57 
The preceding graph illustrates the extreme rise in water levels during 1954 
and while levels never did reach the high levels prevalent in May and June 1952, the 
fluctuation was much greater and caused considerable flooding of nests. Water 
levels were about equal on June 30 for all three years and actually lower on August 1 
for the past two years than in 1952. However, water levels do not indicate actual 
conditions as regards brooding cover and vegetative growth in general. Low water 
levels in May of 1953 and 1954 encouraged germination of emergent aquatic plants 
so that emergent cover which developed during the summer was much more abundant 
in 1953 and tremendously more so in 1954. Then,too, water levels were 11 inches 
higher on August 1, 1954 than they were on May 1 or on June 1 and this meant that 
much of the emergent aquatic vegetation was still standing in from several inches to 
a foot or more of water in 1954, whereas, in 1952 many areas had dried up com- 
pletely or water had receded from vegetation-lined shores by late July. 
Water Areas 
The percentages of water areas occurring during the four coverages during 
the three-year period are shown on Table I. 
Table I. - Water Area Data, 1952-1954 - Number of Areas Containing Water 
on Bach Coverage* 

1952 1953 1954 
Mid-May 306 (100) 306 (100) 232 ( 76) 
First week in June 244 ( 80) 306 (100) 252 ( 82) 
Mid -July 253 (83) 276 (90) 338 (110) 
Late July - August 181 ( 59) 214 (70) 265 = ( 87) 
* Based on 306 water areas considered to be normal for the area. 
Figures in parenthesis are percentages. 
Thus although water levels on semi-permanent areas were 7 inches higher on 
August 1, 1952 than they were on the same date in 1954, there were almost 60 percent 
more areas on August 1, in 1954 due to frequent rainfall in late July which kept 
shallow areas from drying up. 
The Breeding Population 
Two censuses of breeding pairs were made each year, the first beginning 
May 10, and second about three weeks later during the first week in June. Results 
are as follows: 
