THE CHANGES OF PLUMAGE IN RED GROUSE 75 



until the bird has been cut open and the internal anatomy exa- 

 mined. In these doubtful cases the only way to settle the point 

 is to cut the bird open down the middle of the abdomen, carefully 

 turn over the whole of the intestines from the right to the left 

 that is, from the bird's left side to the bird's right side without 

 tearing the attachments, and then, having exposed to view the 

 flattened reddish kidneys which lie closely packed into the 

 inequalities of the backbone and pelvis, to see whether an ovary 

 or a testis is revealed overlying the uppermost portion of them. 



It may be said that there is no other infallible means of 

 arriving at the sex of a Grouse at certain times of the year, 

 for it has so often happened that experienced and careful game- 

 keepers, who have handled Grouse for a lifetime, have certi- 

 fied a specimen as a cock, when the specimen has turned out to 

 be a hen, and vice versa. The mistake is unavoidable and 

 excusable, for in certain individual Grouse in the autumn- 

 winter plumage there is no reliable characteristic in the feather- 

 ing or in the supraorbital comb, or in any external part of the 

 bird, by which the sex can be distinguished. In most Red 

 Grouse, however, the confusion of sex is not possible, for it is 

 a matter of common knowledge that for a great part of the 

 year the cock and the hen are so wholly unlike one another 

 as to make it difficult for any one who did not know the birds 

 to believe them to be of the same species. Even in the summer 

 months, when the cock puts on a plumage closely simulating 

 the breeding plumage of the hen, there is a difference in the 

 general tone and colour. It is only in the autumn and winter 

 that it is possible to mistake the sex of individual birds. 



Generally speaking, the feathers of the head and neck give 

 the best indication as to sex in the autumn-winter plumage. 

 In the male the red colouring is, as a rule, far more uniform 

 than in the female. In the male also there is, as a rule, an 

 absence of black markings on these red feathers, except on the 

 upper part of the head, on the crown, and nape of the neck. 

 The cheeks are generally a clean bronze or chestnut-red colour ; 

 so are the feathers of the chin, throat, fore-neck, and upper 



