Beijing Wild Duck Lake, the largest wetland bird nature reserve in North China and the only one in Beijing, is located on the bank of Guanting Lake at the foot of the Badaling Great Wall in Yanqing District. It has a water surface of more than 1.5 million square meters. Due to the good natural environment here, it was approved by the municipal government as a municipal wetland bird nature reserve in Beijing in December 2000. Wild Duck Lake is located in the northwest of Yanqing District, Beijing, and belongs to the transition zone from the North China Plain to the Shanxi Plateau and the Inner Mongolia Plateau. It is backed by the Yanshan Mountains in the north, the Taihang Mountains in the south, and borders Huailai County, Hebei Province in the southwest. The majestic Badaling Great Wall is to the southeast. Wild Duck Lake is an artificial wetland composed of the Yanqing area of Guanting Reservoir and the flooded area and tidal flats below 479m above sea level around the lake. The total area of the reserve is 6,873 hectares, of which the wetland area is 3,939 hectares. It is the only wetland bird nature reserve in Beijing. After more than 50 years of development, it has formed a wetland ecosystem with rich animal and plant resources, high biodiversity and stability, and has become one of the important bird habitats in Beijing and even in North China. The reserve is rich in animal and plant resources. According to statistics, there are 389 species of higher plants in Yeya Lake Wetland, including 16 species of bryophytes, belonging to 9 families and 9 genera; 8 species of ferns, belonging to 5 families and 5 genera; 7 species of gymnosperms, belonging to 3 families and 5 genera; 358 species of angiosperms, belonging to 72 families and 212 genera. The total number of bird species in Yeya Lake is 264, including 6 first-class national protected animals (black stork, oriental white stork, white-headed crane, great bustard, golden eagle, white-tailed sea eagle), and 34 second-class national protected animals. There are 40 species of fish in 5 orders and 9 families, 5 species of amphibians in 1 order and 3 families, 7 species of reptiles in 3 orders and 4 families, 10 species of mammals in 5 orders and 6 families, 182 species of insects in 12 orders and 61 families, 63 species of protozoa, 35 species of rotifers, and 12 species of crustaceans in freshwater zooplankton.