A whooper swan flies above the lake in Rongcheng, east China's Shandong Province, Dec. 28, 2008. Having nearly 10,000 migrating whooper swans here every winter, Rongcheng becomes a famous place for whooper swans to spend winter. The Rongcheng Nature Reserve covers an area of 1,675 hectares. The nature reserve is built to protect everglade and birds that are in danger.[Liu Xingguo/China.org.cn]