Northern Fulmar Fulmarus glacialis
Status : Fairly common
Distribution : There are no breeding sites in Japan. Common to fairly common off the Pacific coast of from Hokkaido to north of Izu Islands, the Sea of Japan coast of from Hokkaido to San-in region, and the Okhotsk coast of Hokkaido (year-round; population size is bigger off the Pacific coast and the Okhotsk coast of Hokkaido in summer-autumun, off the Pacific coast of northern Izu Islands in winter.). Poorly known in the Sea of Japan but probably common off the Sea of Japan coast of from South Korea to Shimane Pref. at least in summer.
Tips : At times they are seen in swarms of hundreds. Dark morphs common around Japan. Light morphs are uncommon but getting common after 2010s (in my opinion).
We try to categorize the morph by Flood & Fisher (2016), and described in caption.
Flood B. & Fisher A., 2016. Multimedia Identification Guide to North Atlantic Seabirds:
Albatrosses and Fulmarine Petrels. Pelagic Birds & Birding Multimedia ID Guides, Essex.