70 BRITISH BIRDS. [vol. vii. 



in his statements about the age when the male gets its 

 full plumage. After Briinnich, Holboll {Ornith. Beitrag 

 zur Fauna Gronlands, pp. 69-73) seems to have been 

 the next author who diagnosed the plumage-change 

 of the Eider correctly. On page 72 he says that, 

 having compared a great number of young birds of 

 both species {8. mollissima and >S'. spectahilis), lie has 

 come to the conclusion that both require two years 

 to become full grown, so that young birds which were 

 hatched in 1840 were full grown in the autumn of 1842 

 and had attained a complete winter-plumage in October.* 

 This period, he states, is ahke for both sexes. During 

 the first year the female bird is quite grey, without the 

 white bands on the wings ; in the second year she attains 

 almost the same colour as the old birds, only differing 

 from these by the absence of the white bands on the 

 wings. Professor CoUett gives {Mindre Meddelelser ved. 

 Norges Fuglefauna, 1881-1892, pp. 284-286) a detailed 

 account of the plumage-change which seems to leave the 

 reader in a state of some doubt, for he believes that the 

 young males do not begin to turn white until the second 

 winter. Most English authors, except Booth, say 

 very little about the plumages of the Eider, and what 

 they do is strictly of a non-committal order. By far 

 the best account of the sequence of plumages of 

 S. mollissima and its allied races is to be found in Mr. 

 E. Lehn Schioler's paper on the Eider Duck [Somateria 

 mollissima L.) and some of its alHed races, which was 

 published in the Dansk ornithologisk Forenings Tidsskrift 

 (Vol. III., June, 1908, pp. 109-149). This contains a 

 very complete summary of Mr. Schioler's views on the 

 plumage passage of the Eider, as well as notes on skeletons, 

 breeding-habits, and the distribution of allied races. 



In the following descriptions of the plumages of the 

 Common Eider, I have taken specimens whose plumage 

 is normal at the days mentioned. Sometimes there is a 



* Broadly speaking this is quite correct, although many males do 

 riot attain full plumage until December, owing to the delay in moulting. 



