258 THE DIVING DUCKS 



4. Nest and Eggs. Where undisturbed the eider breeds in large colonies 

 on islands, partly no doubt for protection against its natural enemies, and places 

 its nest at a short distance from the water. In such colonies three or four nests 

 may be seen within a radius of a yard or two. In the Faeroes it has been known to 

 breed at a height of 1200 feet, and in the Shetlands nests have been found in the 

 hills at a considerable distance from the sea. Many nests are quite open, being 

 mere hollows in grassy spots or overgrown with dwarf willows (Salix lanata), bracken, 

 and rank vegetation, but in Scotland the shelter of a boulder is often sought, and 

 nests may be found in sheep-holes in stone walls. When selecting a nesting-place 

 the duck is accompanied by her mate, but the hollow is made by the female alone. 

 She lines the nest with dead grasses, bits of heather or seaweed, and later with 

 down. (PI. LXVUL) The down is as a rule plentiful, pale greyish brown with light 

 centres, and the nest feathers are figured in Brit. Birds, ii., pi. 2, fig. 13. (PL U.) 

 They are reddish brown, with two or sometimes three dark brown transverse bars. 

 The eggs vary in number to an extraordinary extent. Thus on the Fames, 

 though many nests contain only 4 or 5, others may contain 9, 11, 12, 13, 18, or 

 19 eggs ! which the watchers believe to be the produce of single ducks, though 

 this seems incredible. 1 On the Faeroes the number ranges up to 8-11. On the 

 eider farms in Iceland one rarely sees more than three eggs in a nest, but great 

 numbers are taken systematically for eating purposes. They are characteristic in 

 appearance, large, and often an elongated oval in shape, smooth in texture, with 

 some gloss, and ranging in colour from greenish grey to olive-green, yellowish olive, 

 or bluish green. Some eggs have what appear to be grease stains on them even when 

 freshly laid. Average size of 426 eggs by Gobel, 3-06 x 2-05 in. [77-9 x 52-2 mm.]. 

 (PI. S.) Incubation is performed by the duck alone, and lasts for 28 days accord- 

 ing to most observers, though Mr. F. G. Paynter estimates it at 31 days. The 

 breeding season at the Fames begins about 12th May, and on the Shetlands fresh 

 eggs may be taken from mid-May to mid-July. Only one brood is reared in the 

 season. [F. c. E. J.] 



5. Food. The main food of this species consists of marine Mollusca and 

 Crustacea. Among molluscs, large quantities of mussels (Mytilus edulis) are 

 swallowed entire, in some cases up to 2 inches in length. Periwinkles are also 

 commonly eaten : Mr. H. W. Robinson has found as many as twenty in one gizzard, 

 and also records limpets (Patella) and razor-shells (Ensis siliqua) up to the astonish- 



1 G. Bolam, Birds of Northumberland and the Eastern Borders, p. 406. 



