299 
Mississippi Flyway 
A comparatively dry spring season and rapid run-off provided excellent 
nesting conditions on the Mud Lake Refuge in northwestern Minnesota, and early 
observations pointed to an increased breeding population. Later Surveys revealed 
a decline of about 25 percent from the 1951 figure. Redheads, scaup, ringnecks, 
canvasbacks and ruddy ducks all showed a decided decrease; the gadwall, a drop 
of 27 percent and the coot production was about 92 percent below last year's figure. 
Mallards, baldpates, pintails, green-winged teals and shovelers each showed 
increases of 100 percent or more over 1951, whereas the blue-winged teals 
dropped 54 percent, 
About 200 miles southeast of Mud Lake the Rice Lake Refuge experienced 
heavy rains throughout the nesting season. As a result of flooding, most of the 
desirable nesting habitat was lost. Only about one-half the number of mallard and 
black duck broods were seen on the refuge when compared to last year's findings. 
Although some pintails nested on the refuge last year, none was observed this year, 
and blue-winged teal and wood ducks were fewer in number. Baldpates, alone, 
showed the only increase in brood numbers, while ring-necked duck counts remained 
about the same, The coot population seemed to be at an all time low. 
On the Tamarac Refuge, weather conditions had a marked influence on nesting. 
All factors considered, everything pointed at first to a successful nesting season. 
However, many of the potholes dried up as the result of a very dry spring, after 
which there were several periods of heavy rain, thus causing temporary loss of 
vital habitat. An added complication was increased predation by skunks and 
raccoons. Mallard production was down slightly from that of last year, ringneck 
production remained about the same, large gains were shown by wood ducks, but 
blue -winged teal and goldeneye production showed a decided decrease. Very few 
gadwall and scaup broods were observed. 
For the first time in several decades, the area originally occupied by the 
Horicon Marsh was reflooded, thus providing an increased area of nesting habitat. 
Possibly this is the reason why blue-winged teal showed an increase in production 
over that of last year, whereas on all other refuges in the Mississippi Flyway, 
except Union Slough, Iowa the blue-winged teal production dropped 30 percent or 
more. The redheads showed some increase at Horicon, while the production of 
other species was close to the 1951 figure. The coots took full advantage of the 
newly flooded marshlands, and their production jumped considerably from that 
recorded for 1951. The most notable event of the nesting season at Horicon was 
that of finding the first brood of baldpates which had been recorded there in recent 
years. 
On the Union Slough Refuge in Mason County, Iowa additional nesting habitat 
became available as a result of development work completed late in 1951. This 
year's waterfowl nesting season was by far the most successful since the establish- 
ment of the refuge. The number of broods, the average size of broods, and the 
total young produced were far greater than the figures recorded last year. Mallards, 
black ducks, pintails, blue-winged teals, shovelers and wood ducks nested on the 
refuge. There was an increase of 98 percent in nesting coots over the number noted 
last year. 
