348 BRITISH BIRDS. 



no occasion to modify or alter the conclusions then arrived at, 

 which were based on incontestible evidence. The majority 

 of the birds I had for examination are preserved in the 

 Natural History Museum, and may be examined by any one 

 who is interested in the matter. 



When I first began to make a serious study of the apparently 

 endless variation to be found in the plumage of this species 

 there was no material available for examination in the 

 Museum ; but through the kindness of various landowners 

 in Scotland I was able to procure a large and very complete 

 series of birds killed twice a month during every month of 

 the year, and was thus able to examine in the flesh the plumage 

 of every individual. It was then that I discovered the 

 remarkable peculiarity of the moults of the Red Grouse, 

 one without parallel among birds, even of this genus, viz., 

 that the changes of plumage of the male and female occur 

 at different seasons. 



The facts ascertained may be briefly summed up as 

 follows : — 



The male has no distinct spring-plumage, but has distinct 

 autumn- and winter-plumages, and retains the latter through- 

 out the breeding season. 



The female has a distinct spring-plumage, which is complete 

 by the end of April or the beginning of May, also a distinct 

 autumn-plumage, which is retained till the following spring. 



To put it more concisely, both male and female have two 

 distinct moults during the year, but in the male they occur 

 in autumn and winter, and in the female in spring and autumn, 

 the former having no distinct spring- and the latter no 

 distinct winter-plumage. 



The Red Grouse is generally regarded as merely an insular 

 form of the Willow-Grouse, and it might naturally be supposed 

 that as the British species does not turn white in winter, 

 such protective plumage being unnecessary in the localities 

 it inhabits, the winter-moult had been gradually dropped. 

 But, as has been already shown, this is the case with the 

 female only, and the male, for some unknown reason, changes 

 all or the greater part of the newly-acquired buff-and-black 

 autumn-plumage for a winter-garb of chestnut and black, 

 which is retained till the following autumn. 



During the past five years Dr. Edward A. Wilson, while 

 acting for -the "Grouse Commission," has examined many 

 thousands of Red Grouse killed throughout the year, and he 

 confirms my observations and agrees that without doubt the 

 male breeds in his winter-plumage. 



