MIGRATION ROUTES AND FLYWAY s 



51 



dining winter, and are conducive in erroneous conclusions relative to 

 abundance and to excessive slaughter. 



THE CENTRAL FLYWAY 



As previously stated, the eastern boundary of the Central flyway 

 (fig. 34) merges imperceptibly with the western boundary of the Mis- 

 sissippi flyway, but in general it is bounded in this direction by the 

 Missouri River and by the western parts of Arkansas and Missouri. The 



western boundary appears to 

 start on the north at Great 

 Salt Lake, Utah, and runs 

 southeastward across Utah 

 and western New Mexico. 



Along this flyw r ay sweep 

 flocks of ducks that in the 

 north country share a com- 

 mon breeding ground with 

 others of the same species that 

 follow in migration all the 

 other flyways. Lying across the 

 northern terminus of the 

 western boundary is the most 

 important single breeding 

 ground for waterfowl that 

 now remains in the United 

 States - - the Bear River 

 Marshes at the northern end 

 of Great Salt Lake, Utah. 

 This is still an important 

 breeding area for Pintails, 

 Redheads, Cinnamon Teal, 

 and others. A large percent- 



FIG. $4. The Central Flyicay 



age of the birds raised here 

 follow lanes of travel west- 

 ward to the Pacific flyway, but it is noteworthy that there are at least 

 three routes that leave this area in an easterly or northeasterly direction. 

 One of these, tributary to the Atlantic flyway, has already been described. 

 A second easterly route from these breeding grounds extends across 

 southern Wyoming, turns southward across the Laramie plains and 

 eastern Colorado, and by way of the Panhandle of Texas ends on the 

 Gulf coast. The third route turns southward in northwestern Colorado, 

 across the Uncompahgre Plateau, passes through the San Luis Valley, 

 and extends southward into Mexico. 



It is significant that while the Bear River Marshes are an important 

 waterfowl concentration point, where large numbers of ducks are killed 

 each season, it has furnished almost no recovery records of birds banded 

 in Canada. 



