The wintering ground of Roseate terns which breed as summer birds in Japan was not known despite nearly 30 years of research.However, the mystery was solved at last when Roseate terns with Japanese bands were recovered in the southern part of the Great Barrier Reef in winter 2002.The nesting numbers of Roseate terns in the surrounding islets of Okinawa island have been declining for the past few years.We should find ways such as establishing sanctuaries on breeding islands to co-exist with this species which serves as a bridge between Japan and Australia.