TABLE C-4,--Trend in waterfowl numbers, Pacific Flyway extended, 
winter survey, 1949-63 
[In thousands | 
emus tC ee 17 

see eee ee 
i 
Note.--Coverage during the period was not comparable and the data were ad- 
justed, using 1959 and 1955 as base years. It was assumed that areas where 
comparable surveys were conducted provided an accurate measure of the per- 
centage change between 2 consecutive years. On this basis, population esti- 
mates were calculated backward and forward from the base years. The 1962 
figures are based upon only observed birds and are not adjusted. 
1 Index arbitrarily reduced from 1,797,000 to 1 million geese. During 
January 1951, more geese were estimated to be in Merced County, California, 
than were in the entire flyway either the previous or the following year. 
It seems certain that the estimate was in error. If the geese recorded in 
Merced County are deleted from the totals for 1950, 1951, and 1952, and a 
revised estimate is calculated based on change observed in the remaining 
areas, the index for 1951 is about 1 million birds. 
2 No surveys were conducted in Mexico in 1957. The data indicate that it 
is unlikely that surveys in the United States, Canada, and Alaska accurately 
revealed the trend in wintering populations of ducks that year. 
82 
