TUCSON SONG SPARROW 1561 



of the plumage. Adults are in heavy molt in September, and first 

 molt may continue until December, but the time of instigation of 

 these molts is not known. Young in juvenal plumages are to be 

 found in September and possibly later. Wear and fading are extreme 

 in the desert subspecies. This is probably due to coarse vegetation, 

 sun, and possibly higher alkaline content of the soils. Adults taken 

 after March are virtually worthless for taxonomic purposes. 



Ridgway (1901) describes jallax as being similar to montana in the 

 slender bill, "but wing and tail averaging decidedly shorter and 

 coloration conspicuously paler and more rusty, the rusty streaks, 

 both above and below, without blackish shaft-streaks, or else with 

 these merely indicated on the interscapular region; young dull brown- 

 ish bufl'y or pale wood brown above, the back streaked with rusty 

 brown or dark brown; beneath buffy white, the chest streaked with 

 rather light brown." 



Winter. — The Tucson song sparrow winters throughout much of its 

 breeding range, but some movement does occur, especially from the 

 northern part of the breeding range. The breeding population at 

 Tucson has been extinct for more than 5 decades, but an occasional 

 winter specimen is taken there, and a winter specimen of jallax has 

 been taken at Bard, Calif. 



Distribution 



Range. — Southeastern Nevada and southwestern Utah south to 

 Arizona and northeastern Sonora. 



Breeding range. — The Tucson song sparrow breeds from south- 

 eastern Nevada (Pahranagat Valley) and southwestern Utah (St. 

 George) south in the Virgin River Valley and the Colorado River 

 Canyon of Nevada and north-central Arizona, and locally through 

 the lowlands of central and southeastern Arizona to northeastern 

 Sonora. It intergrades with saltonis along the Colorado River from 

 southern Nevada to Topock, Arizona, along the Big Sandy River, 

 and a little south of Arlington along the Gila River. In central 

 Arizona it nests below the Mogollon Plateau (Indian Gardens, Oak 

 Creek Canyon, and possibly formerly Walnut Creek north of Pres- 

 cott), along the Verde and Salt Rivers, the Gila River (Geronimo, 

 San Carlos, Safford, Phoenix, Palo Verde), the San Pedro River (near 

 Feldman, formerly south to Fairbank), along the Sante Cruz River 

 (formerly at Tucson), and at Picacho Reservoir. In extreme southern 

 Arizona it has nested at Patagonia and San Bernardino. In Sonora it 

 breeds along the Rio Magdalena (Caborca) and along its tributaries 

 (Rancho la Arizona, Saric, Magdalene, La Casite, and Agua Caliente), 

 along the Rio Sonora (Hermpsillo, Ures, Arizpe), the Rio Moctezum 



646-737 — 68 — pt. 3 21 



