2o8 THE PILEOLATED WARBLER. 



No. 84. 

 PILEOLATED WARBLER. 



A. O. U. No. 685 a. Wilsonia pusilla pileolata (Pallas). 



Description. — .Idnlt male: Above bright olive green ; forehead, sides of 

 head, and underparts bright greenish yellow, tinged on sides with olive-green ; 

 crown, or "cap," lustrous black; wings and tail fuscous and olive-edged without 

 peculiar marks; bill dark above, light below; feet light brown. Adult female: 

 Similar, but the black cap wanting, or, if present, less distinct. Immature; l^ike 

 female without cap. Length about 4.75; wing 2.20 (56) ; tail 1.97 (50) ; bill .38 

 (8.5) ; tarsus .75 (18.8). 



Recognition Marks. — Least, — pygmy size; black cap of male distinctive; 

 recognizable in any plumage by small size and greenish yellow coloration. 

 Brighter than ]]'. pusilla ; not so bright as If. /). chryseola. 



Nesting. — As next. 



General Range. — Western North America, breeding thruout the Rocky 

 iNIountain district, north to Alaska, west to Cascade Range in Oregon and Wash- 

 ington and to Vancouver Island ; during migrations over the entire western 

 Llnited States, and east irregularly to the Mississippi ; south in winter over Mexico 

 and Central America. 



Range in Washington. — Not common resident and abundant migrant on 

 East-side ; migrant only west of Cascades. 



Migrations. — Sprhtg: May 1-15. 



Authorities.— Dawson, Auk XIV., 1897, 180. (T). (C&S). D'. Kb. D-'. J. E. 



Specimens.— B. BN. E. P. 



THE pervading yellowness of this little bush-ranger will hardly serve to 

 distinguish it from the equally common Lutescent Warbler, unless you are 

 able to catch sight of its tiny silken crown-patch of black, the "little cap" 

 which gives the bird its Latin-sounding name. With chryseola it is the smallest 

 of our warblers, and it is one of the commonest, during migrations, on the 

 East-side. The thickets have taken on full leaf before the bird arrives from 

 the South, along about the loth of May, and the northward march is often 

 prolonged till the first of June. So expert is the little Black-cap at threading 

 briary tangles, that a meeting here depends upon the bird's caprice rather than 

 the astuteness of the observer. Willow trees are favorite stations during the 

 spring movement, and these because of their scantier foliage afford the best 

 opportunities for study. 



My impression is that the Pileolated Warbler must breed sparingly in 

 eastern Washington. There is, however, only one summer record to substanti- 

 ate this belief, — a bird seen in the valley of the Stehekin, June 22nd, 1906. 

 The only song I have heard dififered from the abruptly terminated crescendo 

 of W. p. chryseola, being rather a well modulated swell, chip chip! chipjf 

 chip!!! chip!!! chip!! chip! chip. 



