Common around Bonin Is and Volcano Is. Also few birds seen S Izu Is in summer, and E Honshu; off Choshi, Chiba Pref regularly Jun-Jul. Some Field Guides describe distribution including N Japan; around N Honshu and Hokkaido in summer. However, I think that it not be accurate because not seen regularly around these area except after typhoon passed. Breeding sites are confirmed on Bonin Is and Volcano Is.