BLACK-GROUSE 
LYRURUS TETRIX 
(Plates II-IV) 
Tetrao tetrix, Linn, Syst. Nat. i, p. 274 (1766) ; Gould, Birds Europe, v, pi. 250 (1837) ; 
Saunders, ed. Yarrell, Brit. Birds, iii, p. 60 (1882) ; Seebohm, Hist. Brit. Birds, ii, p. 435 
(1884) ; Lilford, Col. Fig. Brit. Birds, pt. vii (1891) ; Millais, Game Birds, p. 21, pis. and 
woodcuts (1892) ; Saunders, III. Man. Brit. Birds, p. 493 (1899). 
Lyrurus tetrix, Swains, and Richards. Faun. Bor.-Amer. ii, p. 497 (1831) ; Ogilvie-Grant, 
Cat. Birds Brit. Mus. xxii, p. 53 (1893) ; id.. Handbook Game Birds, i, p. 45 (1895) ; Millais, 
Nat. Hist. Brit. Game Birds, p. 18, pis. (1909). 
TValsingham and Payne-Gallwey, “Badminton Library” Moor and Marsh, p. 45 (1886). 
DULT male. (September to July). — General colour black ; 
the feathers of the head, neck, lower back and rump 
/ widely margined with purplish steel-blue, those of the 
jf mantle more narrowly edged with the same colour. 
i The outer webs of the outer primary quills pale brown, 
JK more or less mottled with white, the basal part of the 
innermost primary and secondary quills white, the secondaries being also 
narrowly margined at the extremity with white. Except in the most adult 
examples, there are usually traces of rufous mottlings on the outer 
secondaries. Axillaries, under wing -coverts, and under tail -coverts pure 
white, though in some examples the latter have a black heart-shaped spot 
at the extremity. Thighs more or less mixed with white. Naked skin and 
wattle above the eye scarlet ; bill black ; feet horny brown. Total length 
23*5 inches ; wing 10*3 inches ; tail 8*8 inches; tarsus 1*9 inch. 
Adult male. — (July to September). — In summer, when the males are 
moulting, the black feathers on the back and sides of the head and nape, 
and often some of those of the upper mantle, are replaced by a temporary 
plumage of chestnut or brownish -buff and black barred feathers, some- 
what like those of the female. The chin and throat are more or less white. 
This “ eclipse ” plumage is retained until the quills of the wings and 
tail have been renewed; the new black feathers on the head and neck 
being the last to appear, and often incomplete until the latter half of 
September. 
Immature male in first autumn-plumage.— blue gloss on the plumage 
is much less brilliant, many of the feathers on the head and neck are 
narrowly fringed with rufous, and the wing -coverts, scapulars and 
secondary quills are more or less densely vermiculated with the same 
colour. The first primary quill is more pointed than in the adult, and the 
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