160 BRITISH BIRDS' NESTS. 



whilst nesting in June on a northern moorland 

 tarn. The Black-headed Gull is subject to con- 

 siderable variation in plumage, not only in regard 

 to season but age. 



Situation and Locality. On the ground, in a 

 tussock of coarse grass, tuft of rushes, or a slight 

 hollow on the bare ground ; in swamps and bogs, 

 at the edges of and on islands in tarns and lakes. 

 In large colonies at a great number of suitable 

 places throughout the British Isles. Three famous 

 places in England are Scoulton Mere in Norfolk, 

 where the bird has nested in thousands for upwards 

 of three hundred years in succession, at Pallinsburn 

 in Northumberland, and at Ravenglass in Cumber- 

 land. Although gregarious, I have frequently met 

 with solitary pairs nesting on small mountain tarns. 

 Materials. Sedges, rushes, tops of reeds, and 

 withered grass ; generally in small quantities, some- 

 times quite absent, and at others in fairly large 

 quantities, much depending upon the site chosen. 

 Eggs. Two or three ; usually the second num- 

 ber, and occasionally four, varying from pale olive- 

 green to light umber -brown in ground-colour, 

 blotched, spotted, and streaked with blackish- 

 brown and dark grey. Size about 2.2 by 1.45 in. 

 They are subject to great variation in regard to 

 size, shape, and colour ; but their small size 

 and the presence of the parent birds easily dis- 

 tinguish them. (See Plate X.) 



Time. April, May, and sometimes as late as 

 June. 



Remarks. Resident, but subject to much local 

 movement. Note : a hoarse cackle, resembling a 

 laugh when quickly repeated. Local and other 

 names : Red-legged Gull, Laughing Gull, Peewit 



