
Wood Duck 
Data for wood ducks could be divided into two portions with 
different age ratios (Table 48). One portion was composed of data 
from the top two tiers of States, excluding Illinois. In the sample 
from this northern portion, the age ratio was 1.74 immatures per 
adult. In the combined sample for the other States, the age ratio 
was 0.96 immature per adult. It is not known whether these differ- 
ences in age ratios reflect differences in production or changes in 
relative vulnerability of the two age groups. Furthermore, the 
sample sizes in each State are too small to estimate the age compo- 
sition of the kill within a State with reasonable accuracy. 
Lesser Scaup 
In most States from which there were large samples, the age ratio 
of the lesser scaup was slightly greater than 1.0 immature per adult 
(Table 49). The average age ratio in samples from Minnesota, Wisconsin 
Michigan, Iowa, Illinois, Indiana, Ohio, and Missouri combined was 
1.28 immatures per adult. In the small sample of 27 lesser scaup 
wings from Arkansas, Tennessee, Louisiana, Mississippi, and Alabama 
combined, the age ratio was 0.42 immature per adult. In bag-check 
samples from Louisiana there were 0.54 immature per adult among 573 
birds (Smith, 1960). 
Table 50 summarizes seasonal changes in age ratios of lesser 
scaup in the two States having the largest samples, Minnesota and 
Wisconsine In samples from both States there was a pronounced pro-~ 
gressive increase in the age ratio as the season progressed. In 
Minnesota, age ratios increased during the first 4 weeks of the 
seasong then declined to a slightly lower level during the remainder 
of the seasone Age ratios in Wisconsin samples increased sharply to 
a peak during the period October 21 through 27, then declined. 
Highest age ratios occurred at the time when scaup made up the 
largest portion of the kill in Minnesota and Wisconsin (Tables 17 
and 18). A possible explanation for the lower age ratios early in 
the season is that non-breeding adults may precede the main flight, 
which then would include relatively more immatures. 
Ring-necked Duck 
Regional differences in ringneck age ratios are shown in Table 5l. 
The highest age ratios were in the samples from the northernmost tier of 
States, (Minnesota, Wisconsin, and Michigan), 1.86 immatures per adult. 
In samples from Iowa, Illinois, and Ohio, the age ratio was 1.04 immatures 
per adult. In samples from the southern half of the Flyway, there was 
0.73 immature per adulte Age ratios in the wing sample from Minnesota 
were examined for various periods during the season to determine if 
there was any change in the ratios as the season progressed. These 
data (Table 52 ) indicated that the ring-necked duck age ratio was 
1.77 during the first 2 weeks of the season, but dropped to 0.55 
immature per adult after October 20. 
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