Spring Plumage without a Moult. 453 



(Harelda glacialis) is a good example. This handsome and 

 sprightly Duck is a regular winter visitor to our northern 

 coasts, and frequently remains in the vicinity of the Orkney 

 and Shetland Islands till the breeding-dress is assumed. 

 During the winter the birds move about in flocks (from 20 

 to 100 in number), which in March become more scattered, 

 the birds then often being seen in pairs. Birds of this 

 species are, however, as I think, never paired until they 

 reach their breeding-ground near the Arctic Circle, for at 

 the beginning of April they hold regular courting-parties, as 

 other Ducks do. This is probably pseudo-erotic, as the 

 whole of the birds leave in big parties for the northern 

 regions about ten days later. In some seasons adverse 

 northern head- winds delay them, and their journey may be 

 deferred till the beginning of May. When this happens, 

 though the birds become extremely restless and shy, it is 

 possible to obtain specimens which show the complete 

 summer dress fully developed. In the spring of 1886 I was 

 fortunate enough to obtain a fine series of this Duck on 

 Loch Stennis and the adjoining bays of Pomona (Orkneys). 

 ■ By the examination of these freshly- killed specimens it was 

 plain that all the russet-and-black feathers of the head and 

 neck were new ones, and could be distinctly seen coming 

 from the new quills, whilst the old light feathers of the 

 winter plumage would come off in the hand on being stroked. 

 In one or two cases the long feathers of the wing-coverts 

 showed an old winter feather in process of change to sum- 

 mer colour. This, however, I regard as exceptional, for the 

 scapulars are also generally shed, whereas the feathers of the 

 wings, tail, and many of those of the breast and back are 

 not cast. 



It is hardly necessary to give any illustration of this, 

 which is the simplest of all changes of plumage, for, assuming 

 that the reader is familiar with the Loug-tailed Duck in its 

 summer and winter dress, he has only to imagine the winter 

 feathers being gradually cast (the last to change, curiously 

 enough, being the top of the head) and the summer ones 

 taking their place. 



