238 U. S. NATIONAL MUSEUM BULLETIN 211 



some in which cotton thread and twine were component parts of its elastic and 

 firm structure. The nests are of various lengths, conformable to the material 

 at hand for the intricate formation of the warp necessary for the weaving of 

 this unique and airy abode, in which to rear their little family. The inside bot- 

 tom is lined with the downy substance of the tree cotton, intermixed with a few 

 feathers. In one nest I found an entire skein of yellow silk, which it had doubtless 

 picked up where some village brunette had dropped it. 



The eggs are generally five in number, rather long, of a pale blue ground, with 

 numerous hieroglyphic scratches confluent around the larger end. 



Plumages. — I have seen no small young of the scarlet-headed 

 oriole, but Ridgway (1902) describes the young as "similar to the 

 winter female, but without any black on throat, etc.; streaks on back 

 obsolete, and colors duller. * * * Immature males resemble adult 

 females in coloration." I have seen first winter birds, with the gray 

 backs, taken in October, January, and March, and one as late as 

 June 2. 



He describes the adult male in winter plumage as "similar to the 

 summer plumage, but white edgings to wing feathers much broader, 

 often strongly tinged with gray; orange or yellow of back, rump, 

 etc., more or less tinged with olive, the back often tinged or suffused 

 with gray." 



He says of the winter plumage of the adult female: "Similar to the 

 summer plumage, but upper parts much tinged with gray, especially 

 on back, and grayish white or light gray wing-edgings broader." 



Enemies. — Friedmaim (1933) mentions several instances of the 

 bronzed cowbird (T. a. aeneus) laying its eggs in nests of this oriole. 



DISTRIBUTION 



Range. — The western scarlet-headed oriole is resident from central 

 Sonora (Hermosillo, Ures), southwestern Chihuahua, western Du- 

 rango, and Jalisco (Bolanos, Guadalajara) ; south to Sinaloa (Mazatlan, 

 Escuinapa), Nayarit (San Bias, Topic), and Jalisco (Barranca Ibarra, 

 Zacoalco). 



Casual records. — Accidental in California (La Mesa) and Arizona 

 (Tucson). 



