Also known as Ring-eyed Scoot, Sooty Guillemot
or Bridled Guillemot. Distantly related to Black and Pigeon Guillemots.
Similar in shape to Black and Pigeon Guillemots but noticeably larger (length av. 38 cm compared to 32-33 cm).
Adult plumage uniform sooty black with obvious white patches (lenses of the spectackles) surrounding the dark eyes. The white extends backwards as a post-ocular stripe (the arms of the spectackles). The black bill is heavier and more dagger-like than the cepphus guillemots, with obvious white feathering at the base. As with other cepphus, the legs are bright red (the Japanese name Keimafuri, means 'bird with red legs')
In non-breeding plumage, adults develop whitish underparts, extending up onto the neck and throat. In all plumages lacks oval white patches on the upper wing coverts, although may not eliminate some individuals of the Kuril Island subspecies of Black Guillemot (C. c. snowi).
Juveniles resemble non-breeding adults but tend
to be whiter, especially on the throat.
Where and When
Endemic to the northwest Pacific with 90% of the population found in the Sea of Okhotsk. Breeds on coasts of Northern Japan (Hokkaido and northern tip of Honshu), NE Korea, Sakhalin Island and coasts of Ussuriland and western Kamchatka. Total world population estimated at less than 75,000 pairs. Generally winters close to breeding grounds, although some dispersal to the south in winter.
On Hokkaido once very common around Teuri Island
(~3000 pairs) located in the very nortwest but numbers have declined dramatically
(50-60 pairs in 1999). Fairly secretive and tend not to approach nest sites
if humans or other predators are in the area - a contrast to Pigeon Guillemots
which in California will nest in man-made structures including hotel balconies
(pers. obs)! Also easily found on the Siretoko and Shakotan Peninsulas.
Entire Japanese population seems to be in decline. Adults gather off nesting
areas in March and chicks fledge in July and August. Breeding adults begin
molt in early July whilst still attending young. Non-breeding birds often
gather in the Tohoku region.