Percent 
80 
60 ' 
40 
20 
80 
60 
40 
20 
BO 
a 
are 
@ 
0 
8) 
May 20 

June 19 July 19 Aug. 18 Sept. 17 
(3.2 broods 
per sq. mile) 
(2.6 broods 
per sq. mile 
(5.1 broods 
per sq. mile) 
(3.5 broods 
per sq. mile) 


Oct. 17 Nov. 16 
Figure 15.--GADWALL: FLIGHTLESS BROODS, EXPRESSED AS A PERCENTAGE 
OF ALL GADWALL BROODS PRODUCED , 1950-53 
[See text for explanation of these graphs] 
31 
