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NESTING COOTS IN SOUTHERN ILLINOIS: 
A STUDY OF AN ECOSYSTEM 
by DAVID HAYWARD 
To find the American Coot (Fulica 
Americana) nesting in southern 
Illinois is an extremely unusual 
occurance. However, in the last 
half of May and through most of 
June, 1973, coots nested abundant- 
ly in the Mississippi floodplain of 
southern Illinois and Missouri. 
In southern Illinois,. their nest- 
ing was restricted exclusively to 
flooded wheat fields, a_ situation 
best described as precarious. Even 
though observations were sporadic 
and often simply sight records, 
there is enough information to at 
least outline some of the factors 
that influenced their nesting colo- 
nies. Most of my own observations 
refer to a colony of approximately 
100 coots in a region three miles 
southeast of Grand Tower, Jackson 
County. 
In mid-May, during nest con- 
struction, the wheatfields seemed 
ideal for marsh birds. Although the 
floodplain is basically flat, the land 
undulates just enough to have 
gentle valleys and ridges when 
flooded. The wheat (which had 
reached its full height but was 
still green) remained standing on 
the completely dry ridges; between 
the dry sections and open water 
was a strip about three meters 
wide of half-submerged stalks, 
some of them lying flat on the sur- 
face of the water. 
It was in this marshy strip that 
all the coot nests were found. The 
nests were constructed almost com- 
pletely of wheat stalks, many with 
the heads still attached. The only 
other material used were bits of 
driftwood — used sparingly in most 
cases. One typical nest had an en- 
trance ramp sloping up from the 
surface of the water to the rim of 
the nest constructed solely of 
sticks of driftwood. Of 38 nests 
examined on June 1, the average 
number of eggs was 7.8 ranging 
from 5 to 10. On June 1, there were 
about 35 pairs of coots scattered 
throughout the marsh. Most nests 
were attended by one incubating 
adult, while the other adult swam 
or stood nearby. In addition, 25 
coots were seen feeding together 
in a marshy peninsula. 
Fluctuation of the water level 
seemed to be the most potentially 
serious factor that might affect 
their nesting success. On June l, 
(a little more than halfway through 
their 22-23 day incubation period), 
the average water depth at the 
nests was 30.4 cm., ranging from 17 
to 47 cm, June 5, the water had 
risen 3 cm. as a result of the last 
heavy spring rains. However, the 
rims of the nests were still approx- 
imately 4 cm. above water level. It 
is possible that the nests floated a 
little higher due to the rising 
waters, but they were well an- 
chored to and entwined about still- 
standing wheatstalks. 
By June 9, when the young were 
beginning to hatch, the water had 
dropped 9 cm. below the June 1 
level. Although the nests stood out 
more than before, they were still 
all surrounded by water. 
The surface of the marshy sec- 
tion had become clouded with 
floating methane by this time. Af- 
ter hatching time, the water level 
dropped very fast, due to normal 
