Page:Mongolia, the Tangut country, and the solitudes of northern Tibet vol 1 (1876).djvu/182

 three feet thick. It does not entirely thaw till the first half of May.

Situated in the midst of the arid plains of Mongolia, Lake Dalai-nor serves as a great rendezvous for migratory birds belonging to the orders Natatores and Grallatores. In the beginning of April we found large numbers of ducks, geese, and swans here; divers, gulls, cormorants, less numerous, as were also cranes, herons, spoonbills and avosets. The two latter kinds and others belonging to the same order (Waders) first appeared in the second week of April; birds of prey and small birds were very scarce.

For a detailed description of the flight and habits of these birds I must refer the reader to the second volume of this work, which will be especially devoted to the Ornithology; for the present I will only add that all birds of passage hasten their flight across