
253 
Brood Surveys 
Following the boat surveys to determine potential breeding populations, 
brood censuses were made on the same sample check areas to determine nesting 
success. Information obtained from these brood censuses can be used only as an 
indéx of production, since many broods are unobserved in the dense cover typical 
of our marshes, 
Comparing these brood census figures with those obtained in previous years, 
poor production is indicated. The number of broods observed per lineal mile of 
census line was 50 percent lower than last year, and below the previous five-year 
average. The average size of the broods, however, was the highest in five years 
of records. Comparisons are shown below. 
Hens and Bachelor Average Size 
Broods Per Young Per Ducks Per of Broods 
Year Lineal Mile Lineal Mile Lineal Mile Observed 
1949 47 2.75 6.50 6,00 
1950 . 34 2.32 5.50 5.87 
1951 635 2.20 3.31 5.76 
1952 .70 3.92 3.21 4.60 
1953 51 3.63 4.32 6.10 
1954 .20 1,45 4.60 6.24 
In another survey a portion of the southern farm land was censused fram 
the air to further test the practicability of aerial observations for counting broods in 
the least wooded portions of the State. This pilot study was started in 1952, and 
comparative data are available. A continuous census route was flown which included 
parts of the transects previously flown for breeding pair counts. This brood census 
route is shown on Figure 1. The sample area includes 272 lineal miles of census 
line one-quarter mile in width, or 68 square miles. It has been flown for the past 
three years. The results follow: 
1952 1953 1954 
Bachelor birds 12 7 16 
Adult female and young 5+35 11+78 5+22 
Total birds 52 96 31 
Young per brood 7 Tal 4.4 
Broods per square mile 073 162 . 044 
Hens and young per square mile . 588 1, 308 399 
Young per square mile 514 1.147 323 
Bachelor ducks per square mile .176 . 103 2.35 
Insufficient numbers of birds were observed on these aerial broods 
surveys to provide statistically significant figures. 
