40 The Natural History of British Game Birds 
are generally bare, and it only keeps such feathers as have come into the plumage since 
March. In this sombre dress of buff and black and faded summer feathers nearly all 
males of the several forms are alike, and it would seem that this dull plumage is somewhat 
similar to the eclipse plumage of the ducks. In reality it might be named the " eclipse " 
dress of the cock Grouse ; for with autumn — that is to say, early September — commences 
the big change to winter, when all feathers, except the primaries, secondaries, and tail, are 
again renewed. This, however, we need not discuss, as I have already explained it 
at length. 
In conclusion, it is the case that the summer or breeding plumage of the cock Grouse 
is achieved, for the most part, by repigmentation and pattern change of most of the winter 
feathers below the neck, and above that part by a gradual spring moult (differing consider- 
ably in individuals as to date), whilst in the case of certain males these ornamental feathers 
may extend in small numbers to the nape, scapulars, chest, back, and tail-coverts, thus 
partly forming an ornamental nuptial dress similar in character to that of the Willow 
Grouse. It is also a new and curious fact that the male should moult the feathers of 
the legs and feet at any period between March 30th and June 17th, as the margin of 
time is so very wide. 
The following list of birds gives details of the plumage of the most interesting 
specimens. The numbers indicate conspicuous changes : — ■ 
Male Grouse sent for Examination during the Year 1909 
1. March 16th. — Bearnock, Inverness-shire (H. F. Wallace). Richly coloured bird 
in fine plumage with good gloss ; the reds and blacks are more brilliant than during 
winter ; comb well developed ; feet and legs as in winter ; no new feathers. 
2. March 2/^th. — Cambusmore, Sutherland (Mrs. Wilfred Loder). A large number 
of new rich black and golden yellow feathers coming in all over crown, cheeks, throat, 
and back of the neck, but the rest of the plumage winter feathers well repigmented with 
fine gloss ; rump almost blood-red, with some feathers not recoloured and dull ; legs and 
feet as in winter. A very fat bird in high condition. 
3. March 30th. — Bleaton Hallet, Blairgowrie, Perthshire (J. M. K. Marshall). 
Repigmentation very rich, together with considerable pattern change on the whole plumage 
except crown, cheeks, throat, and neck, which are being renewed with brilliant breeding 
dress feathers. The feathers of the legs and feet have fallen and are nearly bare. 
(The legs and toes of another example from Pitlochry, sent on April 1st, were also in 
full moult.) 
From this date until May 1st all birds were acquiring or had gained similar plumage, 
some moulting feet and toes, and others not doing so. 
4. May \st. — Buxton, Derbyshire (His Grace the Duke of Devonshire). New head 
and neck feathers complete, but in addition many new rich golden and black feathers 
coming into nape, back, scapulars, and breast, but none on tail-coverts, wings, or belly. 
Old winter feathers mostly repigmented and possibly repatterned ; legs and toes bare. 
(A bird from Broomhead Moor, already referred to, was even more advanced, having 
feathers in tail-coverts as well.) 
