
239 
Results of Breeding Ground and Production Surveys 
For the first time since 1951 the percent of censused water sites which 
were occupied by ducks during the breeding pair survey decreased. From 1951 
through 1954 the percentage occupied steadily increased from 55 to 64 percent. In 
1955, 55 percent of the water areas censused were occupied. The number of breed- 
ing pairs of ducks observed per acre this year was below the 1954 figure but above 
the average for the previous four years. 
Of the flocked birds observed this year, the percent of female ducks in 
the flocks was the second lowest since 1951. Apparently early favorable weather 
conditions resulted in more females bringing off broods from first nesting attempts 
and gave renesting ducks ample time to start new nests. As a consequence, fewer 
females were forced to abandon first nesting or renesting attempts. 
Complete counts on 107 broods gave an average of 7.4 ducklings per 
brood, the highest average brood size on record for Wisconsin. An estimated total 
of 495 pairs of breeding ducks produced 126 broods. Therefore, 495 pairs of ducks 
produced an estimated total of 932 ducklings, Indicated known duck production in 
Wisconsin during 1955 was 1.88 young per adult breeding pair. 
Data on the average brood size of each species are summarized in 
Table IV. The majority of the broods were observed between June 21 and June 30, 
with slightly less than half falling in the Class II age category (Table V). 
In addition to the regularly scheduled breeding and production surveys 
which were reported to the Fish and Wildlife Service by July 25, the Service 
requested that brood surveys be continued in August to determine how much of the 
annual production occurs after the deadline for the regular July report. To continue 
the production surveys beyond their present scope in Wisconsin is not practical 
when considering the number of broods observed and cost involved. However, 
through the courtesy of Refuge Manager Lloyd Gunther and the field work of Ronald 
Labisky, student assistant at the Horicon Marsh National Wildlife Refuge, some 
data are available on the production occurring after the July deadline on the best 
waterfowl producing area of the State. Table VI presents the Class Ia waterfowl 
broods observed during the 1954 and 1955 seasons. The indications are that about 
one-third of the waterfowl production can occur after the deadline date for the 
annual report. The actual percentoccurring after the due date depends upon the 
phenology of the nesting season. In 1954 the season was near normal; in 1955 the 
nesting season was seven to 10 days early, The deadline date of July 25 for the 
production survey report is adequate to cover a normal or an early nesting season, 
but is not adequate to cover a late nesting season. However, during the past nine 
years only 1950 can be considered very late. It is concluded that the July 25 dead- 
line for the brood survey is satisfactory for Wisconsin. 
Broods of Canada geese raised by free-flying parents were received 
from six counties in Wisconsin. Areas on which goslings were produced in previous 
-years and where young were present this year included the Suamico Game Sanctuary 
and the Bay Beach Wildlife Refuge (both in Brown County), the Horicon Marsh 
