274 ALLEN'S NATURALIST'S LIBRARY. 



ed. Yarrell's Brit. B. iii. p. 60 (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 tetrix^ Grant, Cat. B. Brit. Mus. xxii. p. 53 (1893). 

 id. in Allen's Nat. Libr. ix. p. 45 (1895). 



Adult Male. Plumage mostly black ; the under tail-coverts 

 pure white. Total length, 23-5 inches; wing, 10-3; tail, 8'8 ; 

 tarsus, 1*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. mlokosiewiczi, and the tail shorter. Total 

 length, 17 inches; wing, 8-9; tail, 4-5; tarsus, r6. 



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 (I.e.). 



