RED-THROATED DIVER. 187 



to close in at the end of July, the pair of birds which fre- 

 quented our lake, used to take long flights overhead, flying at 

 a tremendous rate with their long necks outstretched^ and 

 looking, in the dim twilight, like large Ducks. 



Mr. Ogilvie Grant writes to me : — " As far as I have 

 observed in Scotland, the habits of the Black-throated Diver 

 are quite similar to those of the Red-throated Diver, on 

 which I send you a note, but C. ardicus never breeds on 

 the small lochs. All the nests I have seen have been placed 

 on the sloping banks of islands in the larger lochs, where trout 

 are to be caught in plenty." 



Nest. — When in the water itself, the nest is simply made of 

 dead grass and water-plants^ but when on land there is no 

 nest at all, or simply a few pieces of fresh sedge. 



Eggs. — Two in number. Ground-colour clay-brown or 

 olive-brown, sometimes light or very dark chocolate brown. 

 The black spots are scattered over the whole surface, and are 

 equally distributed, the underlying spots being black or greyish- 

 black, and scarcely to be distinguished from the overlying 

 ones. The dimensions of the eggs— axis, 3'2-3'5 inches; 

 diam., i-9-2'2 — overlap those of the Great Northern Diver, so 

 that large eggs of C. ardicus cannot be distinguished from 

 small ones of C. giada/is. Too much care, therefore, cannot 

 be taken in their identification. 



IV. THE RED-THROATED DIVER. COLYMBUS SEPTENTRIONALIS. 



Colymhus septentrionalis, Linn. Syst. Nat. i. p. 220 (1766); 

 Macgill. Brit. B. v. p. 301 (1852); Dresser, B. Eur. 

 viii. p. 621, pi. 628 (1876); B. O. U. List Brit. B. 

 p. 202 (1883) ; Saunders, ed. Yarrell's Brit. B. iv. 

 p. 112 (1884) ; Seebohm, Hist. Brit. B. iii. p. 412 (1885) ; 

 Saunders, Man. Brit. B. p. 699 (1889); Lilford, Col. Fig. 

 Brit. B. part xviii. (1891). 



{FlaU CXIV.) 



Adult Male.^General colour above ashy-brown, with an oily 

 green gloss, the feathers rather blacker in the centre, and 

 sparsely spotted or edged with white, these spots less distinct 



