PASSERINE BIRDS OF NEW YORK 83 



stores the worn-out plumage, the second (when it is not sup- 

 pressed), the pre-nuptial, adorns birds for the nuptial season. In 

 a few of our species the latter moult is complete, usually the 

 wings and tail are not involved, and often the renewal is limited 

 to a sprinkling of new feathers here and there, so limited, in fact, 

 that it sometimes becomes a difficult matter to draw the line be- 

 tween a moult and the regular tendency, in nearly all species, at 

 this season, to the renewal of a few feathers. A limited, or sup- 

 pressed, pre-nuptial moult is peculiar to many females, while the 

 males may undergo an extensive renewal, and young birds of 

 some species undergo a pre-nuptial moult once, that is appar- 

 ently not repeated another year. There are also several moults 

 peculiar to young birds before they even acquire feathers of adult 

 structure, and many species need to pass through at least two 

 moults besides those of the first summer before the plumage be- 

 comes wholly of the pattern and color of the adult. With all of 

 these possibilities it is easy to understand, I think, why the 

 moult has been considered complicated. In reality it is the re- 

 sulting plumages that are perplexing rather than the moults by 

 which they have been produced. Closely allied species may 

 not moult alike but it is evident that subspecies follow in the 

 footsteps of the parent stock. 



On account of certain irregularities and peculiarities in the 

 moult of young birds, I have deemed it best to describe first the 

 process of moult as it occurs in the adult and take up that of the 

 young bird later. 



Protective Sequence in Feather Loss. 



The feather loss at the time of a moult is so compensated for 

 by feather gain that but few birds lose either the power of flight 

 or the protection of their plumage. The plan on which a moult 

 proceeds is a perfectly definite one although often much modified 

 and obscured. Old feathers or rows of feathers tend to remain 

 until the newcomers adjacent have matured sufficiently to as- 

 sume their function, when the old fall out and their places are 

 taken by the new which develop from the same papillae. How 



