218 
WATERFOWL BREEDING GROUND SURVEY IN INDIANA, 1953 
James D. McCall 
This is the 5th consecutive year that Indiana has cooperated with the U. S. Fish 
and Wildlife Service in conducting a waterfowl breeding ground survey. 
The State has been arbitrarily divided into 3 zones -- southern, central and 
northern, and river transects were studied in each zone (Map 1). A light weight boat 
and a5 h.p. outboard motor were used again this year for floating the rivers. 
A number of potholes were studied again this year for trend data on both 
breeding populations and brood production. These areas are located in northern 
Indiana and were censused by a 2-man crew wading and beating out possible hiding 
cover. 
Several potholes have been studied this year for the first time and do not yield 
comparative information. Therefore, only the comparable data for the river transects 
and study areas are included in this report. In addition, a limited amount of aerial 
brood censusing was conducted in LaGrange and Steuben Counties. Useful data 
gathered during this flight will be treated separately in the text. 
The study leader was assisted on the river floats by Conservation Officers and 
Pittman-Robertson personnel, 
Weather and Water Conditions 
February was unusually mild and dry, and although a variety of weather was 
experienced during March, it was predominately warm and slightly above normal in 
precipitation. April averaged cold, windy, and below normal in precipitation. Weather 
data for periods later than April are not as yet available, but conditions have been and 
are dry. Approximately 50 percent of the 14 pothole study areas were dry by the end 
of May. The aerial survey on June 30 surveying 56 square miles in Noble, LaGrange, 
and Steuben Counties revealed that of the 162 potholes which normally should hold water 
through June - 112 or 69 percent were dry. 
Breeding Population Trends 
Censusing of breeding pairs was conducted between April 20 and May 30, 1953. - 
Seven river transects, involving 105 miles, indicated a 2 percent increase in the wood 
duck. Fifteen pothole study areas in 11 northern Indiana counties were comparable 
with 1952, and showed a 73 percent decrease in the mallard and 22 percent increase 
in the blue-winged teal. 
The mallard is the only one of the 3 species that correlates with the 1953 brood 
survey. It should be remembered that the small sample represented by the mallard 
and blue-winged teal breeding ranges tends to magnify the percentage change from 
year to year. ; 
The blue-winged teal migration was late this year, but it was impossible to tell 
to what degree this late migration affected the validity of the breeding populations 
survey until the brood census was completed. This explains one of the reasons why 
we are inclined to rely almost entirely upon the results of the brood survey. 
