MISSISSIPPI FLYWAY 
INDIANA 
Breeding Population Indices 
The reproductive success of the wood duck has recelved primary con- 
sideration, and has been investigated by systematic coverage on nine stream 
sections totaling 143 miles. ‘The stream sections and methods have been w- 
changed since 1952, and essentially unchanged since 1950. 
Three stream sections totaling 47 miles have been covered between 
April 24 and May 9 in 1952, 1953, 1955, 1956, 1957, and 1958. Eighty-four 
males and 37 female wood ducks were observed this year. Observed males were 
87 percent above the figure for 1957, and 47 percent above the previous five- 
year average. Observed females were 118 percent above those of 1957, and 
58 percent above the previous five-year average. No wood duck broods were 
observed on the preliminary survey this year, compared to one brood in 1957, 
and two broods in each of 1956 and 1955. 
Production Indices 
Nine stream sections totaling 143 miles have been covered between 
May 22 and June 20, since 1950. A total of 98 wood duck broods was observed 
this year. This figure has been adjusted upward to 106 broods in this report, 
for the following reasons. Water levels were considered satisfactory for 
brood-counts on seven of the nine stream sections. On Jume 10 the Iroquois 
River Section was in flood and one brood was observed. It is believed that 
the adult population observed on this float justifies an estimate of at least 
four broods for this section, which is the previous six-year average. On 
June 12 the Maumee River section was also in flood, and only one brood was 
observed. Again it is believed that the adult population observed, and the 
responses of several flushed females, justifies an estimate of at least siz 
broods for this section, which is also the previous six-year average. 
| The adjusted brood-count of 106 broods is 41.4 percent over 1957, 
and 32.5 percent above the previous six-year average. Whole counts were 
obtained on 67 broods. Brood size averaged 9.7 and ranged from one to 
(Figure 1). 
Brood age distribution for the 98 broods observed indicates thd 
timing of the floats was fair to good, with a slight skewness toward the 
younger age groups: Iea, 8; I-b, 28; I-c, 26; II-a, 23; Il-b, 9; Il-c, 23 
and IIT, none. : 
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