ORNITHOLOGICAL NOTES FROM THE WEST. 
BY J. A. ALLEN. 
II. NOTES ON THE BIRDS OF COLORADO. 
Cotorapo Terrirrory embraces portions of two very different 
geographical regions, its eastern half consisting of plains and its 
western being exceedingly mountainous, including several of the 
highest peaks of the Rocky Mountain system. These two regions 
are as diverse faunally as they are in physical features. The orni- 
- thological character of the eastern half of the territory differs lit- 
tle from that of the adjoining portions of Kansas, already briefly 
noticed in the Narurauist for May, p. 263. On entering the moun- 
tains, however, one immediately meets with many species of birds 
not seen on the Plains, whilst only a few of those characteristic of 
the Plains are found in the mountain district, and these only in the 
broad valleys or ‘‘ Parks” which repeat most of the characteristi¢ 
features of the Plains. Owing to the prevalence of forests and 
the highly diversified character of the surface in the western dis- 
trict, the number of species of birds found within it greatly ex- 
ceeds that of the eastern, there being in western Colorado in ce 
breeding season rather more than the average number of spectes 
found during the same season in an equal area of any portion of 
the wooded region to the eastward of the Mississippi River, and 
more than twice the number found in corresponding areas 0n the 
Plains, 
As would naturally be expected, we already find in the narrow 
timber-belts that extend down from the mountains along the 
streams for a short distance into the Plains a few of the wg 
characteristic of the mountains ; just as on the eastern border 
the Plains many of the forest birds of the eastern portion of the 
United States follow up the stream to the farthest limit of yee 
real vegetation. On entering the foothills, however, We are fairy 
within the mountain fauna; and as we advance wes 
mountains. 
tward to the a 
oS) Terese ier eae 
