
This data indicates poorer success in 1950 if the dates are phenologically 
the same. However, neither brood count was taken during the peak of the hatch. 
There are unquestionably too few data (especially brood data) included in the above 
table and formulae to make the indices absolutely accurate, However, brood 
transects are now set up in North and South Dakota which should give adequate data 
in the future, 
The second method of measuring brood survival is one which compares the 
success of one species with another by comparing species composition. Table 6 
illustrates this method. 
Table 6. -- Species Percentage Composition - Breeding Pairs vs Broods 
South Dakota North Dakota 
Transects C, D, E, & K Transects 1, 4, 6, 8, & 12 
: Breedin Total No. reedin Total No. 
PEC CIES Pairs . eos of ries . Broods of 
Ducklings Ducklings 
Percent Percent Percent Percent Percent Percent 
B-w. teal 41.8 55.1 59.4 30,4 46.4 49.6 
Pintail 12.9 13.7 9.6 27.8 13.0 9.7 
Mallard — 15.8 10.0 9.3 14.0 10,4 9.0. 
Gadwall 12.7 8.3 9.8 7.1 10.4 12.0 
Shoveler 6.2 2.9 3.2 8.7 7.0 7.4 
Redhead 4,0 4.0. 3.4 3.3 1.8 1.9 
Ruddy duck 2.4 2.9 3.3 3.7 3.4 2.6 
Baldpate 1,3 1.1 0.9 2.1 2.2 2.2 
Canvasback L.2 0.6 0.2 2.0 2.4 1.8 
Lesser scaup 1,0 1.4 0.9 0.7 3,0 3.8 

The data in Table 6 merely indicate the comparative breeding success 
between species. They show, for example, that in South Dakota the blue-winged teal 
and ruddy duck were the only two species which increased in comparative abundance 
between the nesting and brooding season. Considering the number of broods produced, 
the pintail and redhead were also quite successful. This compares favorably with 
brood success as indicated in Table 5. 
In North Dakota, according to Table 6, the blue-winged teal and gadwall 
were the most successful breeders. The method used in Table 6 to determine 
production is only relative and there is some chance for error. Pintail production 
is probably a bit better than indicated. Early hatched broods are kept in heavy cover 
in temporarily flooded meadows and so may be not all recorded. Later on, these 
areas dry up and force most ducklings to more open areas where observation is 
possible. By this time, however, some pintail broods can fly and are missed 
entirely. 
Brood Averages 
Over 2,000 broods were recorded in the Dakotas of which l, 936 were 
considered to be complete broods and were accurately counted. Brood counts were 
made on and off of Transects from June 18 to August 29 in 1950. 
