CENTRAL FLYWAY 
the rapidly dropping water levels. At the time of the mid -July brood 
survey there were 40 percent fewer water areas (other than streams) 
east of the Missouri River than there was at the same time in 1953. 
This reduction in mid-July water area density was general over the 
eastern part of the State, averaging 47 percent in the Minnesota Valley, 
34 percent in the Prairie Hills, 46 percent in the James River Valley, 
and 33 percent in the Missouri Hills. 
Breeding Population Indices - 
The decrease in water levels was accompanied by a 21 percent 
decrease in the breeding waterfowl population. The minimum State- 
wide duck density was estimated to be 10.85 ducks per square mile, 
compared with 13.72 per square mile in 1953. The current duck 
density is about the same (4% greater) as the 1950-1953, 4-year 
average density of 10.40 birds per square mile and represents a 
minimum population of 811,000 ducks. Coots decreased in abundance 
about 42 percent below their 1953 level. (Table I.) 
Production Indices ~ 
Despite the reductions in breeding populations and water levels, 
the east-river brood survey in mid-July indicated a duck brood 
density comparable to that of mid-July in 1953, An average of 0.65 
broods per square mile was observed in the east-river country which 
is 8 percent below the 0.71 brood per square mile density in 1953. 
The distribution of broods, however, was considerably different than 
in 1953, The extreme eastern part of the State had a considerably 
higher brood density, especially in the north. In the Prairie Hills 
the density was 39 percent above that of 1953. The western portion 
of the east-river country contained substantially fewer broods than 
1953, averaging 60 percent less in the Missouri Hills and 36 percent 
less in the James River Valley. 
Table II - Indices to Duck Brood and Water Area Densities in mid-July, 
a 1954 and 1953-1954 Trends 
— Duck Broods Water Areas * 
Physiographic ' Per Sq. Mi. Percent Per. Sq. Mi. Percent 
Division -° 1953 1954 Change 1953 1954 Change 
Minnesota Valley 0.00 0.33 3 4+ 3.33 1.78 - 47 
Prairie Hills 1.04 1.45 + 39 £4.59 3.05 = 34 
James R. Valley 0.72 0.46 - 36 3.81 2.07 ~ 46 
Missouri Hills © 0.48 0.19 - 60 2.57 1.71 - 33 
East-River Total 0.71 0.65 - 8 3.72 2.23 - 40 
* Total water areas excluding streams. 
41 
