83 
Table III. - Broods on 120 Study Potholes 
July 8-23 - 1952 July 5-23 1953 
Broods Species Comp. Broods Species Comp. 
Species Percent Percent 
Mallard 35 340 43 46 
Gadwall 1 1 0 - 
Baldpate 4 4 4 4 
Pintail 10 10 7 8 
Green-winged teal 7 7 2 2 
Blue-winged teal 16 15 10 11 
Shoveler 4 4 5 5 
Redhead 3 3 7 8 
Canvasback 7 7 11 12 
Lesser scaup 5 5 2 2 
Ruddy duck 6 6 0 - 
Others 6 6 2 2 
SS Ee LS a yar Ses 
Total 104 93 
Age Class No. Broods Percent No. Broods Percent 
I 32 36 39 60 
Il 14 16 12 19 
III 44 49 14 22 
90 (+14 unaged) 65 (+28 unaged) 
Trend - 11 percent 

Nests 

Nesting studies again showed that over-water nesting species have higher nest 
success than land nesters, and the importance of re-nesting to most dabbling ducks 
is emphasized (see Table IV). Mallard nest histories showed that nests active during 
the period of sub-freezing temperatures and snow, May 11-16, were as successful as 
nests started after May 16. A disproportionate number of mallard nests in the egg- 
laying stage at the time of heavy rains, May 24 = June 3, were unsuccessful, 
Table IV. - Average Brood Sizes by Age Classes, 1949-1953 - Newdale-Erickson 
District, Manitoba 

vclass I Vlass II Class III 
Year Av. Size No. Broods Av. Size No. Broods Av. Size No. Broods 
1949 7.0 329 7.0 138 6.5 130 
1950 6.5 173 5.8 71 6.3 86 
1951 6.8 302 6.5 128 7.1 99 
1952 7.2 166 6.4 66 7.3 67 
1953 6.6 261 Bis 122 6.6 44 
{Pr dP ec eee Ee 
