64 The Natural History of British Game Birds 
round the neck is often russet brown broadly crossed with black bars. In September 
these parts change to grey. In fact, both in the case of the male and the female, the 
whole plumage is undergoing a colour change as well as a moult throughout August, 
September, October, and November ; the birds apparently having the power to assimilate 
their plumage to the local environment to a wonderful degree. In mild winters, when 
there is little snow, we see both males and females retain many of the grey autumn 
feathers on the back, scapulars, neck, head, and rump, whilst in seasons of much snow 
the birds will, in December, lose these and become quite white. 
Adult Female. — The female acquires her autumn and winter dress more slowly 
than the male. In August it is common to see examples with the head unchanged and 
many of the old summer feathers still retained till the end of the month on the neck, 
head, and scapulars. When the new winter feathers come in at the end of October 
many of these are seen to be not white, but partly coloured grey and white. These 
new feathers are not again renewed as some naturalists would have us believe, but 
change the grey colour to pure white, either suddenly or gradually, according to 
weather conditions. The general colour and markings of the female in August and 
September are a lighter tint of grey than the male, and the black vermiculations finer. 
Male. — Length, 14.5 in. ; wing, 7.6 in. ; tail, 4.6 in. ; tarsus, 1.3 in. 
Female. — Length, 14 in.; wing, 7.4 in.; tail, 4.1 in.; tarsus, 1.3 in. 
The plumage of the Ptarmigan is difficult to understand, because it is seldom 
stationary for any length of time, except in summer. A brief summary of these 
changes will give the reader some idea of their monthly alterations. 
January. — Males and females in the white plumage, sometimes with a few grey 
feathers on back, neck, flanks, or scapulars. 
February. — At the end of this month, if the winter is mild, a few of the first 
summer plumage begin to show, always on the neck. 
March. — Summer plumage coming in gradually ; birds in full moult, except primaries, 
secondaries, and tail, the breast and tail covert feathers not being complete. 
April. — Summer plumage complete with a few winter feathers still on the tail- 
coverts (a single feather is sometimes retained until July). 
June.— Summer plumage. 
July. — A gradual darkening of the whole plumage due to tip-covering. I have seen 
Scotch males as black on the chest as Icelandic or Norwegian examples ; commence- 
ment of the autumn moult. 
August. — A very general moult to autumn plumage. 
September. — Continuous moult ; the head and neck of males turn from brown to 
grey. Tail and wings now renewed ; females may still retain a few summer plumage 
feathers. 
October. — Continuous moult of winter plumage now mixing with grey autumn 
plumage ; the autumn feathers changing colour in sympathy with incoming white 
plumage, and the new winter dress exhibiting many partially grey and white feathers 
(in sympathy with autumn dress), which will in turn change to pure white. Leg and 
feet feathers now complete. 
November. — A few of the autumn feathers remain in head, neck, scapulars, flanks, 
