THE WATERFOWL FLYWAYS OF NORTH AMERICA 



11 



were groups of birds indigenous to the Mississippi flyway, forcibly 

 removed, and liberated in the Atlantic and the Pacific flyways where 

 others of their own kind were relatively common, but which refused 

 to follow these flyways, as indicated by the fact that a succeeding 

 season finds them back in their original winter quarters. 



Surely, no further proof is necessary to show that the waterfowl 

 conditions in any one limited area cannot be applied as a criterion to 

 the entire continent. Such being the case, it becomes of more than 

 passing interest to examine the data collected by the Biological Sur- 

 vey from all sources during the spring and summer of 1934, and 

 apply these data to the various flyways on which they were obtained. 

 In table 1 the comparison is with the same season in 1933. Since 

 that season was generally admitted to be far below normal, the re- 

 ports of " no change '•' might, with justification, be added to the 

 heading " decrease." 



Table 1. 



-Status of game icaterfowl in the four major flyways in 1934, compared 

 with 1933 





Flyway 



Observers reporting— 





Increase 



No change 



Decrease 





86 

 74 

 43 

 41 



117 

 123 



88 

 65 



120 





114 





171 





122 







The figures indicate that the birds of the Atlantic and Mississippi 

 flyways were relatively more abundant in the 2 years than were those 

 of the Central and Pacific flyways. The reason is not difficult to find. 

 On the Atlantic coast the black duck and the Canada goose have held 

 their own fairly well, chiefly because little if any of their breeding 

 grounds have been adversely affected by agriculture, drainage, 

 drought, or other factors x ; while the principal game ducks of the 

 Mississippi flyway are the mallard and the pintail, both of which 

 have extensive breeding ranges, large parts of which are north of the 

 affected regions. Moreover, in both the Atlantic and the Mississippi 

 flyways the shotgun has been almost the only destructive factor on 

 the migration routes and in the winter quarters. Though drainage 

 has been a disturbing factor on these two flyways, there has not been 

 the devastation due to disease, drought, and drainage that has con- 

 tributed to decimate the flocks of the Central and the Pacific flyways. 



SUMMARY AND CONCLUSIONS 



Four definitely recognizable flyways are followed by waterfowl 

 on their spring and fall migrations in the United States. Covering 

 practically the whole country and extending northward into Canada 

 and southward into Mexico, these flyways are readily definable by 



1 Many reports on the black duck were received while this circular was in process of 

 publication, showing that this species also suffered a serious reduction in number during 

 the year, due in part to the severity of the winter of 1933-34 on the Atlantic coast. 

 According to well-qualified observers, the fall flight of 1934 was not more than 25 per- 

 cent as great as that of 1933. 



