132 THE BIRDS OF THE BRITISH ISLES. 



comrades. At rest the bird stands on one leg, its head sunk 

 in its shoulders or with its bill in the scapulars ; if approached 

 it will, without putting down the raised leg, hop slowly away. 

 The rush of wings of one of the vast flocks when disturbed 

 is a sound to remember, the sight most impressive ; the rising 

 cohorts form a dense curtain. The aerial movements of the flock 

 are as complicated and well ordered as those of the Dunhn ; 

 turning and twisting the compact body skims out over the 

 water, rises or descends, or thins out into a long undulating 

 line ; often the whole body returns whence it rose. The Knot 

 is strong and swift on the wing, capable of sustained flight. 

 Many birds leave the west coast before the end of April, but 

 passage continues throughout May ; Mr. Holder saw over 500 

 on June 20th in full chestnut dress. In the last week in July 

 or early in August the young birds arrive from the north ; 

 Mr. Holder saw one flock 2000 strong on August ist, and notes 

 how from a distance these mobs of buff-breasted birds look 

 "as if suffused with rose." Within a few days some adult birds, 

 already in grey dress, may be noticed, and the passage continues 

 until October. All agree that the young come first, but most 

 writers say that the old birds are much later, yet Herr Manniche 

 saw no old birds in Greenland after August 8th. The chestnut 

 of the adult birds when gradually attaining winter grey is much 

 deeper than the buff of the young, but it may be that some 

 observers have thought that birds in partial winter dress were 

 juvenile. Even in the second week in September I have seen 

 birds showing much chestnut on the under parts amidst many 

 hundreds in complete grey plumage, but Mr. Holder rarely sees 

 full summer dress even in early August. 



The Knot occurs inland more frequently than is usually 

 supposed, and occasionally in autumn there is overland migra- 

 tion. Single birds, probably weaklings that have fallen out of 

 passing flocks, are met with on inland waters in winter as well 

 as in autumn. 



