PLATE XV 
FLUCTUATIONS IN MOBILITY 
OF CANVASBACK BROODS 
' 
MTT MI 
Potetete’ 
"ete: 
5 
+, 
a 
OL Mot At gh held 
PM dd ded dl 
ornnuil 
Se 
ty 
OOOX 
TLL 
er eTe TOT 
MOBILITY RATING OF BROODS 

O Eze 
DATE 6/I8 6/23 6/28 V3 78 IS WIS Yes 728 8/2 8/7 S8/l2 8/IT 872i 
HEAVY HEAVY 
RAIN RAIN 
dal }_— FALLING ————_—__+ FALLING ——-} 
FALLING 
yj, BASED ON LESS THAN 5 BROODS 
SY BROODS FLYING 
E=] BROODS HATCHING 
