Sooty Shearwater Ardenna grisea
Status : Fairly common
Distribution : Mainly migration visitor off the Pacific coast of Middle-Northern Honshu and Hokkaido, Sea of Okhotsk coast of Hokkaido (mainly Apr-Nov), off the Sea of Japan coast of Honshu (mainly spring). Poorly known in the area off the Pacific coast and East China Sea coast of Western Honshu and Okinawa Pref. Uncommon but regularly seen around Japan in winter. They are seen in swarms of hundreds, at times thousands.
Tips : Mainly adults molting primaries are seen in Apr to May around Japan. The number of fresh juveniles begins to increase in May.