104 THE BIRDS OF MONGOLIA ETC. 



April and beginning of May. During migration it is not numerous at 

 Hanka, and is at least ten times as scarce as the following species, although 

 young birds are rather abundant there. 



268. QuERQUELULA CRECCA, L. Utka chiranha. 



During migration, in March, Q. crecca is extremely abundant in 

 S.E. Mongolia. At Lake Dalai-nor we fell in with large flocks, composed of 

 the present species and Eiinetta glocitans, but did not find it breeding any- 

 where in Mongolia, though in winter some individuals were observed at 

 Tsaidam, where the migration commenced on the 15th of February. At 

 Koko-nor it was the commonest of all Ducks in the month of March. 



At Lake Hanka, Q. crecca appears already early in March, but principally 

 at the end of the month, in such large numbers that, with the exception of 

 A. boschas, it is the most numerously represented species there. Only very 

 few remain to breed, as the extensive marshes do not offer them suitable 

 nesting-places. 



269. EuNETTA FALCATA, Pall. Utka kosatchca. 



In March and April it is common at Dalai-nor, and has been noticed by 

 us also in the Hoang-ho valley, where it also breeds sometimes, but apparently 

 does not occur at Koko-nor. 



At Lake Hanka it appears early in March ; but the principal migration 

 takes place late in that month or early in April, when this Duck is very 

 common, and usually forms flocks with other kinds, but very rarely alone. 

 Its voice is a tolerably loud and piercing whistle. 



It breeds numerously at Lake Hanka, but, like its congener, usually 

 late. 



