24, BIRDS OF THE ROCKIES 



purpose he must have frequent recourse to the useful 

 manuals of Coues and Ridgway, and to the invaluable 

 brochure of Professor Wells W. Cooke on the " Birds 

 of Colorado. 1 ' In passing, it may be said that the last- 

 named gentleman might almost be called the Colorado 

 Audubon or Wilson. 



In studying the birds of the West, one should note 

 that there are western subspecies and varieties, which 

 differ in some respects, though not materially, from their 

 eastern cousins; for instance, the western robin, the 

 western chipping sparrow, the western lark sparrow, and 

 the western nighthawk. Besides, intermediate forms 

 are to be met with and classified, the eastern types shad- 

 ing off in a very interesting process into the western. It 

 would be impossible for any one but a systematist with 

 the birds in hand to determine where the intermediate 

 forms become either typical easterners or typical 

 westerners. 



Most interesting of all to the rambler on avian lore 

 intent is the fact that there are many species and genera 

 that are peculiar to the West, and therefore new to him, 

 keeping him constantly on the qui vive. In Colorado 

 you will look in vain for the common blue jay, so abun- 

 dant in all parts of the East ; but you will be more than 

 compensated by the presence of seven other species 

 of the jay household. The woodpeckers of the West 

 (with one exception) are different from those of the 



