256 
WATERFOWL BREEDING GROUND SURVEY IN INDIANA 
James D. McCall 
Introduction 

A waterfowl breeding ground survey was conducted again this year by the 
Indiana Department of Conservation, through its Pittman-Robertson Wildlife 
Research Project, Thirteen study areas and eight river transects were re-studied 
to obtain trends on both breeding populations and brood production. In addition a 
few exploratory surveys were conducted. 
The census techniques were essentially the same as those described in the 
1951 report. 
Weather and Water Conditions 
State -wide temperature and precipitation were normal during April and May. 
June averaged 5 F., and 0.88 inches above normal. Weather conditions, migration, 
and nesting were about two weeks earlier than last year. 
The water level in potholes was maintained at normal to above normal through 
mid-July. By mid-August many of the shallow potholes had gone dry. Losses from 
fluctuating water levels were not observed and were believed to be small, if any. 
In general, conditions have been favorable for waterfowl breeding in Indiana this 
year. 
Breeding Population Trends. 
It has become increasingly apparent that it is impossible to make a pre-brood 
census without encountering many migrant birds involving several species that do 
not normally nest in Indiana. It is also apparent that the 3 species most frequently 
observed nesting within the State have definite habitat preferences. 
Under our present census methods, 95 percent of the wood duck broods 
observed are produced on rivers, while mallards and blue-winged teal show an 
equally high preference to potholes for rearing young. Itis, therefore, bélieved 
that the breeding population should be considered only in the habitat characterized 
by species utilization. 
The calculated breeding pairs, according to habitat, indicate an increase in 
wood ducks and mallards, while blue-winged teal show a decrease (see Table I). 
Within the past three years, broods have been recorded for the following 
species: wood duck, mallard, blue-winged teal, black duck, hooded merganser, | 
lesser scaup, Canada goose, coot, and Florida gallinule. Coverage has been 
insufficient to present trend information on the latter six species, but it is believed 
that their production in this State has little affect on the flyway population. 
The breeding population trend studies cover the period from April 22 to 
May 24, 1952. 
