
234 
WATERFOWL BREEDING GROUND SURVEY ~ IOWA, 1954 
James G. Sieh 
Introduction 
Breeding pair and brood studies have been carried on during routine 
on-the-sport check counts in the prairie marsh areas of northwestern Iowa since 
1949 to evaluate the trend of nesting waterfowl other than wood ducks. Wood duck 
stream surveys were begun in. 1953 and repeated in 1954 in an attempt to determine 
wood duck production trends (see Figure 1}. Wood duck nesting box checks have 
been completed on the Lake Odessa area in Louisa County to determine nesting box 
utilization and to evaluate production each year since 1950 (Table I). Random 
nesting box checks have been made intermittently in northwest lowa since 1949, 
Aerial survey of the prairie marshes was begun in northwest Iowa using a 
lineal census technique which was modified in 1953 and 1954 to attempt total counts 
on individual lakes, sloughs, and marshes. 
Spring Migration 
Migrating mallards and pintails arrived in the lakes regin of northwestern 
Iowa with warm southerly winds of a frmtal system moving into and across Iowa on 
March 16,1954. Ten days later concentrations of redheads and smaller numbers of 
canvasback were present in the lakes region, and by April 5 peak numbers of divers, 
especially lesser scaup and ring-necked duck, were present. Extremely warm 
temperatures in early April and unusually cold, freezing weather in early May 
probably accounted for the large concentrations of blue-winged teal in the State. 
Large shifts of migrants through the lakes region have not been'recorded since 1942, 
and the large increases in 1954 bring to mind increases in migratory numbers 
reminiscent of, but not equal to migrant numbers recorded in the early thirties. 
Waterfowl Production 
On-the-spot check counts in the prairie marshes of northwest lowa each 
spring and summer since 1949, plus aerial coverage of the same marsh units since 
1952, have provided a studied opinion as to the production trends of blue-winged teal 
and mallards. Blue-winged teal constitute the most numerous nesting species in the 
remaining prairie marshes, and the mallard is not far behind. Production of these 
two species in 1954 remained about the same as in 1952 or 1953 with no appreciable 
change in nesting numbers. With the exception of increased production in 1951 which 
