Abstract:The Russian Far East is one of the most important breeding sites for birds in the world, and Anadyr on the Chukchi Peninsula is known as an important breeding site of the critically endangered Spoon-billed Sandpiper (Calidris pygmeus). In order to carry out the Sino-Russia Bilateral Agreement on the Protection of Migratory Birds and Their Habitats, and to understand summer waterfowl community in Anadyr in the Russian Far East, we investigated the summer waterfowls in the southern part of Anadyr from June 25th to July 20th in 2017. The investigation covered four areas including Anadyr, seas from Anadyr to Beringovsky, Beringovsky, peripheral tundra area of Meinypilgyno and the adjacent seas (Fig. 1). With binoculars and monocular telescopes, the investigators carried out the investigation on land areas and water areas by belt transect method and line transect method. We recorded 35 waterfowl species belonging to 6 orders and 10 families, with 14 species as local breeders (see Table 1 with breeding activities and habitat). According to the banding and recovery data between China and Russia during 1976 to 2017 from the database of National Bird Banding Center, 11 species of waterfowls were recorded as migrants birds between China and Russia (Table 2), with their major breeding sites and stopover sites shown by the migration tendency chart drawn by ArcGIS, a geographic information system software (Fig. 2 for geese and ducks, Fig. 3 for waders and Fig. 4 for gulls and terns). Meanwhile, the reasons for the depopulation of Spoon-billed Sandpiper were analyzed based on the actual investigation of the breeding sites as well as relevant historic materials and literatures. Through the analysis of banding and recovery data, we suggest that (1) the Russian Far East area is closely related to the eastern coastal area and the Yangtze River Basin of China, such as the Poyang Lake and the Dongting Lake, as the East Asia – Australia bird migration route. Generally, Anseriformes birds and waders that overwinter in the eastern coastal area and the Yangtze River Basin of China will migrate to the Russia Far East areas, such as Khabarovsk, Sakhalin, Kamchatka Peninsula, Yakut, Chukchi, etc. for their breeding in summer. So the co-investigation and cooperation between China and Russia and the protection of bird habitats is very important. (2) There are two potential threats to the breeding population of Spoon-billed Sandpiper in Anadyr: [1] The flood formed by the melted ice and snow on the mountains in each spring flows into rivers, which leads to the rise of water level, generating risks of submerging the nesting ground of Spoon-billed Sandpiper in parts of their breeding sites; [2] Eggs and fledglings of many birds including Spoon-billed Sandpiper might be preyed on by natural enemies such as Corvus corax, Vulpes vulpes and Citellus dauricus. Meanwhile, the degradation of major stop-over and overwintering places along the migration route, environmental pollution and human activities are also important factors for the depopulation of Spoon-billed Sandpiper. The reclamation and degeneration of tidal flats in the eastern coastal area of China (e.g. the mudflats in Rudong County, Jiangsu Province) reduce the places for energy supplement and increase the risk for migration; the illegal hunting in Burma is the major reason for the reduction of overwintering population of Spoon-billed Sandpiper. Therefore, the study on the migration routes of Spoon-billed Sandpiper is one of the urgent topics today.