Seabird colonies of the Nakanogami Island, Ryukyus

Abstract

1. Results of investigations of seabird colonies on Nakanogami I., 16km SW of Iriomote I., S. Ryukyus, made by the author on 8 June, 1965 and 8 Aug. 1967, are reported, with notes on the geology, fauna, flora and history of research.2. The seabird colonies, with the estimated population of some 50, 000 birds, consisted of Sterna fuscata 75%, Calonectris leucomelas 15%, Anous stolidus 7%, Sula leucogaster 3%, and Sula dactylatra and Sterna sumatrana were observed. Albatrosses, formerly reported were not found.3. This island is of particular importance, along with Senkaku Is., as a seabird breeding place in the Ryukyu chain and has been authorized as a Natural Monument, as the result of this investigation.4. Being close to Iriomote I., it is easier for protective control than Senkaku Is. But egg-poachers from surrounding islands are still causing considerable damage and protective measure should be taken seriously.