Swinhoe’s Storm-Petrel Hydrobates monorhis
Summer visitor; mid May-Oct. Endemic. Opportunities to seen at sea are rare, because small population and foraging areas are far off from the breeding sites.
Breeding sites are confirmed on Sangan-jima (Iwate Pref); probably a few pairs, Onbase-jima (Izu Is); 280 nests in 2017, Hachijyo-kojima (Izu Is); 110 nests in 2017 , Kutsu-jima (Kyoto Pref); 240 nests in 2016, Hoshigami-jima (Shimane Pref); 13 nests in 2016, and Koyajima (Fukuoka Pref); 30 nests in 2016. Recent years, breeding has not been confirmed on Shiriyazaki (Aomori Pref) and Nanatsujima-oshima (Ishikawa Pref).