Scott on Birds of Western Missouri. 3 39 
only does not keep pace relatively with its development in other 
respects, but appears to become even slightly shorter. Thus aver- 
age specimens of pallasi have the tarsi as long as the larger individ- 
uals of auduboni , while a few of pallasi exceed in length of tarsus 
any of auduboni. No cause for this appears to suggest itself. 
Nor is it easy to understand why a mountain environment, in 
the case of auduboni , should have resulted in what seems to be 
a natural enough change, namely, increase of size, while the very 
reverse is true of nanus , which is as essentially a bird of the moun- 
tains as its ally. 
It has been remarked before as an apparent exception to a general 
rule that specimens of auduboni from Mexico, towards the southern 
limits of its distribution, are no smaller than those from the Northern 
Rocky Mountains. All the specimens from Mexico that I have 
been able to find in the Smithsonian collection were taken in winter, 
and hence it has occurred to me they may not represent the resi- 
dent type , but may be migrants from more northern localities, and 
hence not eligible in a comparison of this kind. A few summer 
specimens would, of course, settle all doubt. 
NOTES ON BIRDS OBSERVED DURING THE SPRING 
MIGRATION IN WESTERN MISSOURI. 
BY W. E. D. SCOTT. 
Warrensburg, the point at which the following observations 
were made, is about sixty miles southeast of Kansas City in Johnson 
County. The surrounding country is rolling prairie, well watered 
by several streams. Along these streams the timber is abundant, 
and frequently forms on either bank forests of considerable extent. 
The fauna and flora of the region are both Carolinian in their main 
features, but the change in temperature from severe cold to extreme 
heat is greater than in New Jersey, Being from about — 20° 
Fahrenheit in winter to +100° in the summer. The winters, with 
exceptions of the severe cold snaps which last only one day or more, 
are much milder than at the point indicated on the Atlantic coast, 
and the snow-fall is very slight. 
The spring of 1874, when the observations that follow were made, 
