the initial coverage. This was due in part 
to less than ideal weather on the first run. 
The late nesting index on the first 
coverage of the five transects totaled 
152 and on July 25 the LNI had declined 
to 78. The conclusion from this that 
although production was late, the coverage 
obtained in July 1965 provides a reason¬ 
able measure of the 1965 production. 
The stratum B area saved the day for 
southern Manitoba in 1965 if estimates 
of production are correct. The 1965 
duck brood index in B was 33 percent 
greater than the 1964 index. Average 
brood size this year was 5. 7 compared 
to the 4. 5 recorded in 1964. The coot 
brood index also increased, being 160 
percent greater than that of 1964. Since 
stratum B is nearly three times the area 
of A the increases in duck and coot pro¬ 
duction found in B have maintained the 
production indexes for the entire south¬ 
ern Manitoba area at levels near those 
of 1964. In reviewing the data for stra¬ 
tum B it was noted that nearly one-third 
of the broods seen were recorded on only 
two segments. This ’’cluster" of broods 
may provide data representative of the 
whole stratum and it may not. Pro¬ 
duction in stratum B may actually be 
poorer than figures indicate and this 
will probably be the case. 
The 1965 index to late nesting for 
strata A and B combined was only 2 per¬ 
cent greater than that found in 1964. 
This modest increase is disappointing in 
view of the very late hatch this year and 
the known near failure of the initial 
nesting effort. The LNI was up a small 
amount in A and down somewhat in B. 
Any late production will find abundant 
brood water available. The survey is 
summarized in tables B-54 and 55. 
MICHIGAN 
Data supplied by Edward J. Mikula 
Michigan Department of Conservation 
Weather and water conditions 
This past winter was considered 
normal for much of Michigan, although 
snowfall was above normal in certain 
areas. Late winter temperatures were 
considerably below normal, and as a re¬ 
sult the ice breakup on the Great Lakes 
and on interior waters was 15 to 35 days 
later than in 1964. The ice breakup date 
for southern lower Michigan was 1 to 3 
days later than the 16-year average date 
of March 14. The migration was delayed 
by the late breakup dates this year. The 
migration peak in southern Michigan was 
10 days later than the 16-year average 
date of March 31. There is evidence to 
indicate that delayed migration resulted 
in an appreciable increase of nesting 
activity by normally non-nesting species. 
Precipitation during the fall, winter, 
and early spring increased water levels 
over much of the State. Water levels on 
the Great Lakes have risen from the near¬ 
record low level of 1964, but much of the 
shoreline breeding habitat is still dry 
and unusable. Available inland waterfowl 
habitat increased from 1964. From the 
standpoint of available breeding habitat, 
1965 is one of the best years since the 
late 1950 f s. Temperatures during the 
nesting season were slightly above normal 
with ideal weather conditions. Nesting 
success was high this year. 
Breeding population indexes 
The potential waterfowl breeding 
population is down from 1964, but still 
ranks among the best (table B-56). 
The percentage of mallards and blue- 
winged teal increased this year while all 
other species showed a decline. 
There was a marked increase in the 
presence of normally non-nesting species 
such as shoveler, pintail, and redhead. 
Brood production appears to have been 
excellent, with brood size above average. 
The number of lone drakes tallied was the 
second highest on record (table B-57). 
Wood duck breeding population was re¬ 
corded as part of the regular breeding pair 
and brood surveys. Many established 
census routes are not in good wood duck 
habitat, so these data are probably on the 
conservative side; they indicate population 
24 
