THE CHANGES OF PLUMAGE IN RED GROUSE 49 



soon becomes blackened and worn by the " burrens " 

 or charred stalks of old burned heather. 



(4) The perfect flight -feathers of the wings and tail. 



(5) The very large claws. 



In February the cock Grouse is still in the darker winter plum- February, 

 age. Young feathers of this "winter plumage " may still occasion- 

 ally be found on the hind-neck, nape, and head in backward birds. 



In March the cock Grouse normally shows no change ; but March, 

 towards the end of the month in exceptional instances individual 

 birds may be found with a few precocious feathers of the autumn 

 plumage making their appearance on the back of the head 

 and neck. These are very probably feathers irregularly 

 developed to take the place of those which have been lost 

 during encounters with other males. 



In April the cock Grouse still shows no change. In this April, 

 month there are often greatly increased opportunities for the 

 addition of skins to a collection, because it happens to be a 

 month of very high mortality from " disease." The birds are 

 found not only by the keepers who are out early in the month 

 in search of fox-earths, and who are generally also burning 

 heather about this time, but also later by the shepherds when 

 ranging the moor in the lambing season. Thus a very large 

 proportion of males are badly diseased, and comparatively few 

 birds are in perfect health. It follows that in the series of 

 skins of cock birds representing the month of April, the great 

 majority are very backward. Healthy birds have still the 

 old, rich, red, copper - coloured throat of the winter plumage 

 and fresh - looking " autumn " feathers round the neck, 

 upper back, and mantle, while the winter and old autumn 

 plumage of the rump and back is bleached and faded. The 

 backward birds are easily picked out, as they have not yet 

 assumed their " winter " plumage, and are still mostly clad in 

 old, worn autumn plumage of the previous year. If an April 

 bird has newly and thickly feathered legs and feet, it means, 

 almost certainly, that the " winter " plumage has been put on 

 very late. The healthy Grouse should now be moulting the 



