SPURRED TOWHEE 589 



gregariousness, and the closeness of the flock depends largely on the 

 size and density of the cover. By about September 21 the post- 

 juvenal molt seems to have been completed, and from then on adults 

 and juveniles cannot be distinguished readily from one another in 

 the field. 



Their winter distribution and activities here seem to be governed to 

 a large degree by the amount and duration of snowfall. Usually the 

 lower west- and south-facing slopes of the Wasatch Mountains are 

 free of snow except for short intervals. However, when the ground 

 is covered for longer periods in midwinter and food becomes difficult 

 to find, the birds tend to drift downward to streamside thickets and 

 other suitable cover along ditchbanks and elsewhere in the lower 

 valleys. Ordinarily no marked wholesale exodus occurs from the 

 summer habitats to the valleys, and some birds may be seen regularly 

 in the foothill brushlands throughout the year. 



From Arizona, J. T. Marshall, Jr., writes us: "We find a few towhees 

 here in winter high in the mountains, and we also have it as an un- 

 conunon winter visitor in the lowlands around Tucson, where it is 

 confined to mesquite woods. On a mountain near Hermosillo, Sonora, 

 where we have never found the bird in summer, we have taken speci- 

 mens in winter up in the oak zone. The most abundant winter 

 population I have seen was in manzanita scattered among oaks at the 

 east base of the Rincon Mountains, where I recorded about 25 in about 

 % mile on January 21, 1951." 



Distribution 



Range. — Eastern California, Utah, and Colorado south to north- 

 western Mexico. 



Breeding range. — The spurred towhee breeds from centra] eastern 

 California (Benton), southern and central eastern Nevada (Grapevine 

 Mountians, Lehman Creek), northern Utah (Stansbury Island, Unita 

 Mountains), and northwestern and central northern Colorado 

 (Boulder) south to southeastern California (Providence Mountains), 

 central western and central southern Arizona (Harquahala Mountains, 

 Baboquivari Mountains), northeastern Sonora (San Jose and San Luis 

 mountains), northwestern Chihuahau (Sierra Madre, south to lat. 

 29° N.), and central southern and northeastern New Mexico (Mesilla 

 Park, Sierra Grande). 



Winter range. — Winters from southern Utah (Beaverdam Moun- 

 tains), central Colorado (Golden), and western Texas (Palo Duro 

 Canyon) south to northern Sonora (Sierra Carrizal, Nacozari) central 

 Chihuahua (Chihuahua), and central Texas (Del Rio, Kendall 

 County) ; casually farther southeast in Texas (Victoria, Eagle Lake). 



