70 
Trans. Acad. Sci. of St. Louis 
Some birds leave their nests at such a distance that they cannot 
be seen. However the male usually becomes attentive when the 
female is off and by watching him one —— aware of her. 
4 
(10) 
i 
(16) 
ice 
E 
-— 
ay ~ 
~ 
& 
i 
410 
N 
__200 yards scale _, 
Area: 81.95 acres 
19 
(13) (14) 
1 
(19) (20) 
if 
Fig. 9. Location of the nests of the Prairie Horned Lark on the Main 
real-estate Subdivision at Evanston, Ill, 1926. 
Close attention then to the female may, after an uncomfortably 
long period, di 
disclose the nest when she returns to it. If, for any 
reason, such as activities of farm horses, machinery, workmen, 
ete., near a nest, the female is kept for too long a time from 
it, 
