Reproduction 
150 yards. 
49 
with larger territories, sang even farther away, frequently at 
Summary.—The song of the Prairie Horned Lark is, all in 
all, one of the most remarkable activities in the bird world. 
With a season from January to July, an optimum in May, a 
8:00 P. M. (in June), a flight 
daily period from 4:00 A. M. to 8: 
song with an average height near 500 feet, two types of delivery 
on the ground or in the air, and an evening’s vesper that out- 
lasts all others—it becomes an exhibition above challenge. 
=a 
50 yards scale 
Fc! Se cole 
pa fae 
: 
_-fmound s 
or” = 
P . ‘ 
a : 2 e 
Z % 
‘4 Pri 
4 
A 
i 6 
ul 
' 
' 
‘ 
‘ 
' 
' 
’ 
t 
: 
‘4 
———_—_" 
ieee - 
m; 
7 Streetway 
Soe 
a 
. 
. 
— 
ee ae 
TF 
ie, 
pea all 
See eee 
~~ 
peda 
: Bong post 
of nearest 
Lark neigh- 
bor 
* 
~~ 
a Potead katel 
. ~~son osts. 
suber’ indicate 
rder of prefer- 
————— 
ence. 
territory boundary 
orned Lark, Feb. 7, 1926, at 
date. 
Fig. 1. The territory of a male Prairie H A 
Evanston, Ill., as marked out by the song posts of tha 
