MEW GULL— BLACK SKIMMER 117 



streaked with grey. The young birds are mottled 

 with brown. See Plate 38, Fig. 223. 



The Herring Gull is common in both Europe and 

 America and the two forms are practically alike in 

 size and colour. This is the bird so commonly seen in 

 our harbours and following in the track of vessels. 



Nearly allied to the Herring Gull is the Great 

 Black-backed Gull, a rather larger bird than the for- 

 mer and distinguished from it by having a dark, slaty 

 black instead of pale grey back. The tips of the 

 wings and rest of the plumage are pure white. It is a 

 more northern species than the Herring Gull, but is 

 frequently seen in company with them. 



The Common European Gull, or Mew Gull, as it 

 is called in Great Britain, and the Kittiwake, have no 

 decided difference of plumage, except that in winter 

 the head and upper part of the neck become flecked 

 with grey, as in the Herring Gull. In the Kittiwake 

 the hind-toe has become reduced to the vanishing 

 point., See Plate 38, Figs. 224, 225. 



There are several species of these birds in this coun- 

 try, but they differ little in general appearance. 



The Black-headed Gull differs from those just de- 

 scribed in that during the summer months the head 

 assumes a dark brown colour, which, when the bird is^ 

 flying, looks black; hence its name. Young birds in 

 their first plumage may be readily distinguished by 

 the fact that the small feathers of the wings are brown, 

 while the tail has a black bar across the tip. But the 

 fully adult characters are assumed on the comple- 

 tion of the first year — in which it differs from the 



