fly overland 570 miles to the estuary of the St. 

 Lawrence River. 



The Atlantic coast wintering area receives accretions of waterfowl 

 from three or four interior migration paths, one of which is of first 

 importance, as it includes great flocks of canvasbacks, redheads, 

 scaup, Canada geese, and many black ducks that winter in the 

 waters and marshes of the coastal region south of Delaware Bay. The 

 canvasbacks, redheads, and scaup coming from breeding grounds on 

 the great northern plains of central Canada follow the general 

 southeasterly trend of the Great Lakes, cross Pennsylvania over the 

 mountains, and reach the Atlantic coast in the vicinity of Delaware 

 and Chesapeake Bays. Black ducks, mallards, and blue-winged teals 

 that have gathered in southern Ontario during the fall leave these 

 feeding grounds and proceed southwest over a course that is 

 apparently headed for the Mississippi Valley. Many do continue this 

 route down the Ohio Valley, but others, upon reaching the vicinity of 

 the St. Clair Flats between Michigan and Ontario, swing abruptly to 

 the southeast and cross the mountains to reach the Atlantic coast 

 south of New Jersey. This route, with its Mississippi Valley branch, 

 has been fully documented by the recovery records of ducks banded 

 at Lake Scugog, Ontario. 



Canvasbacks migrate from the prairie pothole country of the 

 central United States and Canada to many wintering areas in the 

 United States. This duck has been the subject of a particular study 

 (Stewart, Geis, and Evans 1958), and its principle migration routes, 

 based on recovery of banded birds, are shown to follow an important 

 trunk route from the major breeding area in the prairie provinces of 

 Canada and the northern prairies of the United States southeast- 

 ward through the southern Great Lakes area to Chesapeake Bay, the 

 chief wintering area (Fig. 20). Relatively few canvasbacks proceed 

 southward along the Atlantic seaboard. A less important route 

 branches off from the main trunk in the southern Minnesota region 

 and extends south along the Mississippi Valley to points along the 

 river. Other individuals of the prairie breeding population fly 

 southward on a broad front to the gulf coast of Texas and the interior 

 of Mexico, while some proceed southwestward on a relatively broad 

 path to the northern Pacific coast. 



Mackenzie Valley-Great Lakes-Mississippi Valley 

 Route and Tributaries 



The route extending from the Mackenzie Valley past the Great 

 Lakes and down the Mississippi Valley is easily the longest of any in 

 the Western Hemisphere. Its northern terminus is on the Arctic 

 coast in the regions of Kotzebue Sound, Alaska, and the mouth of the 

 Mackenzie River, while its southern end lies in Argentina. 

 Nighthawks, barn swallows, blackpoll warblers, and individuals of 

 several other species that breed northward to the Yukon Territory 

 and Alaska must cover the larger part of the route twice each year. 



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