882 U.S. NATIONAL MUSEUM BULLETIN 237 part 2 



Oregon: 34 records, May 6 to July 18; 18 records, May 24 to 

 June 14. 



Quebec: 9 records, May 2 to July 11. 

 Wyoming: 14 records, May 30 to July 4. 



POOECETES GRAMINEUS CONFINIS Baird 



Western Vesper Sparrow 

 Contributed by James R. King 



Habits 



The adults of this race of the vesper sparrow are characterized as 

 slightly larger than those of the nominate race, with a more slender 

 bill, and paler, grayer coloration. The streaks on the breast are 

 not so distinct or dark as in P. gramineus. The comparative colora- 

 tion of the Juvenal plumages in P. gramineus sp. is analyzed in 

 detail by R. R. Graber (1955). The principal differences are en- 

 countered in the back and crown: confinis — feathers of the back 

 black, broadly edged with buffy white, crown and back streaked 

 with light brown or buff and black, tertials edged rusty and tipped 

 white; gramineus — similar to confinis but dorsum much darker (no 

 white), crown and back streaked with brown (not buff or Ught brown) 

 and black, tertials edged with brown, not buff. 



The ecology and Hfe history of the vesper sparrows of the West 

 have been studied very infrequently, and the pubUshed reports 

 yield only a fragmentary picture. During the breeding season P. g. 

 confinis is found in open habitats east of the Sierra Nevada-Cascade 

 mountains system from southern Mackenzie south to eastern Cali- 

 fornia, northern Arizona, and northern New Mexico. The breeding 

 range extends eastward to central western Ontario, western Nebraska, 

 and presumably the Dakotas. The western vesper sparrow occupies 

 an extensive altitudinal range within this area, and is typically 

 absent only from the lower dry areas corresponding to the traditional 

 descriptions of the Lower Sonoran Zone and arid Upper Sonoran 

 Zone. This is demonstrated especially well in eastern Washington, 

 where the race is distributed throughout suitable open gi-assland and 

 sagebrush areas except for the arid (annual rainfall less than 10 

 inches) artemisia-agropyron association of the south central Columbia 

 Basin (Daubenmire, 1942; Dumas, 1950; Jewett et al., 1953). 



In eastern California J. Grinnell and A. H. Miller (1944) describe 

 the preferred habitat as "artemisia association in which the sage- 

 brush is well spaced * * * or of no more than moderate height. 

 Much open or sparsely grass-covered ground is required, and this 

 usually is level or gently sloping." In Utah, W. H. Behle (1958) and 



