DUCKS, GEESE, AND SWANS. 237 



Swan, two other species are British, in the sense of 



visiting our area to winter. 



HOOPER SWAN. 



This fine bird, the Cygnus musicus of Bechstein, 

 as well as of most modern ornithologists, is a 

 tolerably common winter visitor to the British 

 Islands, frequenting inland waters as well as the 

 coasts. It is of more frequent occurrence in 

 Scotland, than in England or Ireland. The 

 Hooper sometimes rendered Whooper or Whist- 

 ling Swan, both names being derived from the 

 bird's notes, may be distinguished from its two 

 British allies by having the basal portion of the bill 

 extending below the nostrils, yellow. Like many 

 other species that visit us during winter from the 

 high north, its numbers vary a good deal in 

 different years, according to the mildness or severity 

 of the winter in regions lying directly north or 

 north-east of our area. In periods of long con- 

 tinued frost, great numbers of this Swan collect off 

 certain parts of our coasts, driven seawards from 

 inland waters. This Swan is rarely seen in British 

 waters before October or November, whilst in some 

 years it does not make its appearance in certain 

 localities before mid-winter. Its spring migration 

 northwards lasts through April and May. Whilst 

 on passage the flocks of this species form into some 

 rectilinear figure and fly at vast heights. Gatke 

 remarks, that at Heligoland this Swan is seen most 



