Notes on the Plumage of North American Sparrows 



TWENTY-NINTH PAPER 

 By FRANK M. CHAPMAN 



(See Frontispiece) 



Worthen's Sparrow (Spizella wortheni, Fig. i). — Few of our birds have 

 a briefer history than this Sparrow. Discovered in 1884, near Silver City, 

 New Mexico, it is still known from very few specimens taken chiefly in Mexico. 

 Doubtless Worthen's Sparrow is a representative of the Field Sparrow, the 

 western form of which it resembles but, as Ridgway remarks, its tail is shorter, 

 the wing-bands less distinct, the sides of the head are gray, and there is no 

 brown postocular streak. There are no specimens of this bird in the Ameri- 

 can Museum, and I can say nothing about its changes of plumage. 



Texas Sparrow (Arremenops rufivirgata, Fig. 2). — Few birds show less 

 change of plumage than does this bush-haunting Sparrow. The male resembles 

 the female; there is practically no difference between the winter and the sum- 

 mer dress, and after the post-juvenal molt the bird of the year cannot be dis- 

 tinguished from its parents. 



The Juvenal, or nestling plumage, however, is strongly streaked with fuscous 

 both above and below. At the post-juvenal molt apparently only the wing- 

 quills and tail-feathers of this plumage are retained, and the bird passes into 

 its first winter plumage, which, as just remarked, resembles that of the adult. 



There appears to be no spring molt, and summer birds differ from winter 

 ones only in being more worn. 



Green-tailed Towhee {Oreospiza chlorura, Figs. 3 and 4). — In this so- 

 called Towhee, the adult male and female are alike in color, and there is 

 essentially no difference between their summer and winter plumages. The 

 young male, also, after the post-juvenal molt, resembles its parents; but the 

 young female (Fig. 3) in corresponding (first winter) plumage has the chestnut 

 crown-cap largely concealed by the grayish tips of the feathers, and the back 

 is grayer than in the adult. 



The Juvenal or nestling plumage is streaked with dusky blackish both 

 above and below. At the post-juvenal molt, only the wing-quills, primary 

 coverts and tail-feathers of this plumage are retained, when the young male, as 

 said above, acquires a plumage resembling that of the adults, while in the young 

 female the crown-cap is absent. 



The prenuptial or spring molt appears to be confined to the throat and 

 anterior parts of the head. Probably the immature female acquires fresh 

 chestnut feathers in the crown, and with the wearing away of the grayish tips 

 of the winter plumage her crown-cap becomes like that of the adult. Aside 

 from this, the summer plumage differs from winter plumage only through the 

 effects of wear and fading, the upper parts being grayer, the flanks paler. 



(35?) 



