Winter Trend Data - Mississippi Flyway 
_ In the, MISSISSIPPI FLYWAY ee the past several years there is 
little question but that changing: conditions at the time of the annual winter survey 
have affected the population trend data. When the lower Mississippi Valley is 
dry the birds. tend to concentrate on rivers and reservoirs, where they are 
easily seen. When the river bottoms flood, as they usually do some time during 
late fall or early winter, ducks,-particularly mallards, are attracted into the 
bottoms to feed. Suitable techniques-for censusing the birds when they are in 
the bottoms have not been developed. In 1951, the bottoms were flooded but 
frozen during the survey period, a condition which forced the birds into the 
open where they could be counted. In 1952, the bottoms were flooded, and it is 
probable that the decrease in mallards observed that year resulted from not 
being able to find the birds, and not that a decrease in population occurred. 
In 1953, 1954, 1955 and again in 1956 a drought condition existed.and the 
bottoms were not flooded at the time of the survey. Asa result the birds were 
in the open and could be counted. It is probable that the winter survey data 
have been roughly comparable.for the past three years. 
It is of interest to note that in spite of the cold fall and early winter 
that more mallards wintered north of the Ohio River than south of it in the 
Mississippi Piywey: 
Percent Change in Mississippi Flyway (Continental) Population Index Figures 
for Ducks, Geese, Swan and Coot from January 1955 to January 1956. 
Area . Ducks Geese Coot... Total 
Ontario - 8 +67 - fo - 7 
Mississippi Flyway 
States 440 +13 +8 +36 
Total Le +40 -+13 . + 8 +36 
