Multitudes of waterfowl such as wild geese, ducks and swans come over for wintering. Recently, however, water pollution has threatened the environment of waterfowl. Uchi-numa Environment Conservation Foundation works on a comprehensive conservation project. In addition, many research and educational activities are being conducted with centering three Sanctuary Centers. 40ha Yatsu-higata is connected to Tokyo Bay by two channels where the tide flows in and out.
Tidal flats appear regularly.
This area is surrounded by residential areas, schools and roads. It is one of a few very important visiting places for migratory birds such as Plovers and Sandpipers. As the flat is located about 2km inside the present coastline of Tokyo Bay, the tidal flat which appears in this area remains while others along the coast disappear at high tide. Tens of thousands of waterfowl of more than 100 species visit this tidal flat. The city of Narashino established the Yatsu-higata Nature Observation Center in July 1994.