invading army. In squadrons and battalions they march over the fields of 

 winter wheat, uprooting and devouring the tender seedhngs, till the ground is 

 left bare and brown behind them. Whether taken with rifle or shot gun, 

 stalked, or shot as they pass in long chains overhead, they afford excellent 

 sport. Closely allied to the bean goose is the grey lag goose {Anser ferus). 

 The latter is a much rarer bird in North China, and is only met with in the 

 more out of the way places, such as the lonely marshes of the Ordos Desert. 



The ruddy sheldrake {Casarca ferruginea) is extremely common in some 

 places. We found this duck most numerous on the Hsi-an Fu plain in South 

 Shensi and ip Honan. Here they were seen in pairs in every field, but at 

 Yii-lin Fu they occurred in large flocks. We seldom paid any attention to 

 these birds as they were easy to shoot and their flesh was coarse and oily. 

 The common sheldrake (Tadorna cormta) is only occasionally met with. 

 The wild swan {Cygnus ferus) is also an occasional visitor. 



Coming to the ducks we find that the commonst species are the mallard 

 {Anas boscas), the teal {Nettion crecca), the pochard {Nyroca fen'm), the shoveller 

 (Spatula clypeata), the golden eye (Clangula glauciori) and the pin-tail {Dafila acuta). 

 There are other less common species such as the exquisite mandarin duck 

 {Aex galericulata) and Swinhoe's duck {Anas zonorhyncha). 



Of all the foregoing the only species that remain north of Hsi-an Fu 

 throughout the winter are the mallard and teal. 



The mallard and Swinhoe's duck not infrequently breed in the marshes 

 of Shansi. 



The Baikal teal {Nettion formosum) may sometimes be seen during the 

 migratory season together with the smew {Mergus albellus), the red-breasted 

 merganser {Merganser serrator) , and the goosander {Merganser castor) . The red- 

 breasted merganser often remains for the winter, when it may be found in the 

 valleys of the high mountain ranges where open streams not infrequently 

 exist even in the dead of winter. 



It is but a step from ducks to waders and aquatic birds in general, in 

 which branch of bird life the provinces of North China are particularly rich. 



A small species of gull {Larus crassirostris) follows up the course of the 

 Yellow River and many of its larger tributaries. It may be seen flitting over 

 ponds and marshes wherever these exist. On the present expedition these 

 birds were noted in Shansi, on the T'ai-yiian plain, again on the Hsi-an Fu 

 plain in Shensi, and also near Lanchou, in Kansu. The tern is a summer 

 visitor only. 



The bittern {Botaurus stellaris), the heron {Ardea cinerea), the black stork 



106 



