Winter Trend Dava = Central Flyway 
As mentioned previously, it was not possible for the Bureau of 
Sport Fisheries and Wildiite to conduct the annual survey of waterfowl 
wintering ground in Mexico curing January 1957. Isnasmich as the Fast Coast 
and central portions of Mexico usually contain from 20 to 60 percent of the 
total waterfowl recorded in the Central Flyway during the winter survey there 
is question as to whether data recorded in the Central Flyway States only are 
representative of trends in wintering population. This is particularly true 
in view of the fact that there was a recorded decrease of about 34 million 
birds in Texas between 1956 and 1957, while between 1957 and 1958 there was 
and increase of about 2 million. The species involved in the change are ones 
regularly found wintering in Mexico and circumstantial evidence points to the 
possibility that there may have been a decided shift to Mexico wintering 
areas during 1957. 
On the basis of daca collected in the United States only, ducks 
increased 96 percent as compared tc 1957, geese increased 27 percent, coot 
increased 248 percent, and waterfowl collectively increased 91 percent. On 
the same basis the species composition and percent change for individual 
species is presented in the following table. The following graph presents 
the trend in duck, goose, and coot povvlations for the period 1949 through 
1958. The data have been adjusted so that year to year comparisons are on 
the basis of comparable coverage. In making the compilation it was assumed 
that the areas covered were representative of any change which may have. 
occurred. This assumption is subject to the possible error outlined above 
particularly between 1956 and 1957 and between 1957 and 1958 
Sveeles Composition - Central Flyway - 1957 and 1958 
(Comparable Coverage) 

Percent of Birds Identified Percent 
Species 12 1958 Change 
Mallard 62.0 60.1 ~ 84.6 
Pintail 903 8.1 # 64.8 
Snow Goose 6.9 3.7 ~f lek 
Redhead Gel 567 # 78.6 
Canada Goose 305 3.0 # 6301 
Scaup 23 Tae # 545.9 
Baldpate 2.0 263 # 123.8 
Coot 1.8 305 # 274.7 
Green-winged Teal Lo} 204 # 220.9 
Merganser 103 9 # 27ol 
50 
Continued -- 
