884 U.S. NATIONAL MUSEUM BULLETIN 237 part 2 



affinis, describe the eggs as white, speckled and clouded with reddish 

 brown, and report clutches of four to five eggs. 



The measurements of 40 eggs average 20.9 by 15.2 millimeters; 

 the eggs showing the four extremes measure 22.4 by 15.8, 21.8 by 

 16.8, 18.3 by 14.7, and 19.3 by 14-2 milUmeters. 



The food habits of the western vesper sparrow in relation to agri- 

 culture were studied by G. F. Knowlton (1937a,b) and by G. F. 

 Knowlton and W. P. Nye (1948). The insects recognized in stomach 

 analyses were principally injurious forms; the vesper sparrow is cited 

 particularly as a significant predator on the beet leafhopper, 

 Eutettix tenellus (Baker). 



Distribution 



Range. — British Columbia, the prairie provinces, and western 

 Ontario south, east of the Cascades and Sierra Nevada to southern 

 Mexico. 



Breeding range. — The western vesper sparrow breeds from central 

 and northeastern British Columbia (Frangois Lake, Pouce Coupe), 

 southwestern Mackenzie (below Norman, Fort Smith), central 

 Saskatchewan (Dorintosh, Prince Albert), central Manitoba (The 

 Pas, Lake St. Martin, Hillside Beach), and central western Ontario 

 (Wabigoon, Rainy River) south, east of the Cascade Range and the 

 Sierra Nevada, to central eastern California (eastern Tulare County, 

 Inyo Mountains), central Nevada (Toiyabe Mountains), southwestern 

 Utah, central northern and central eastern Arizona (Williams, White 

 Mountains), central western and central northern New Mexico (Zuni 

 Mountains, Santa Fe), eastern Colorado, and western Nebraska; 

 casually north in summer to northwestern Ontario (Favourable Lake) . 



Winter range. — Winters from central California (Fresno, Owens 

 Valley), southern Nevada (St. Thomas), central and southeastern 

 Arizona (Camp Verde, San Carlos), southern New Mexico (Fort 

 Webster, Carlsbad), and southern Texas south to southern Baja 

 California (La Paz), Guerrero (ChUpancingo), and Oaxaca (Tama- 

 zulap am) , casually east to Veracruz (Zacualpilla) , Louisiana (Natchi- 

 toches) , and Mississippi (Saucier) ; in migration to western Kansas. 



POOECETES GRAMINEUS AFFINIS Miller 



Oregon Vesper Sparrow 

 Contributed by James R. King 



Habits 



G. S. Miller, Jr. (1888), describes the adults of this Pacific coastal 

 form of the vesper sparrow as "similar to P. g. conjinis with respect to 

 slender bill and narrow dark dorsal streakings, but dijffering in being 



