MOUNTAIN WHITE-CROWNED SPARROW 1343 



As the sets of oriantha eggs were taken over many years at many 

 different latitudes, other variables may mask the altitudinal effect. 



Distribution 



Range. — Southern Saskatchewan and Alberta to Baja California 

 and central Mexico. 



Breeding range. — This race intergrades with gambelii from north- 

 western Alberta in the Canadian Rockies to Glacier Park, Montana. 

 An isolated population breeds in the Cypress Hills region of south- 

 western Saskatchewan and southeastern Alberta. The Mountain 

 White-Crowned Sparrow breeds from western Alberta (Gorge Creek, 

 Bragg's Creek, Banff National Park) to northern Idaho (Continental 

 Mountain) south to eastern Oregon (Wallowa Mountains), southwest 

 through central and southern Oregon (Harney, Hart Mountain, Adel) 

 to northeastern California (Warner Mountains). Isolated popula- 

 tions occur in the Cascades of west central Oregon (Three Sisters, 

 Tumalo Creek, Crescent Lake) and of California (Bray, King's Creek 

 Meadows in Lassen National Park). From the Warner Mountains 

 the range in California extends southward through the Sierra Nevadas 

 (Mohawk, Plumas County to Horse Meadow, Tulare County). Iso- 

 lated colonies breed in southern California (San Bernardino Moun- 

 tains) and in eastern California in the White and Sweetwater Moun- 

 tains, and on peaks in Nevada (Ruby Mountains and Jarbridge 

 Mountains). The boundary of the range continues through south- 

 ern Utah (Cedar City, Kanab area, Bluff) to northern New Mexico 

 (Pecos Baldy, Wheeler Peak) through central Colorado (Mount Ptar- 

 migan, Colorado Springs, Boulder County, and Northgate) to Wyo- 

 ming (Sierra Madre Mountains, Albany County, Fort Steele, Muddy 

 Creek, Beartooth Plateau) and north through central Montana 

 (Shriver) and on isolated mountain ranges (Crazy Mountains, Big 

 Snowy Mountains, Little Belt Mountains, Big Belt Mountains) to 

 Saint Mary's Lake. 



Winter range. — Winters from southern California (casually to Los 

 Angeles area, and Twenty-nine Palms; Coachella, Holtville), east to 

 southern Arizona (Gila Bend; Pinal County), east to southern New 

 Mexico (Silver City), and western and Central Texas (Frijole in Cul- 

 berson County; Concho County; Kerr County); south to southern 

 Baja California (San Jose del Cabo) ; south and east through Sonora, 

 Sinaloa, Coahuila (Sabinas; Hipolito), Nuevo Leon (Monterrey), 

 Aguascalientes (Aguascalientes), San Luis Potosi (Rio Verde), Guana- 

 juato, Queretaro (San Juan del Rio); south to Jalisco (Atoyac; Ocot- 

 lan), and Michoacan (Patzcuaro). 



Migration. — Early dates of spring arrival are: Colorado — Salida, 

 April 19; Sulphur Springs, May 2. Montana — Gallatin County 



