2l8 THE BIRDS OF THE BRITISH ISLES. 



though often smaller, closely resemble those of its constant 

 neighbour ; I have found the eggs in a scratched hollow without 

 a vestige of nesting material. The eggs (Plate 94), two or three 

 in number, are sometimes greenish, but usually stone-coloured 

 or buff in ground, and boldly spotted ; they are laid in May. 

 I doubt if there is any certain distinction between the mottled 

 nestlings (Plate 99) and those of the Herring-Gull ; the down, 

 often greyish, is sometimes warm in tint, but varies greatly. 

 The blackish bill is at first pale at the tip, but soon darkens ; 

 the legs are dull slate but become browner, and the irides, dark 

 brown at first, grow paler and more yellow during the three or 

 four years of immaturity. In the first brown dress the two can 

 only be distinguished by close examination, but after a moult 

 or two the darker mantle becomes evident. The bill grows 

 yellower, the black remaining on the angle until replaced by 

 red when almost mature plumage is attained, and the banded 

 tail becomes mottled before it is finally pure. 



The adult bird, slate-grey and white, has " mirrors " on the 

 first two primaries ; the bill is yellow with red on the angle, 

 the legs and irides are yellow, and the orbital ring vermilion. 

 In winter the head and neck are streaked with grey. Length, 

 22 ins. Wing, 16 ins. Tarsus, 2*6 ins. 



Glaucous Gull. Lams giaucus Briinnich. 



The pale plumage of the Glaucous Gull (Plate 96) is sug- 

 gestive of an Arctic species, for not only does this gull nest 

 north of the Arctic Circle in both hemispheres, but it often 

 remains for the winter. It is, however, also a migrant, and 

 wanders south as far as the Mediterranean, and, in America, 

 Florida ; to the Orkneys, Shetlands, and Outer Hebrides it is 

 a regular autumn visitor. Both mature and immature birds 

 reach the Shetlands in October, and some, mostly young, remain 

 all winter. On the east coast it is a frequent "hard-weather" 



