2312 TUBE-NOSED BIRDS, DIVING BIRDS, PENGUINS 



and the presence of two elongated areas on the black back between the shoulders, 

 as well as others on the scapulars, marked by transverse white bands formed by 

 nearly confluent square spots. The breeding area of this species would seem to ex- 

 tend from the Hebrides and Scandinavia across Arctic Asia over the greater part of 

 America, although it does not include Greenland, Iceland, or the Orkneys. Some 

 writers regard, indeed, a variety inhabiting the Pacific coast of America as a dis- 

 tinct species, although this seems scarcely justifiable. Finally, the smallest, as well 

 as the commonest species is the circumpolar red-throated diver ( C. septentrionalis) , 

 so named from the presence of a patch of reddish gray extending down the throat 

 of the adult in breeding plumage. On the upper parts the plumage is blackish 

 brown in color, with a comparatively small number of spots, the head and sides of 

 the neck being ashy gray, while the nape is marked by streaks of black, gray, and 

 white. Young birds, in which the throat patch is lacking, are much more fully 

 striped. Although it does not breed at the present day in Great Britain to the 

 south of Scotland, remains of this diver, discovered in the superficial deposits of the 

 east coast, suggest that it was formerly a resident in this part of England, when 

 the climate was colder. 



Feeding almost exclusively on fish, and during the winter being oceanic in 

 their habits, the divers resort to inland lakes for the purpose of nesting. Unlike 

 the auks, they are not gregarious, consorting only in pairs, and these generally 

 keeping far apart from one another. Although they are strong on the wing, the 

 backward situation of their legs renders the divers extremely ill adapted for moving 

 upon land, where they walk with the greatest difficulty and ungainliness. Accord- 

 ingly, in order to avoid the necessity of making the attempt, the slight nest is 

 always constructed close to the water's marge, so that the sitting bird can at any 

 moment resort to her native element by merely sliding downward from her sitting 

 place. In contrast to their awkwardness on land, is the extreme agility displayed 

 by the divers both on and beneath the surface of the water. They may, indeed, 

 be regarded as almost the diving birds par excellence, the great northern diver 

 having been stated to remain below the surface for a period of eight minutes, and 

 all the species will readily take a baited hook while diving. Seldom seen on the 

 wing except during the periods of migration, divers fly in a straight, arrow-like 

 course, somewhat after the manner of ducks. The notes of all the species are harsh 

 and grating. Arriving at its breeding haunts in the Arctic regions, about the end 

 of May or beginning of June, synchronously with the breaking up of the ice, the 

 great northern diver forthwith sets about the work of nesting. For choice, an island 

 is selected, but, failing this, the shelving shore of some lonely lake, or even of a 

 mountain tarn, is taken for a site. The nest, which is constructed of grass and 

 sedge, is placed in an exposed position, where the sitting bird may readily receive 

 warning of approaching danger, upon which it takes at once to the water. This 

 might at first sight seem fraught with danger to the eggs; but it appears that the 

 safety of these is generally sufficiently assured by their protective resemblance to 

 their inanimate surroundings, their color being dark brown speckled with blackish. 

 The usual number of eggs in a nest is but two, and both sexes take their share in 

 the work of incubation. 



