244 Order XVI 



Very closely allied is the more Arctic C. adamsi, a larger 

 bird with a greener tint on the head, a purplish hue 

 on the throat, a yellowish white bill, and more elongated 

 spots. It may breed all round the Pole, and certainly 

 does so in Novaya Zemlya, Arctic Siberia, and North 

 America west of the Great Slave Lake. Specimens have 

 occasionally been obtained in Britain. The habits of 

 both species are similar. The cry is a weird sort of 

 laugh or croak, uttered on the wing as the bird describes 

 wide circles round its breeding-quarters; its flight 

 resembles that of a large Goose, while it dives under 

 water at once if it is alarmed when swimming. Divers, 

 however, are not specially suspicious, and, particularly 

 when near the nest, allow persons to approach within 

 short distances. The fabric, built on an island or at the 

 edge of a lake, is of water-weeds, and may either be 

 a considerable pile or practically non-existent ; the 

 two big eggs are brownish olive with blackish spots. 

 In leaving and regaining the nest the sitting bird 

 usually shdes along rather than walks, making a distinct 

 track to the water. The food is of fishes, with crabs and 

 so forth from the sea, for Divers only frequent the land 

 in the breeding-season. 



The Black-throated Diver (C. arcticus) nests in the 

 north and west of Scotland down to the shires of 

 Perth and Argyll, in the Hebrides, and in the Orkneys, 

 as well as abroad from Iceland, the Fseroes, and 

 Scandinavia eastward to the Pacific. It does not seem 

 to occur to the north of the Arctic continent, but extends 

 to Arctic America as a paler-naped form. It is dis- 

 tinguished from the Great Northern Diver by its grey 

 crown and hind-neck, entirely black throat and chin, 

 divided by a small band streaked with white, and by 



