50 Trans. Acad. Sci. of St. Louis 
Nesting Territories 
Since the publication of Howard’s (1920) now famous book 
on ‘‘Territory in Bird Life’’ no extensive study of a bird is 
complete without considering this important phase. 
Evanston.—The earliest delimiting of territory at Evanston 
was noted February 7, 1926. A male bird, on that date, marked 
out the area as shown in Fig. 1. Only on one border did he 
come into contact with another male and there considerable 
fighting occurred. From a territory such as this a male bird 
will not leave no matter how consistently one annoys him by 
driving him from place to place. His usual relief is to go up 
into flight song. A female was noted with him from time to 
time though she did not persist in the territory. Several other 
birds on the same area, this date, had established song posts and 
territory boundaries. 
There was no method of knowing, at Evanston, whether the 
same territory was retained throughout several nestings because 
of the large number of birds on the area and the consequent 
confusing of individuals. Each large snow storm would destroy 
song posts and disrupt territories and data are not at hand to 
show whether the former territories were returned to when con- 
ditions were favorable, though such is probably the case since it 
proved so at Ithaca. The chief single item in modifying terri- 
tories, once they were established, was the growth of vegetation 
and this in June and July would narrow them down, pinch them 
up or cause their abandonment entirely. 
At Ithaca I forced a male to mark his territory for the 
first time on March 13, though song posts had been established 
some time previously. This was territory ‘‘A’’ (see figure 2). 
Subsequently territories ‘‘B’’ and ‘‘C”’ were plotted as noted 
in figure 2. Of interest is the fact that the territory which the 
male marks when forcibly driven from song post to song post is 
somewhat smaller than that which he will delimit if allowed to 
go voluntarily from place to place. The reverse of this, one 
would think to be the case. Of course not all portions of the 
area are occupied with the same frequency, in fact the bird goes 
but rarely to the remote boundaries. Those regions in juxtaposi- 
tion to the neighboring Lark are, as one might well suppose, the 
positions most frequented, for it is here that limits of the are@ 
must be most rigorously guard 
