228 
Breeding Population Trends 
Bre ame wal Ese ak a ns oie mene 
With the spot type waterfowl breeding sampling system employed in Wisconsin, 
it is not possible to express results in ducks per square mile, as is done in the 
prime waterfowl breeding range. Rather, we gather information on the below listed 
items and on the number of flocked (believed to be non-breeding) females observed 
on the production surveys. It is felt these data combined with information on water 
conditions (i.e. floods or droughts) give us the tools to follow year to year trends 
in the Wisconsin waterfowl breeding picture. We are interested in drastic changes 
only, not minor ones. 
1951 1952 Indicate Change 
No. pairs per acre censused .078 .092 + 18 percent 
Young per breeding pair 1.55 2.74 + 77 percent 
Average brood size 6.5 6.6 + 1 percent 
Success of the Season 
Of 328 water sites covered during these surveys, 57 percent were occupied 
by some duck species or coot during the breeding ground surveys compared to 
55 percent in 1951. 
Since the late waterfowl breeding season of 1950, we have experienced two 
Spring seasons with earlier phenology. The 1951 season was about two weeks 
earlier than 1950, and 1952 was about seven days earlier than 1951. The chronology 
of the 1952 brood observations is summarized in Table II. 
In 1950 many female mallards and some female blue-winged teal were observed 
in flocks early in the season. It was assumed these birds did not breed due to the 
inclement weather, In 1951 and 1952 very few flocked females were observed in 
any species, Flocked females are tabulated in Table ITI. 
Table IV shows that 520 pairs of breeding ducks produced 216 broods. 
Complete counts on 171 broods gave an average of 6.6 young per brood. 
Table I shows that of 328 water sites censused three times during these surveys, 
87 percent showed no change or more water during the production surveys (second 
and third coverage) as compared with the first coverage. 
