THE BLACK GUILLEMOT. 



803 



with much wider white tips often entirely obscuring black (white 

 fringes vary in width and rarely are almost absent from mantle, 

 and usually absent from longest upper tail-coverts) ; under-parts 

 white but dark brown bases of feathers of base of throat, sides of 

 breast and flanks not entirely concealed ; axillaries white and most 

 of under wing-coverts but those round edge of wing black-brown ; 

 tail black ; primaries and secondaries with outer webs and tips 

 black, inner webs brown with basal inner part white ; primary- 

 coverts, coverts along edge of wing, lesser coverts and innermost 

 median and greater black, rest of median and greater white forming 

 large patch in middle of wing. This plumage is acquired by complete 

 moult beginning sometimes July and occasionally not complete 

 Dec. Primaries, secondaries, tail, primary-coverts, greater coverts 



Wings of the Black Guillemot (Vria g. grylle). A. Adult. B. First winter. 



and two lower series of median coverts are moulted, as in other 

 " Auks,*' in series simultaneously, primaries and secondaries usually 

 first and tail usually last. Summer. — The body -feathers are again 

 moulted Jan.-March (occasionally Dec. and April), whole head and 

 body brown-black, browner on under-parts, all glossed greenish 

 when fresh but becoming duller and browner by wear ; wings and 

 tail as winter. 



Nestling (Plate 11). — Closely covered with soft down with 

 silky tips. Uniform rich black-brown, paler shade on under-parts; 

 Down is replaced by juvenile feathers to tips of which it clings. 



Juvenile. — Upper-parts browner than adult winter and with 

 less white, centre of fore-head and crown, mantle, back and upper 

 tail-coverts being uniform black-brown, sides of head, back of neck, 

 scapulars and usually rump narrowly fringed dull white giving a 

 speckled appearance ; whole under-parts white with sides of head, 

 most of throat, upper-breast, sides and flanks much speckled brown- 

 black, centre of breast and belly sometimes speckled, sometimes 



