332 BRITISH BIRDS. 



some irregularly disposed tufts of seaweed. It was the I3tli of July, and 

 unfortunately the eggs had all hatched ; but we shot four old birds, and 

 secured half a dozen young in down, which were running about on the 

 sand. The parents were very bold, and made repeated downward swoops 

 upon us ; the rest of the (lock kept well out of range, soon settling down 

 on a point at the extreme end of the island, and on being fired at there, 

 flew right away. 



At its other breeding-places, the Glaucous Gull, like the Ivory Gull 

 and the Iceland Gull, sometimes makes its nest on the sand like a Tern, 

 and sometimes on ledges of the cliffs like a Kittiwake. The nest is a 

 very careless structure, generally composed of dead grass and seaweed, 

 and three appears to be the full complement of eggs, which are usually 

 laid during the first half of June. They vary in ground-colour from pale 

 brown to pale olive-brown and pale bluish green. The surface-spots are 

 dark brown, occasionally approaching black, and the underlying spots are 

 brownish grey. The spots vary in many eggs from the size of a pea 

 downwards, and are nearly evenly distributed over the surface ; but occa- 

 sionally they are large bold blotches, principally collected round the large 

 end of the egg, and often confluent. A very handsome variety, presumed 

 to be of this species, is obtained at Vardo. The ground-colour is pale brick- 

 red ; the overlying spots are dark brick-red, and the underlying spots are 

 violet-grey. Occasionally the spots are well-defined, but generally they are 

 obscure and distributed over the surface. The eggs vary in length from 3-3 to 

 2-8 inch, and in breadth from 2"lto 1*9 inch. Eggs of the Glaucous Gull are 

 indistinguishable from those of the Great Black -backed Gull, and small ex- 

 amples resemble large eggs of the Herring- and Lesser Black-backed Gulls. 



The Glaucous Gull is almost as large as the Great Black -backed Gull. 

 Adults in breeding-plumage have the mantle, scapulars, and wing-coverts 

 a delicate French grey ; the rest of the plumage is pure white. Bill 

 yellow, with an orange-red spot on the angle of the lower mandible ; legs 

 and feet flesh-colour ; orbits vermilion in fully adult birds, but pale flesh- 

 colour during immaturity; irides very pale straw -yellow. After the 

 autumn moult the head and neck are streaked with grey. It is not 

 known how old the Glaucous Gull is when its adult plumage is assumed ; 

 but in the spring preceding the final autumnal moult into adult winter 

 dress, a mottled plumage is acquired, of so pale a character that it fades 

 during the summer into a creamy white, and in rare instances into pure 

 white. The intermediate plumages are white, mottled with brown, the 

 darkest being that of young in first plumage, which closely resembles that of 

 the Herring-Gull, but is still paler, especially on the primaries. Young in 

 down are grey, sparingly and obscurely mottled with black on the back. 



