THE AUK: 



A QUARTERLY JOURNAL OF 



ORNITHOLOGY. 

 vol. xvi. July, 1899. No. 3.. 



SEQUENCE OF PLUMAGES; ILLUSTRATED BY THE 



MYRTLE WARBLER (DENDROICA COROAATA) 



AND THE YELLOW-BREASTED CHAT 



(ICTERIA VIRENS). 



BY JONATHAN DWIGHT JR., M. D. 



Plate III. 



The young birds figured on the accompanying plate illustrate a 

 plumage that is common, not only to all North American War- 

 blers, but to many other species of birds at the time of leaving the 

 nest. It is but one stage in a series, and by tracing the develop- 

 ment of successive plumages in the two species before us, we 

 shall be able to grasp the idea of sequence, which underlies a 

 true understanding of the relation plumages bear to each other. 



There is a downy stage antecedent to the one figured. The 

 young of the Myrtle Warbler (Dendroica coronatd) while in the 

 nest are scantily clothed with downy filaments, the fore-runners 

 of true feathers, which grow from definite parts of the feather 

 tracts. These are rapidly displaced by new feathers, to the tips of 

 which they adhere for some time. This second stage, generally 

 known as the ' first ' or ' nestling ' plumage, in the case of the 

 Myrtle Warbler, happens to bear a strong superficial resemblance 

 to that of the adult Pine Finch (Spin us pinu s) , which is height- 

 ened by the spray of evergreen on which the artist has posed the 

 bird. The plumage of all young birds is, however, always weak 



