THE BIRDS OF MONGOLIA ETC. 101 



male apparently does not assist the female in hatching ; but as soon as the 

 young are hatched, it most vigilantly watches them. The earliest young we 

 saw on the Suma-had mountains, on the 4th of June. 



In Mongolia this bird is tame ; but at Lake Baikal, where it has been 

 much pursued, it is very shy. 



263. Ma-RECA PENELOPE, L. Uthtt svias. 



Durinar mio-ration we found these Ducks in rather limited numbers at 

 Koko-nor, where they arrived about the 21st of March. 



At Lake Hanka they appear late in March or early in spring, and only 

 a few remain to breed. 



264. Dafila acuta, L. UtJca shilohvost. 



Is very common throughout Mongolia during migration — which takes 

 place in the end of March and the beginning of April, and late in August. 



Very large numbers of the present species were observed by us in spring 

 at Dalai-nor, where most likely part of them remain to breed. It is also 

 abundant on the lakes of the Hoang-ho valley. In Tsaidam the earliest birds 

 were seen on the 18th of February, and at Koko-nor in the first days of 

 March ; but towards the end of that month they had quite disappeared. At 

 Lake Hanka they arrive early in March ; but the principal migration takes 

 place in the end of that month, about which time these Ducks are extremely 

 abundant and usually mixed together with other kinds in large flocks, 

 although only very few remain to breed. 



265. Anas boschas, L. Utka hriakha. 



Is the most common of the family in S.E. Mongolia, where it breeds in 

 all suitable localities, but most numerously in the Hoang-ho valley ; and 



