July 16 Jwly 2; Aug. 1 aug. 8 Aug. 16 Aug. 2h Total 
to 23 to 31 to 7 to 15 to 23 to 31 
No. of 
pap inrem: 55 17h 122 180 11 26h, 936 
Ze$ 
Small , 60% 45% 15% 5% 2% a 15% 
Medium 27% ey 4 65% 782 70% 79% 65% 
Large 13% 15% 20% 17% 28% 21% 20% 
The continuous low proportion of the large size group is believed to 
be due to the fact that most of the large birds leave the area soon after 
‘they become fully developed (thus reducing the chances of repeat records). 
This belief is supported somewhat by some of the recoveries that were 
reported last year. It is interesting that during the period just before 
the shooting season (Sept. 1) only 21% of the immature birds were in the 
large size category (actually only 14% of immatures trapped during this 
last period were capable of flight). On Aug. 25, 1951, there was an in- 
crease of fully grown young rails in the traps. It is possible that this 
indicates that the first major migration movement was under way at that 
time. 
Molt of Adults 
During the trapping period most of the adults were undergoing their 
post-nuptial molt. During the greater part of this molt these birds are 
completely flightless since the flight feathers are all shed at approxi- 
mately the same time. The individual molting period lasts about one 
month. The first adult observed in full molt was trapped on July 21. 
During the period Aug. 2) to Aug. 31 (period just before hunting season) 
a total of 11 adults were trapped. Of these only 5 had completed their 
_ molt and were capable of flight, while were in heavy molt, and were 
completely flightless. Surprisingly enough the other two adults had 
not even started to molt and were in very worn plumage. It is in- 
teresting that both of these were still accompanied by young (one-third 
grown chicks). The latest of these was observed on Aug. 28. 
Development of Young 
The banding records indicate that it takes about 50 days for the 
young birds to attain full growth and development after hatching. The 
young birds remain with their parents until they are about half grow, 
after which they become independent. The larger young may be dis- 
tinguished from adults by the following characters: Olive-green iris 
instead of orange or orange-brown; bill pinkish-gray instead of orange- 
tinged; legs blackish instead of flesh-colored; much less buffy coloration 
on the breast. Iris begins to change color about the time that the plumage 
of young is fully developed--at this time often appearing olive-brown. 
Adult birds were frequently heard emitting a peculiar grunting sound while 
in the traps. This sound was not heard from young birds until they were 
fully developed. One fully-developed immature Clapper Rail was trapped 
which was abnormally spotted with white. 
57 
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