VIREONID^ — THE VIREOS. 371 



Vireosylvia gilvus, vai. swainsoni, Baird. 



WESTEKN WARBLING GREENLET. 



Vireo swainsoni, Baird, Birds N. Am. 1858, 33G (Pacific coast). — Elliot, Illust. Birds 

 N. A. I, vii. Vireosylvia swainsoni, Baird, Rev. Am. B. 343. Vireosylvia gilva, var. 

 swainsoni. Cooper, Orn. Cal. I, 1870, 116. Vireo bartramii, Swainson, F. B. A. II, 

 1831, 235 (in part ; spec, from Columbia River ?). 



(No. 5,321 (J.) Similar to V. gilva, but smaller; colors paler. Bill more depressed. 

 [Jpper mandible almost black. Second quill 

 much shorter than sixth. Total length, 4,75 ; 

 wing, 2.71; tail, 2.35; difference between 

 tenth quill and longest, .58 ; exposed portion 

 of first primary, .58, of second, 1.82, of 

 longest (measured from exposed base of 

 first primary), 2.10; length of bill from 

 forehead, .50, from nostril, .29, along gape, 

 .65; depth of bill, .13; tarsus, .70; middle vireo swamsoiu. 



toe and claw, .56; hind toe and claw, .43. 



Hab. United States, from Rocky Mountains to Pacific coast. 



In the present bird the bill is darker in color, much smaller, and more 

 depressed, the depth at the base being less than the width, instead of being 

 equal to it as in var. gilvus. The wing is more rounded, the second quill 

 much shorter than the sixth, generally shorter or but little longer than the 

 seventh. In var. gilvus, the second quill is about equal to the sixth. The 

 second quill is about .30 of an inch (or more) shorter than the longest in 

 swainsoni, while in gilvus \t is only about .20 shorter. The feet of swainsoni 

 are w^eaker, and the colors generally paler and grayer. The iris, according to 

 Coues, is dark brown. 



Young birds in autumnal plumage have the crown decidedly ash, the sides 

 more greenish ; the wing-coverts pass terminally into a light brownish tint, 

 producing an inconspicuous band. 



Habits. This Western representative of the Warbling Vireo is found 

 throughout the western portions of our Union, from the Great Plains to the 

 Pacific, and from Arizona to the extreme northern boundary of Washington 

 Territory. 



Dr. Cooper characterizes this as a lively and familiar songster. It arrives, 

 he states, at San Diego about April 10, and reaches Puget Sound toward the 

 middle of May, occupying nearly all the intermediate country throughout 

 the summer. It frequents the deciduous trees along the borders of streams 

 and prairies, coming into gardens and orchards with familiar confidence, 

 wherever cultivation has reclaimed the wilderness. Like its Eastern proto- 

 type, its cheerful and varied song is heard all day long until quite late in the 

 autumn. They too build their nests in the shade-trees of. the parks of busy 

 cities, singing ever their delightful strains, unconscious of the busy and noisy 

 crowd that throngs the neighboring streets. 



