PASSERINE BIRDS OF NEW YORK 285 



tion not easily answerable. We know that some females in 

 the breeding season are almost indistinguishable from males, 

 and there are all sorts of intermediates from these mature birds 

 down to those of the worn first winter dress, which are guiltless 

 of black. 



Sylvania pusilla (Wils.). Wilson's Warbler 



1. Natal Down. Sepia-brown. 



2. Juvenal Plumage acquired by a complete postnatal moult. 



Above, sepia or hair-brown mottled with sepia. Wings and tail dull olive-brown 



edged with olive-green ; wing coverts paler and indistinctly edged with buff. 



Below, primrose-yeilow washed with pale wood-brown on the throat and sides. 



Bill and feet pinkish buff becoming dusky. 

 Resembles S. mitrata but darker above and on the throat, with paler abdomen ; 



also S. canadensis but with darker, greener edged wings and 'tail ; and easily 



mistaken for G. tri has but less tinged with brown. 



3. First Winter Plumage acquired by a partial postju venal 

 moult, beginning early in July in eastern Canada, which involves 

 the body plumage and the wing coverts, but not the rest of the 

 wings nor the tail. 



Unlike the previous plumage. Above, including wing coverts, bright olive-green 

 the pileum black, veiled more or less with brownish olive-green feather tips. 

 Below, including sides of head and forehead, lemon-yellow, brightest on the 

 superciliary line and orbital ring. 



4. First Nuptial Plumage acquired by a partial prenuptial 

 moult which involves chiefly the head, chin and throat. The 

 clear black cap, sometimes with a few greenish edgings pos- 

 teriorly, is assumed, the structure of the feathers differing from 

 those of the previous plumage, and some yellow feathers are 

 renewed on the throat. The yellow below is resistant to fad- 

 ing, the back becoming grayer. Young and old become indis- 

 tinguishable. Several specimens from Jalapa, Mexico (Am. 

 Mus., Nos. 68553 and 68554), taken in March, show pin- 

 feathers on chin and crown. 



5. Adult Winter Plu.mage acquired by a complete post- 

 nuptial moult in July. Similar to the first v.inter, but the cap 

 clear black, sometimes slightly veiled posteriorly, the yellow 

 below perhaps averaging deeper. 



