THE BRITISH BLACK GROUSE. 857 



plumage occur as do hybrids with Capercaillie, Pheasant and Red 

 Grouse. 



Nestling. — Much like that of Capercaillie but top and back of 

 crown with a " cap " of chestnut surrounded with black line and 

 sometimes slightly mottled black ; black marks on sides of head, 

 lores and fore-part of crown much as in Capercaillie ; down centre 

 of back of neck a black line ; rest of upper -parts slightly darker than 

 Capercaillie ; base of throat only slightly tinged orange ; toes bare. 



Juvenile. Male. — Whole upper-parts barred black and buff, 

 black barring varying in width but broader on mantle and back 

 and buff darker and more rufous and somewhat vermiculated black ; 

 sides of head and sides of neck paler, often whitish and more 

 spotted brown-black ; chin and throat same but with fewer black 

 spots and base of throat with squamated appearance and more 

 rufous ; rest of under-parts buff (on breast rufous -buff) fairly 

 closely barred black-brown, dark on breast, paler on belly ; under 

 tail-coverts uniform pale buff ; tail-feathers narrow and short, 

 rufous-buff barred and freckled black-brown and narrowly tipped 

 buff ; primaries much like adult female but more mottled buff at 

 tips ; secondaries brown barred and mottled buff chiefly on outer 

 webs and with small wedge-shaped buff tips, innermost more rufous 

 and vermiculated and with broad black bars at tip ; wing-coverts 

 and scapulars rufous -buff broadly barred black and with buff to 

 whitish shaft-streaks broadening at tips. Female. — As male but not 

 so rufous on upper-parts and w r ing-coverts, breast less rufous and 

 more widely barred. 



First winter. Male. — Like adult but glossy blue not so uniform, 

 varying but always more and coarser rufous vermiculations on 

 scapulars, inner wing-coverts and outer webs of secondaries ; 

 mantle sometimes and upper tail-coverts often more or less ver- 

 miculated ; crown and especially neck usually with dark rufous 

 bars ; central tail-feathers narrowly tipped whitish ; some feathers 

 on chin and throat sometimes narrowly tipped white ; occasionally 

 some white shaft-streaks or narrow tips or rufous bars on breast ; 

 outer webs of primaries mottled, tips of two outer primaries 

 minutely freckled buff to rufous-buff. N.B. — Amount of ver- 

 miculation and barring varies greatly individually as does amount 

 of curling of outer tail-feathers. The juvenile plumage is com- 

 pletely moulted commencing when bird is about half grown and 

 while juvenile feathers are still growing on head and neck, but two 

 outer primaries which are among last juvenile feathers to grow and 

 are much like adult in structure and size are not shed. Moult often 

 continued to Nov. and sometimes Dec. First summer. — Moult on 

 head, neck and throat exactly as in adult. Female. — Like adult 

 and no certain distinction though outer two primaries usually more 

 sharply pointed and more vermiculated at tips. 



Measurements and structure. — $ wing 252 (one 246)-265 mm. 

 (1st winter 245-265), tail : central 75-100, outer 65-100 longer, 

 curled (1st winter 45-75 longer), tarsus 49-55, bill from nasal 



