
Winter Trend Data - Central Flyway 
As mentioned previously, it was not possible for the Bureau 
of Sport Fisheries and Wildlife to conduct the annual survey of water- 
fowl wintering areas in Mexico during January 1957. Inasmuch as 
the east coast and central portions of Mexico usually contain from 
about 20 to 60 percent of the total waterfowl recorded during the 
winter survey in the Central Flyway, there is question as to whether 
the 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 the wintering population recorded in Texas decreased 
nearly 3, 700,000 birds as compared to 1956, apparently due to the 
prolonged drought in the State, and the species involved in the decrease 
are regularly found wintering in Mexico in large numbers. 
On the basis of data taken in the Central Flyway States alone, 
ducks decreased 45 percent, geese decreased 36 percent, coot de- 
creased 50 percent, and waterfowl collectively decreased 44 percent. 
On the same basis, the percent change by individual species was as 
follows: | 
Species Composition - Central Flyway States -- 1956 and 1957 
(Comparable Coverage) 
Percent of Birds Identified Percent 

Species 1956 1957 Change 
Mallard 31..0 63.6 + 14.9 
Pintail 27.9 7.5 - 85.0 
Redhead 16.8 6.2 - 79.4 
Snow Goose 6..8 7.0 - 42.3 
Scaup 5.6 2.4 - 76.3 
Baldpate 3.7 2.0 - 69.4 
Canada Goose 2.7 3.5 - 26.6 
Coot 250 1.8 ~ 50.1 
Merganser on 1.4 + 12.9 
Green-winged Teal .7 1.4 + 20.9 
Continued -- 
42 
