Changes of Plumage in Grouse 291 



snow melts and the general aspect of the country is dark, 

 so that a white object would be easily perceived. In 

 autumn when the aspect of the country is greyer, and the 

 green of summer disappears, while the mosses of the grey 

 mountains become conspicuous, there also would the 

 Ptarmigan or the " Ryper " be seen at once, if the dark 

 plumage of summer were retained, or the white plumage of 

 winter were donned before the snow began to fall. Thus 

 the grey autumn plumage of these Grouse corresponds to 

 the aspect of the country, just as the liveries of spring and 

 winter also assimilate to the surroundings of the birds at 

 those seasons of the year. 



The changes of plumage undergone by our Red Grouse 

 [Lagopus scoticus), which is an insular form of the Willow 

 Grouse, do not correspond with those undergone by the 

 latter species, but the Ptarmigan, which inhabits higher 

 grounds, changes on the mountains of Scotland exactly in 

 the same way as it does in Norway. Accustomed in the 

 course of ages to a milder climate than that in which the 

 Ryper has to exist, our Red Grouse has lost the necessity 

 for turning white in winter, and the female has no distinct 

 winter dress, though she moults in summer and again in 

 autumn. The male, however, moults in autumn and 

 winter, and retains the latter plumage until the following 

 autumn, his winter dress thus remaining throughout the 

 breeding season. Mr. Ogilvie Grant, to whose careful 

 studies of the species the above-mentioned curious facts of 

 the seasonal liveries of the Red Grouse have been due, 

 sa)'s that " the great peculiarity in the species, and one 

 without parallel even in the group of Willow Grouse, lies 

 in the fact that the changes of plumage in the male and 

 female occur at different seasons. The male has no distinct 

 summer plumage, but has distinct autumn and winter 

 plumages, and retains the latter throughout the breeding- 

 season. The female has a distinct summer plumage, 



