30 
resulted in 4 inches of rain in 2 days 
being reported at the Seney Refuge. Lake 
levels have declined throughout the State, 
and they average from 3 to 6 inches below 
the 15-year median. 
The weather during April, May, and June 
has been conducive to a good breeding season 
with above-normal temperatures for the- 
most part and less-than-normal precipita- 
tion. 
BREEDING POPULATION INDEXES 
The percentage species composition of the 
duck breeding population for 1960 and 1961 
is givenintable E-29 (p. 100). The potential 
breeding population compared with those of 
previous years is presented in table E-30, 
Potential breeding wood ducks were 
counted during regular census trips. It 
Should be understood that the observations 
made on the wood ducks are obtained in 
conjunction with observations on other 
species. No special study areas are set 
up for wood ducks and the areas censused 
do not contain very much of what is con- 
sidered to be ideal wood duck habitat. 
The number of potential breeding ducks 
seen per lineal mile of census route was 
the highest of the past 10 years, and the 
potential wood duck breeding population 
was the second highest, surpassed only in 
1953. Wood ducks made up 4.8 percent of 
the local nesting species. This figure 
compares favorably with the average of 
past years. 
PRODUCTION INDEXES 
The number of broods observed per lineal 
mile in 1961 was one of the highest of the 
past 10 years, second only to that of 1952. 
Brood size was about average. The number 
of lone drakes observed was considerably 
lower than in the past 2 years, leading us 
to believe that a good percentage of the 
nesting birds were successful. The results 
of the production survey are presented in 
table F-31 (p. 121). 
CONCLUSIONS | 
A record number of potential breeders 
were on hand and withthe favorable weather 
conditions, apparently a high percentage 
of thern nested. Subsequent data from brood 
counts lead us to believe that 1961 has been 
a good waterfowl production year in Michi- 
gan, ranking well above the average of the 
past 10 years. 
IOWA 
Data supplied by James G. Sieh, 
Iowa State 
Conservation Commission 
WEATHER AND WATER CONDITIONS 
Most of Iowa's prairie marshes and 
shallow lakes were dry or almost dry 
during 1957, 1958, and 1959. This drought 
period caused rapid re-vegetation of these 
areas with emergent aquatic plant species. 
Heavy runoff and above normal rainfall 
during the spring of 1960 inundated many 
sloughs, ponds, and potholes that had been 
dry. Runoff during the spring of 1961 
increased the water levels in many areas 
and inundated additional dry habitats. These 
circumstances have caused optimum nest- 
ing and survival conditions for waterfowl 
in Iowa during 1961. Habitat and phenologi- 
cal conditions suitable for waterfowl pro- 
duction and survival appear the very best 
observed during 12 years of continuous 
study in northwestern Iowa, and conditions 
are likewise excellent throughout the State. 
PRODUCTION INDEXES 
Iowa is producing unusually large num- 
bers of blue-winged teal, wood duck, ruddy 
duck, and redhead. The nesting effort and 
success of each of these four species 
appears of such magnitude that total pro- 
duction should be of significance to the 
Flyway in 1961. Both mallards and pintails 
are abundant for Iowa, but their total 
numbers are too few to be of importance 
on a Flyway basis. Other species of water- 
fowl are present, but their aggregate num- 
bers are also not significant. 
Coot production is far above normal. The 
nesting densities of this species inrecently 
flooded habitats is trernendous and pro- 
duction is greater than had been expected. 
Broods are beginning to appear, and 
nesting success based upon a few early 
observations looks encouraging. Vegetation 
