168 AMERICAN ORNITHOLOGY. 



WILSON WARBLER. 



A. O. V. No. 685. (Wllsonia pusilla.) 



RANGE. 



Eastern North America west to the Rockies and breeding from the 

 northern tier of states north to the limit of trees. 



PILEOLATED WARBLER. 



A. O. U- NO. 685a. ( Wilsonia pusilla pileolata.) 



RANGE. 



The Rocky Mountain region and west to the Pacific, breeding north 

 to Alaska. Specimens of the Wilson Warbier which are found on the 

 Pacific Coast and in the Rockies are usually brighter colored than the 

 eastern ones, especially on the forehead, where the yellow is very 

 bright and frequently nearly orange. The habits and nesting habits of 

 the Pileolated or Western Wilson Warbier are the same as those of the 

 eastern birds. 



NEST AND EGGS. 



The eastern form of this warbler nests nearly always if not always 

 on the ground, imbedding their fine grass nests in the moss or leaves 

 under bushes or overhanging banks; the western bird very frequently, 

 perhaps more offen than not, makes its nest just above the ground 

 at elevations of from one to four feet, placing them in low bushes or 

 underbrush on the edge of woods or along the banks of streams. 

 Whether on or above the ground the nest is usually compactly made of 

 grass, rootlets and often leaves, and the cavity is lined with finer grass- 

 es or hair. The eastern bird which usually nests in much higher lati- 

 tudes than the western, generally lays its eggs during June, while the 

 Pileolated variety may be found nesting in the latter part of April or 



May. The eggs of the two varieties are indistinguishable and ränge 

 from three to five in number; they are white finely specked and spotted, 

 chiefly in the form of a wreath about the large end, with reddish brown 

 of several shades. The average size is .60 x .50. 



HABITS. 

 These small sprightly warblers are often known as Wilson's Black- 

 caps or as the Black-capped Flycatching Warblers, this latter name be- 

 cause of their habit of catching insects on the wing after the manner of 

 the true Flycatchers. They winter in Central and northern South 

 America Coming north in the spring so as to reach our southern border 



