556 THE BIRDS OF HELIGOLAND 



the larger species, are met with here all the winter months during 

 violent westerly and north-westerly gales, when they seek a tem- 

 porary shelter on the lee side of the island. While roving over 

 the sea in all directions in search of food, they execute many rapid 

 beats with their wings, continuously displaying at the same time 

 the peculiar greyish-black (grauschwarz) colour of their under- 

 sides. 



Soon after New Year the light bluish-grey (bldulicligrau) 

 feathers of the occiput already begin to undergo the alteration to 

 the black colour of the breeding plumage. This black colour first 

 makes its appearance on the shaft of each feather, and then spreads 

 in the form of a fine black dust over the remainder of its surface. 

 In the feathers of the underside of the head, the foreneck and sides 

 of the neck, which in the winter are pure white, the alteration of 

 colour commences at the extreme tips of the barbs of each feather, 

 the deep pure black colour appearing there in the form of fine 

 specks, which at first form a fine black edge around the tip of the 

 feather ; this gradually advances towards the root of the feather, 

 and finally overspreads its whole surface. This alteration of colour 

 from perfectly pure white to deepest black commences simultane- 

 ously at the lower border of what is subsequently the black marking, 

 and gradually extends upwards, so that in the end the part knoAvn 

 as the chin is the only spot where the white colour is still apparent. 



I have only obtained this gull here twice in pure summer 

 plumage : one of these examples, perfect in all the feathers of its 

 plumage, was, strange to say, shot on the 15th of November 1861, 

 although the black markings of the head evidently do not date from 

 the previous spring, but are quite fresh, close, and new, like all the 

 rest of the plumage. I have repeatedly noticed similar appearances 

 in Red-throated Divers (Colymbus septentrionalis), but never in the 

 case of any other bird. 



The nesting range of the Little Gull extends from Lakes Ladoga 

 and Onega, through southern Siberia, to the Sea of Ochotsk. 



360. Sabine's Gull [SABINE'S MOWE]. 

 LARUS SABINII, J. Sabine. 1 



Larus Sabinii. Naumann, xiii. ; Blasius, Nachtrage, 272. 



Sabine's Gull. Dresser, viii. 337. 



Mouette de Sabine. Temminck, Manuel, iv. 488. 



This beautiful little Gull is at once distinguished from its con- 

 geners by its distinctly forked tail. I have obtained the bird on two 



1 Xema sabinii (J. Sabine). 



