1236 U.S. NATIONAL MUSEUM BULLETIN 237 paet 2 



Breeding range. — The western field sparrow breeds from north- 

 western (rarely) and southeastern Montana (Billings, Paris) and 

 northern North Dakota (Charlson, Minnewauken) south to north- 

 eastern Colorado (Boulder, Fort Morgan), western and central south- 

 ern Oklahoma (Arnett, Arbuckle Mountains, Lake Texoma), and 

 Kansas (intergrades in east with S. p. pusilla). 



Winter range. — Winters from Kansas, central Oklahoma (Oklahoma 

 City; Creek County), northern Arkansas (Winslow), and north- 

 western Mississippi (Rosedale) south to northern Coahuila (Sabinas), 

 central Nuevo Le6n (Monterrey), northeastern TamauUpas (Mata- 

 moros), and southeastern Louisiana (Mandeville). 



Casual records. — Casual in migration west to New Mexico (Lea 

 County, Los Alamos) and east to eastern Iowa (Giard) and western 

 Tennessee (Tiptonville, Hickory Withe). 



SPIZELLA WORTHENI WORTHENI Ridgway 



Worthen's Sparrow 



Contributed by J. Dan Webster 



Habits 



It sounded like a chipping sparrow; however, there was a peculiar 

 initial phrase — a slur that was most unchippy-like — and so I investi- 

 gated. The sparrow sang from a waist- high thorny bush, and scrutiny 

 with binoculars convinced me that the bird was one I had been anxious 

 to meet — the little known Worthen's sparrow. This spot where I 

 first encountered the species is still the only one where I have ever 

 seen it, and other recorded localities are few. The only record from 

 the area of the A.O.U. Check-List is the type specimen, which was 

 collected by C. W. Worthen at Silver City, N. Mex., June 16, 1882; 

 otherwise the species has been found only in Mexico. 



There is some doubt as to whether the Worthen's sparrow is distinct 

 from the field sparrow. Burleigh and Lowery (1942) hold that the 

 two are conspecific; whereas Webster and Orr (1954a) argue that 

 they are not. Present information is inadequate for any real conclu- 

 sion. However, the present investigation turned up one more argu- 

 ment in favor of specific status for wortheni, viz.: there is definite 

 sexual dimorphism in plumage coloration in wortheni — more, in fact, 

 than in any other species of the genus Spizella excepting, possibly, 

 atrogularis. Ridgway's (1901) statement, "Sexes alike," is erroneous. 



Ecology. — Brown {in Thayer, 1925) found the species near Miqui- 

 huana, Tamaulipas, breeding in weedy, overgrown cornfields and in 

 prickly shrubs in uncultivated foothills. Ray (in Biu-leigh and 

 Lowery, 1942) collected a specimen in shrubby desert near SaltiUo, 



