8 Rem eg ee ee 
In addition to bag-check and locker-plant examinations by biolo- 
gists, age ratios also were determined in special collections of 
mallard wings from a number of locations. These data are summarized 
in Table 37.2 In many of the special wing collections the individual 
wings were not placed in separate envelopes. Consequently, the 
feather structure was considerably disarranged by blood and by being 
frozen against other wings. Therefore, some of the age and sex 
determinations made from these wings were not as accurate as those 
obtained in the mail wing collection. Mre Eugene DuPont provided a 
sample of 71 mallard wings taken throughout the season in the Atlantic 
Flyway, near Georgetown, South Carolinas These wings showed an age 
ratio of 1.22 immatures per adult, substantially higher than the age 
ratios shown by the wing-collection sample from the southern half of 
the Mississippi Flyway. This suggests that even in the southern 
portions of the Mississippi and Atlantic Flyways there was a trend 
in the direction of ratios going from west to east. 
In the Mississippi Flyway, supplemental wing collections were 
made in a number of locations. In Manitoba, David Olson arranged 
for the collection of 1,407 mallard wings at four different locker 
plants. Only at Winnipeg was the age ratio greater than one immature 
per adult. The higher age ratios at Winnipeg may reflect a tendency 
for age ratios in the east and north to be higher than those farther 
south and west in the same pattern found in Minnesota. In [llinois, 
Frank Bellrose arranged for the collection of wings in the Central 
and Crane Lake Clubs along the Illinois River. The wings showed a 
ratio of 0.44 immature per adult, lowér than the ratio of 0.64 in 
the wing collection sample for the entire State of Illinois. A 
comparison of the data in Tables 35 and 37, however, shows that this 
discrepancy was due chiefly to age-ratio differences in the last 
period, when the collections from the Crane Lake and Central Clubs 
had only 0.27 immature per adult and the State-wide sample had 0.80 
immature per adulte However, in bag cheeks in the same area, Bellrose 
found a still lower age ratio than that observed in the wing collection 
(Bellrose, in a letter of April 8, 1960). 
Wings were collected in five different locations in Arkansas. 
The age ratios in these samples are summarized in Table 37. The 
samples had the same low age ratios as observed in the wing collection 
sample from Arkansase They also suggested a trend toward higher age 
ratios in the northeast corner of the State. The age ratio in the 
special collection of wings from Stuttgart was 0.33 immature per 
adult and the ratio in the wing-collection sample from the same 
vicinity was 0. 27 immature per adult. 
Ps 
