2 74 ALLEN’S naturalist’s LILRARY. 
ed. Yarrcll’s Brit. B. iii. p. 6o (1883); Seebohm, Hist. 
Brit. B. ii. p. 435 (1884); Lilford, Col. Fig. Brit. B. part 
vii. (1888) ; Saunders, Man. Brit. B. p. 479 (1889). 
Lyrurus Grant, Cat. B. Brit. Mus. xxii. p. 
id. in Allen’s Nat. Libr. ix. p. 45 (1895). 
Adult Male.— Plumage mostly black ; the under tail-coverls 
pure white. Total length, 23-5 inches; wing, 10-3; tail, 8-8; 
tarsus, I '9. 
Adult Female.— Plumage mostly rufous and buff, barred with 
black, the black bars on the breast being much coarser than 
in the female of L. mlokosimncsi, and the tail shorter. Total 
length, 17 inches; wing, 8-9; tail, 4-5; tarsus, i-6. 
Nestling. — Covered with yellowish down, patterned with 
chestnut-brown on the upper parts. 
Changes of Plumage.* — During the heavy autumn moult, 
which takes place in July and August, when the males are 
entirely devoid of tails and generally incapable of flying more 
than a few yards at most, a temporary protective plumage, like 
that of the female, clothes the head and neck, and the throat 
becomes more or less white. The object of this change is 
obvious, for the black head and neck of the male are con- 
spicuous objects among the heather and rushes, but the 
rufous-buff feathers, with their black bars and marks, harmonise 
perfectly with these surroundings and enable the defenceless 
birds to escape the observation of their enemies. The barred 
feathers of the head and neck are not cast and replaced by 
black till the rest of the plumage has been renewed, and the 
bird is once more able to fly. 
The young male, unlike that of the Caucasian Black Grouse, 
attains the black adult plumage at the first autumn moult, and 
by November resembles the old male, but some of the finely 
mottled shoulder-feathers and inner flight-feathers of the first 
plumage are generally retained till the second season, and the 
outer tail-feathers are shorter and less beautifully curved. 
Females that have become barren from age or accident 
commonly assume the male plumage to a greater or less ex- 
* The descriptions of the plumage are copied from Mr. Ogilvie Grant’s 
volume {/.(•.). 
