114 ANSERIFORMES chap. 



ally-submerged position with erect tail when feeding is known 

 to every one. The various Swans have a whooping, trumpet-like, or 

 hissing note ; that of Geese is a harsh cackle, a gaggling sound, a 

 clang or a " honk." Ducks do not always c[uack, but have whistling 

 or grating cries in addition. The usual food is vegetable, consisting 

 of grass, Chara, Zoster a, Ulva, and other plants ; but Mergansers 

 live chiefly on fish, and the bill of fare is varied by grain, pulse, 

 berries, frogs, insect -larvae, worms, molluscs, and crustaceans. 

 The nest is placed on the ground in thick herbage, or some- 

 times almost in the water ; holes in banks, hollow trees, or even 

 branches at a slight elevation being chosen in certain cases : it is 

 composed of heather, grass, moss, leaves, or rarely seaweed and 

 twigs, and is lined with down, added gradually from the parent's 

 breast during incubation. The eggs, which vary in number from 

 two {Biziura) to about a dozen, are smooth and hard-shelled, with 

 a plain wliite, creamy, or green coloration, and are commonly covered 

 when left. The young return for a time to the nest at night, and 

 are carefully tended by the female, who is occasionally assisted 

 by the male, especially in Swans. It is not certain how tree- 

 building Ducks convey the nestlings to the water, though it has 

 been stated that they are carried in the bill ; but it is no 

 uncommon sight to see ducklings and cygnets climb upon their 

 mother's back and hide beneath her wings when danger threatens. 

 The sexes in Swans and Geese are usually alike, though ex- 

 ceptions occur, as in Chlotphaga ; in Ducks the male is generally 

 much the finer bird, and has peculiar decorations, such as the 

 elongated scapulars and rectrices of Harelda and Dafila ; the 

 sickle-shaped secondaries of Eunetta, Heniconetta, Arctonetta, and 

 Somateria ; the stiff feathers on the face in the last three and 

 Caviptolaemus ; the curly tail of Anas hoscas ; the crest, ruff, and 

 " sail " of Aex galericulata ; or the crests of many Fuligulinae and 

 Merginae, Some females have similar but less striking adornments. 

 Among the many instances of fine coloration may be mentioned 

 the Eed-breasted and Emperor Geese, the Harlequin, Mandarin, 

 Pink-headed and Shoveller Ducks, the Sheld-Drake (Fig. 34), 

 and the Goosander ; while most Swans are pure white. The blue, 

 green, or white speculum or wing-bar in various Ducks adds 

 greatly to their appearance. The young are comparatively dull, 

 the nestlings being thickly covered with yellowish down, furnished 

 with barbs and barbules ; the colour is, however, whitish or grey 



