A flock of black-necked cranes fly in the sky at Caohai National Nature Reserve in Weining County, southwest China's Guizhou Province, Nov. 21, 2012. Some 40,571 migratory birds have arrived here to get through this winter as of Nov. 21, according to the administrative bureau of the natural reserve. It is anticipated that the total number of migratory birds is able to exceed 100,000 by February of 2013. Caohai Lake is the largest and most important wetland of southwest China, providing wintering place for black-necked cranes, the only plateau crane left in the world, and inhabited by more than 100 bird species.
