SONORA REDWING 177 



DISTRIBUTION 



The San Diego redwing is resident in southwestern California 

 (Santa Margarita, Redlands, Jacumha) and northwestern Baja 

 California (Sierra Juarez, El Valle de la Trinidad, El Rosario). It is 

 casual in winter in southeastern California (Imperial). 



AGELAIUS PHOENICEUS SONORIENSIS Ridgway 



Sonora Redwing 

 HABITS 



A. J. van Rossem (1926) describes the Sonora redwing as being — 



Of the slender-billed sonoriensis-nevadensis-caurinus chain. Bill longer and 

 more slender than in nevadensis and of different shape than in caurinus. Males 

 with middle wing coverts more often and more extensively marked with black 

 than in nevadensis, and therefore not to be confused in this respect with caurinus 

 which is, except in the extreme southwest corner of its range, essentially an im- 

 maculate buff-winged form. Pale tipping of feathers in fall plumage more exten- 

 sive and paler than in the other California races, and very frequently persisting 

 (even in fully adult males) on the interscapular region until the bird is in worn 

 (late May) plumage. Females by far the palest of the California races. Paler 

 and with narrower ventral streaking than in nevadensis; paler and less buffy than 

 in caurinus, with markings more diffused (less contrasted) than in that form. * * * 



After examining the type, a young female in first winter plumage 

 taken at Camp Grant, 60 miles east of Tucson, Ariz., February 10, 

 1867, van Rossem concludes: 



This locality is east of the established breeding range of sonoriensis as now under- 

 stood and in a region occupied by both fortis and nevadensis in winter. Mr. 

 Ridgway [1902] himself gives the type locality as "Mazatlan, w. Mexico." It is 

 unfortunate that the type was not selected from the latter locality, for Mazatlan 

 birds are essentially the same as Colorado River valley specimens. In color, the 

 type is not quite like the average from the metropolis of the race and its bill is 

 shorter than any other female sonoriensis so far examined. It recalls certain 

 young females of fortis in some particulars and its identity may yet be shown to 

 lie in that direction. However, the case demands further material for final 

 solution and I continue to apply the name, for the present, to the birds inhabiting 

 the lower Colorado River and its tributaries and the coastal districts of Sonora 

 and Sinaloa. 



E. W. Nelson (1900) was the first to call attention to the un- 

 fortunate selection of a type for what we now call sonoriensis; his 

 paper throws some light on what has caused considerable confusion 

 as to the propriety of the name, as well as to the distribution of the 

 subspecies. 



