GREATER WHITE-WINGED GULL 147 



former species. On the Fame Islands these gulls sometimes nest 

 in association with lesser black-backs. i\lthough in some cases slight, 

 the nest ma\- consist of a large loosely knit mass of grass and sea- 

 weed. The eggs, usually three, but sometimes two in number, are not 

 unlike those of the common gull in colouring, but are subject to much 

 greater variation, and thus resemble those of the lesser black-back, 

 from which they may be distinguished by their superior size, the length 

 ranging between 2^ and 3 inches. 



On South Saltee, in Ireland, is a well-known colony of herring- 

 gulls and lesser black-backs, which extends straight across a hill of a 

 couple of hundred feet in height from one side of the island to the 

 other. The nests occur in greatest number on the slopes, where they 

 occupy all available nooks and crannies, but some occur on the bare 

 hill-top, and one has been observed in a footpath. The herring-gulls 

 occupy more prominent and exposed situations than those selected by 

 the lesser black-backs ; while on the extreme rocky summits are a 

 few nests of the greater black-backed species. Thrift is used in the 

 construction of the nest. 



Greater white- 



wing-ed Gull (Larus 



hyperboreus). 



This species is generally 

 referred to in ornitho- 

 logical works as the 

 glaucous gull, from a 

 translation of its alter- 

 native scientific title, 

 Larus glmicus. Such a 

 title is, however, neither 

 descriptive nor good 

 popular English, and a 

 better name is that of 

 crreater white - win<Ted 



j^lv-clLV,! VVlllLV- >V11I,^\-VJ MOUNTED IN THE ROWLAND WARD STUDIOS 



gull, since the white greater white-winged gull. 



head and tail and white 



quill-feathers, together with its large bodily size and the absence of 

 black on the back, form the most distinctive characteristic of this 

 fine species. The white-winged gull is a circumpolar species, breed- 

 ing in the Arctic zones of both hemispheres, wandering southwards 



