PLUMAGE CHANGES OF THE COCK GROUSE 35 



claws are often in this month very long and strong. Occasionally a pale 

 bleached feather of the preceding "autumn plumage" is to be found on the 

 flanks, middle of the breast or neck, and may be recognised by its frayed 

 edges ; and occasionally (e.g., No. 539), in a very backward bird, there may 

 be many such worn and faded feathers on the chest and flanks, but such 

 u case is invariably the result of sickness. On the dorsal side there is again, 

 broadly speaking, a general uniformity of chestnut, bright or dark, or of 

 blackish feathers, with fine black transverse markings ; but in almost every 

 bird there may be found a considerable number of the old black - centred 

 " autumn plumage " feathers remaining, with their frayed and faded edges 

 of whitish-buff (PI. v.). On the lower back and rump the more worn 

 and faded feathers predominate. The primary and secondary quills are all 

 complete, and are but a few months old, having been renewed between 

 June and August ; and the same may be said of the rectrices. 



The following points in the cock Grouse of January are characteristic. 



(1.) The rich copper-red, generally unbarred feathers of the throat and 

 fore-neck (PI. xvi., Figs. 3 and 4). 



(2.) The fine barring of the chestnut, dark rufous -chestnut, or blackish- 

 brown of the back, with the scattered black-centred feathers of the 

 last " autumn plumage." 



(3.) The thick, white feathering of the feet and legs, which soon becomes 

 blackened and worn by the "burrens" or "colons," the 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 plumage. 

 Young, sheathed and growing broad - barred feathers, the remains of 



February. 



the " winter plumage," may still occasionally be- found on the hind- 

 neck, nape, and head in backward birds. 



In March the cock Grouse normally shows no change ; but 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 month there are 



