166 BRITISH BIRDS' NESTS. 



Materials. Seaweed, heather, wool, and dry 

 grass in variable quantities. Sometimes they are 

 very abundant and at others almost entirely 

 absent. 



Eggs. Two or three, generally the latter number. 

 Yellowish-brown or stone -colour to light olive- 

 brown, blotched with slate-grey and dark brown. 

 The spots are not very large, and generally dis- 

 tributed over the surface of the egg. Size about 

 3.1 by 2.1 in. The large size of the eggs and the 

 small spots are distinguishing characteristics. (See 

 Plate X.) 



Time. May and June. 



Remarks. Resident, but wandering during the 

 non-breeding months. Note : a harsh croak or 

 laugh. Local and other names : Cob, Blackback, 

 Great Black Salmon Gull and White Gull. Gre- 

 garious in some parts and solitary in others. Not 

 a close sitter, but demonstrative when intruded 

 upon. The bird figured in our tailpiece in the act 

 of alighting was exceedingly shy and suspicious, 

 although she could see nothing but the lens of the 

 camera at a considerable distance from her. 



GREAT BLACK-BACKED GULL ALIGHTING. 



