366 BULLETIN 191, UNITED STATES NATIONAL MUSEUM 



but the white stripe over the eye is more imperfect, less distinct, and 

 grayer; the black of the crown and throat is duller; and the edgings 

 of the greater wing coverts and tertials are tinged with pale buff. The 

 body plumage is softer and fluffier, less compact. The annual molt 

 seems to occur mainly in August, though I have seen very few molting 

 birds. Fall birds have the white superciliary stripe broader and more 

 distinct, and the gray portions of the plumage slightly more bufify 

 than in spring birds; in spring birds the superciliary stripe is reduced 

 to a broken series of white streaks. 



Voice. — Aretas A. Saunders sends me the following note on the song 

 of this chickadee, as heard by him in Montana: "The song of the moun- 

 tain chickadee is similar in quality to that of the black-capped cjiickadee, 

 a sweet, clear whistle, but it usually consists of three notes of equal 

 length, each lower in pitch than the preceding, so that it is like fce- 

 bee-hay. The bird occasionally responds to an imitation and comes 

 to the observer, but not so readily as the black-cap does. The song 

 is rather infrequently used." 



Claude T. Barnes says in his notes : "Two c.hickadees, which from 

 the white superciliary stripe I took to be ganiheli, flitted about the maple 

 trees uttering every second or so a single note chip. Once in a while 

 one would issue a burring sound like trrrrrrrrrp. Overcome with 

 curiosity at my immobility, they edged their way by little flits and 

 various maneuvers behind tree trunks until they were within six feet 

 of me, when, evidently being satisfied, they as casually worked their way 

 from me." 



Edward R. Warren (1916) writes: "They seemed to say 'chick-a-dee- 

 a-dee-a-dee', not 'chick-a-dee-dee' as the Black-caps do. And the tone 

 was also different, but I cannot describe it." 



Field v.iarks. — Although similar in general appearance and behavior 

 to our more familiar black-capped chickadees, this species can be easily 

 recognized by the usually conspicuous white stripe that runs from the 

 bill over the eye and into the black cap. Its song is different, as de- 

 scribed above, and its ordinary chickadee note is somewhat hoarser and 

 more deliberate. Also, it is oftener found in the coniferous forests than 

 is atricapillus. 



DISTRIBUTION 



Range. — Mountains of the Western United States, Canada, and 

 northern Baja California; nonmigratory. 



The range of the mountain chickadee extends north to northern 

 British Columbia (Atlin and Nine Mile Mountain) ; Alberta (Smoky 

 Valley and Banff) ; and central Montana (Gold Run and Fort Custer). 



