95 
Table Il. - Aerial and Marsh - level Brood Data - Delta Marsh. 
Year Date Method Total Broods Average Brood Size 
1954 8/16 Air ! 80 = 
1954 7/26-8/11 Canoe 106 4.92 
1953 . 8/2 - Air 132 4.37 
1950 7/31 Canoe 179 5.43 
1949 7/9 , Canoe: 106 5.97 
1948 7/19 Canoe 72 6.98 
1948 -7/19 3 Air 96 - 
1947 7/25 Canoe 167 (817) 5.86 
1947 ; Wes. -- Air 196 Ze 

A comparison of 1953 and 1954 aerial data indicates that production was 
down some 39.4 percent. Comparing canoe and aerial data, production was down 
19.7 percent. That production on the Delta Marsh was down is certain. Just how 
much is uncertain. 
Summary 
Waterfowl population and production trends were studied over 44 square 
miles of prairie marsh in south-central Manitoba. 
An increased breeding population in 1954 experienced a decrease in production 
as compared with 1953. 
Phenologically the 1954 season was from ten days to two weeks later than 
1953. 
