PASSERINE BIRDS OF NEW YORK 255 



with worn, narrowly streaked breast- feathers shows pin-feathers 

 about the head, throat and back. This bird may be an adult 

 female, but the fact of moult is proved just the same. Young 

 and old become practically indistinguishable. 



5. Adult Winter Plumage acquired by a complete post- 

 nuptial moult in July. Similar to first winter dress but the yel- 

 low richer, and streaked more or less heavily on throat and sides 

 with pale chestnut veiled by the overlapping feather edges. The 

 bill is usually darker. The primary coverts are darker and more 

 conspicuously edged. The crown is not orange or chestnut 

 tinged as in nuptial dress. 



6. Adult Nuptial Plumage acquired by a partial prenuptial 

 moult as in the young bird, from which it is practically indis- 

 tinguishable save in some marked cases by the darker wings and 

 tail most obvious in the primary coverts. The yellowish orange 

 forehead and the chestnut streaks below, heavier than in adult 

 winter dress, are assum(;d at this moult. 



Female. — Not distinguishable until the first winter plumage is 

 assumed, which is paler and lacks the streaking of the male. 

 The first nuptial is assumed by a limited prenuptial moult, be- 

 coming yellower than the previous plumage and acquiring a few 

 obscure chestnut streaks below. The adult winter plumage re- 

 sembles the first winter, but the yellow is deeper and there are a 

 few chestnut streaks below, birds sometimes resembling quite 

 closely males in first winter dress. Later plumages differ little. 



Dendroica caerulescens (Gmel.). Black-throated Blue 



Warbler 



1. Natal Down. No specimen seen. 



2. Juvenal Plumage acquired by a complete postnatal moult. 



Above, including auriculars, olive-brown. Wings dull black, the primaries with a 

 large white blotch basally and edged with bluish plumbeous gray, the 

 secondaries, tertiaries and coverts with olive-green. Tail black with sub- 

 terminal white blotches on the outer rectrices and edged broadly with clear 

 bluish plumbeous gray. Below, dull brownish white, yellow tinged on throat 

 and abdomen. Lores and two submalar streaks dusky ; superciliary stripe 

 yellowish white. Bill and feet pinkish buff, the former becoming black, the 

 latter sepia. 



