35 
The increase may be attributed to the blanket of stubble and swath that 
presented itself to the birds upon their return -- much of it soaked by newly 
flooded areas. To some species it represented abundant food; to others it also 
meant prime nesting cover. 
Success of the Season 
A summary of the brood survey by strata is to be found in Table IT; 
species composition is presented in Table III. Chart 2 presents the comparison 
of significant data with 1951 and 1949, 
Progress 
The advanced state of the first nesting attempt was indicated when at the 
very start of the May inventory, post nesting flocks of 10 to 15 drakes (mallards 
and pintails) were noted. On some transects in the southwest over 90 percent of 
the pintails seen were drakes. Later nesting in the central and northern areas 
lowered the over-all drake figure to 57.6 percent. 
Density 
The aerial data indicate that Saskatchewan's doubled breeding population 
produced more than three times the number of broods recorded in 1951.. 
1952 - 4.37 broods per square mile 
1951 - 1.34 broods per square mile 
The success of this year's effort is also emphasized by the ratio of July 
broods to May pairs: 
1952 - 1 brood: 4.4 pairs 
1951 - 1 brood: 7.0 pairs 
Distribution 
Furthermore, there is a better distribution of broods throughout the 
surveyed area as determined by the number of 10-minute transect intervals in 
which broods were recorded: 
1952 - 82 percent of 363 intervals were occupied 
1951 - 70 percent of 253 intervals were occupied 
Brood Size and Mortality 
Class I Class II Class III Average Total Broods 
1952" 
(Air) 7.3 [pee al 7.1 Tos 1 757 
1951 
(Ground) 6.8 6.2 6.5 6.6 1,037 
This year's large brood size probably reflects the success of first attempts, 
particularly of mallards and pintails, since first clutches usually are larger than 
those of re-nesters. This, in turn, may suggest unusually light predation in the 
western prasslands. With near-drought conditions prevailing for the few years 
previous to 1951, and with a greatly increased water and waterfowl supply this 
