Notes on the Plumage of North American Birds 



THIRTY-SECOND PAPER 



By FRANK M. CHAPMAN 



(See frontispiece) 



Kennicott's Willow Warbler {Acanthopneustc boreal is. Fig. u). 

 This, our only representative of the Old World Warblers, is found in North 

 America only on the coast of Alaska. The sexes are alike in color, and there 

 is practically no variation with age or season. I lack material with which to 

 determine the character of the molt. 



Ruby-Crowned Kinglet {Regulus calendula. Figs. 2 and 3). Wholly 

 aside from the differences in the color of the crown, the Kinglets may be dis- 

 tinguished by the markings about their eyes. The Golden-crown always has 

 a distinct whitish stripe above the eye, while the Ruby-crown has a well- 

 marked whitish eye-ring. These characters make excellent field-marks. 



In nestling plumage, the Ruby-crown is dusky oUve above, grayish white 

 Ijelow, with no trace of the red crown-patch. This mark is acquired by the male 

 at the post-juvenal molt, after which the young resembles the adult. There 

 is no spring molt, and summer birds differ from winter ones only in being some- 

 what grayer. The female resembles the male, but never has the 'ruby' crown. 

 It follows, therefore, that (excepting nestlings) all the Ruby-crowns seen with 

 the crown-patch are males, and all those without it are females. 



The Sitkan Kinglet {R. c. grinnelli) breeds in the Sitkan region of Alaska, 

 and migrates southward to California in winter. Like many other forms of 

 this region, it is more richly colored than its eastern representative. 



The Dusky Kinglet {R. c. obscurus) is a strongly marked race, which inhab- 

 its Guadeloupe Island, off the Pacific coast of Lower California. It is decidedly 

 darker, less olivaceous than the other forms of this species. 



Golden-crowned Kinglet {Regulus satrapa. Figs. 4 and 5). As the 

 plate clearly shows, the male Golden-crown differs from the female in having 

 the center of the crown flame-orange, instead of yellow. The nestling has no 

 crown-patch whatever, and both above and below is duskier than the adult. 

 The wings and tail, which are retained at the post-juvenal (first fall) molt, 

 resemble those of the adult. At this molt the male acquires his orange, yellow 

 and black crown, the female hers of yellow and black. This brings the birds 

 into their first winter plumage, in which they resembles the adult. 



There is no spring molt, and the summer plumage does not differ materially 

 from that worn in winter. 



The Western Golden-crowned Kinglet {R. s. olivaceous) of the Pacific coast 

 region, closely resembles the eastern race, but is more hrightlv colored. 



(126) 



