
240 
Wood Duck Brood Production 
The preliminary brood survey conducted between May 3 and 16 on three 
transects totaling 47 river miles, (Figure 1) indicated that the adult male wood 
duck population was about eight percent below, and the adult female population 
about 34 percent below the 1952-53 averages for the same transect. 
The 143 river miles in the nine transects floated this year during brood- 
ing were the same as those covered in 1954. An all-time low of 56 broods of 
wood ducks was observed, for an average of 39.2 broods per 100 miles of transect. 
The average is 37 percent below the figure for 1954, and about 40 percent below 
the previous three year average. 
Whole counts were obtained on 32 wood duck broods. The average young 
at the time of observation was 8,6, and numbers ranged from 2 to 14. This 
average brood size and the 39,2 broods per 100 miles, gives 337 young per 100 
miles (Figure 2). Compared with the previous four years, the brood size in 1955 
was 0.8 bird above the average. 
Since onlytwo broods of wood ducks were observed during the preliminary 
survey, from the distribution of age classes given in Table [, and from information 
gained through follow-up floats on three transects, it is concluded that the regular 
nine transects were inventoried during the period when a maximum number of 
broods could be observed. 
Standard wooden type wood duck nesting boxes on the Willow Slough State 
Game Preserve were inspected this year on July 7 and 8. Two of the 67 boxes 
were determined to be unsuitable for nesting. Five of the 65 serviceable boxes 
held evidence of successful clutches, compared with 6o0f 65 in 1954. All five 
successful boxes this year were located over open water. 
On August 15, 14 metal Predator proof" nesting boxes were inspected. 
These boxes were erected along the Big Blue River in Shelby and Hancock : 
Counties on March @, 1955. There was no evidence of wood duck nesting. 
An additional 10 metal type boxes, erected at Jasper-Pulaski State 
Game Preserve on February 19, 1955, were inspected on August 26. Two of these 
nesting boxes held evidence of successful wood duck clutches. 
Summary 
Water levels during the brooding period were determined to be good, 
and considerably improved over conditions one year ago. 
The preliminary river transect survey indicated the numbers of both 
adult male and adult female wood ducks had declined, eight percent and 34 percent 
respectively, compared to the average of comparable data for the years 1952-53. 
