150 
Figure 1 and the data for each county and the total sample appear in Table 1. The 
density of ducks on ground transects is expressed as "total pairs" and "total ducks'' 
per square mile. The former represents pairs actually observed as such plus the 
pairs indicated to be present by the presence of lone drakes, Total ducks refers to 
all of the ducks actually seen on the transects with no correction for females on the 
nest, and included unpaired as well as paired birds. 
The 22 ground transects which were run in 1949 and 1950 covered 309.1 
square miles, The number of total pairs and total ducks observed on these transects 
were 5,585 and 9,574 respectively, indicating an average density of 18.0 total pairs 
and 31.0 total ducks per square mile. This is a 29 percent increase over the 1949 
density of 14.0 total pairs per square mile and a 22 percent increase above the 1949 
density of 25.4 total ducks per square mile. Two thousand, seven hundred and seventy- 
three coots were recorded, which indicates an average density of 9.0 coots per square 
mile. This is double the 1949 level of 4.5 coots per square mile. 
Trends in Species Composition 
Trends in the species composition of the breeding ducks were calculated from 
the ground transects which were run in both 1949 and 1950. The percent composition 
was calculated from the number of tetal pairs which were observed on this sample. A 
comparison of the species composition in 1949 and 1950 is made in Table 2. Three 
changes are evident: The blue-winged teal decreased 2 percent and the pintail and 
ruddy both increased 1 percent in respect to their percent composition of the total 
population. 
Table 2. -- Trends in the Species Composition of the Breeding Population 

Number of Percent Percent 
Species Total Pairs Composition Change 
1949 1950 1949 1950 
Blue-winged teal 2,227 z2,413 45 43 -2 
Pintail 829 1,084 18 19 - fl 
Mallard . 853 975 17 17 0 
Shoveler 426 513 9 9 0 
Gadwall 260 261 5 5 0 
Redhead 161 151 3 3 0 
Ruddy 53 84 1 2 ~l 
Scaup 64 36 1 1 - 0 
Baldpate 36 45 l 1 0 
Canvasback 13 19 -1 -1 0 
Totals 4,922 5, 586 
Brood 'Census" 
The data relating the number of broods seen during the brood "census" to the 
number of pairs of ducks and the square miles covered appear in Table 3. To compare 
the number of broods to the number of pairs, the number of pairs was taken from the 
portions of the spring ground transects which were covered during the brood census. 
In relating numbers of broods to square miles covered, the same transect width (1/4 
mile) was assumed as was used in the spring ground transect survey. It should be 
remembered that these values are nothing more than indices and are of little value 
until next year's data can be compared with them. 
