58 
Table IX - Pair-Brood Data - Redvers Study Area (5 Square Miles) 
Breeding Pair Census Percent Percent Production 
Species May 10. July 25 Breeding Species Brood Species Percent _ 
Pairs Pairs Population Comp. Production Comp. of Pairs 
Mallard 265 1 264 45.0 122 49.0 46.2 
B-w. teal 142 8 134 22.8 62 24.9 46.3 
Pintail 64 - 64 10.9 19 7.6 29.7 
Baldpate 32.—« 2 30 5.1 12 4.8 40.0 
G-w. teal 32 2 30 5.1 14 5.6 46.7 
Canvasback 23 - 23 3.9 9 3.6 39.1 
Lesser scaup 15 - 15 Z2.5 2 0.8 13.3 
Shoveler 12 - 12 2.0 6 z2.4 50.0 
Gadwall | 7 - 7 1.2 2 0.8 28.6 
Ringneck 4 - 4 0.7 1 0.4. 25.0 
Redhead 4 - 4 0.7 - - 0.0 
Ruddy 1 1 0 .0 - - - 

Total 601 14 587 249 42.4 
These brood data are not complete due to the fact that a few incubating hens 
remained on nests and of course could not be censused. 
Due to the very few adult ducks seen during the final census, plus the fact 
that no nests were found by the dog indicates that the number of remaining hens 
on nests was very small so that the final success figure would certainly not be 
over 50 percent. There is a good possibility that breeding success for the scaup, 
gadwall and ringneck was higher than indicated due to their late nesting habits. 
Taking into consideration both nesting and pair-brood success, a figure of 
45 percent should be a conservative estimate of production. Applying this figure: 
to the 600 pairs present in May we get a production of 270 broods with an average 
Class III brood size of 6.25 for a total of 1,688 ducklings. These 1,688 juveniles 
added to the original 1, 200 adults, represents an increase of from 1, 200 to 2, 888 
ducks which is 2.4 times the original population or an increase of 140 percent. 
This increase indicates a very satisfactory breeding season. 
Table X - Brood Averages - Age Classes 
No. of 
Species Class 0* Class I ‘Class II Class III All Broods 
Mallard 6.96 6.16 6.57 6.13 6.42 393 
B-w. teal 8.87 7.97 7.34 7.25 7.94 220 
Pintail 6.40 5.25 6.50 5.00 5.62 40 
Baldpate 8.40 7.13 7.83 7.00 7.81 «43 
Canvasback 7.25 6.25 6.09 5.64 6.28 53 

* Class 0 is made up of broods one week or less in age. 
The above brood averages were compiled from data collected either on the 
study area or in the general area surrounding it. No comparable data for 1951 
are available but data from the Dakotas for the mallard showed a Class III average 
of from 6.25 to 7.00 for the 1949-51 period and 7.25 to 7.74 for Class [II blue-wings. 
