Black-necked cranes are seen at the Dashanbao state nature reserve of black-necked cranes in Yanjin County, southwest China's Yunnan Province, Dec. 18, 2012. Over 1,700 black-necked cranes chose to spend this winter at the reserve, 500 more than last year. (Xinhua/Chen Haining)

Black-necked cranes are seen at the Dashanbao state nature reserve of black-necked cranes in Yanjin County, southwest China's Yunnan Province, Dec. 18, 2012. Over 1,700 black-necked cranes chose to spend this winter at the reserve, 500 more than last year. (Xinhua/Chen Haining)

Black-necked cranes are seen at the Dashanbao state nature reserve of black-necked cranes in Yanjin County, southwest China's Yunnan Province, Dec. 18, 2012. Over 1,700 black-necked cranes chose to spend this winter at the reserve, 500 more than last year. (Xinhua/Chen Haining)

Black-necked cranes are seen at the Dashanbao state nature reserve of black-necked cranes in Yanjin County, southwest China's Yunnan Province, Dec. 18, 2012. Over 1,700 black-necked cranes chose to spend this winter at the reserve, 500 more than last year. (Xinhua/Chen Haining)

Black-necked cranes are seen at the Dashanbao state nature reserve of black-necked cranes in Yanjin County, southwest China's Yunnan Province, Dec. 18, 2012. Over 1,700 black-necked cranes chose to spend this winter at the reserve, 500 more than last year. (Xinhua/Chen Haining)