THE BIRDS OF HELIGOLAND 545 



can hardly reckon on obtaining even one specimen during the autumn 

 and winter months of each year, such inchvichials being invariably 

 young autunm birds, whoso phimage, in all cases brought under my 

 observation, is considerably lighter than that of the dull, brown- 

 coloured, similarly aged individuals of the larger species. Very strik- 

 ing differences of size arc displayed by these young birds inter- se. I 

 have often obtained specimens which, but for their relatively much 

 longer wings, might easily have been placed under the preceding 

 species. In the present species the wings project from seven to eight 

 centimetres beyond the tail, whereas in L. glaucus they are of the 

 same length as the tail. A birdstufter here, many years ago, 

 possessed a very light-coloured young bird of this species which 

 was actually but little larger than Larus canus ; I could not, how- 

 ever, induce him to part with the bird. 



The Iceland Uull breeds from Alaska and the Aleutian Islands, 

 throughout the coast-regions of Arctic North America as far as 

 Greenland. 



350. — Great Black-backed Gull [Mantelmowe]. 



LARUS MARINUS, Linn. 



Heligolandish : Old birds : Mante\ira,geT = Mantle-wearers. 



Young birds : Groot grii Kuhh = Great grey Gull. 



Larm marinvs. Naumann, x. 438. 



Greater Black-backed Gull. Dresser, viii. 427. 

 Mouette a manleatinoir. Temniinck, Manuel, ii. 760, iv. 471. 



Old black-backed individuals of this powerful and stately Gull are 

 specially numerous here during the stormy months of autumn and 

 winter ; during violent westerly gales flocks of hundreds may fre- 

 quently be seen assembled under the lee side of the island. All such 

 liirds display the dark spots on the head and neck characteristic of 

 the winter plumage. Early in the spring and in tine weather the 

 birds are fond of sunning themselves in large numbers on the flat 

 northern foreshore of the dune. Individuals in the perfect, pure 

 white summer plumage are met with extremely rarely ; on the other 

 hand, young birds in the first or second autumn of their lives, are of 

 very frequent occurrence. 



This bird is found as a breeding species in Greenland, Iceland, 

 on the coasts and islands of Great Britain, and from central to 

 northern Scandinavia. In Russia it occurs more sparingly 

 and scattered, but ranges as far as the estuary of the Petchora. 

 It does not appear to occur in northern Asia; but breeds in 



2m 



