Common Guillemot Uria aalge
Common with breeding in Teuri-to (Hokkaido). The bird’s population is very small in Japan.
In 1960s their population was estimated to be about 8,000, but after that decreased sharply. In recent years the number of individuals has been gradually recovering due to projects for protect and multiplication. In 2017, 20 pairs (about 50 birds) was confirmed.
In the past, there were records of breeding in Yururi-to, Moyururi-to, Cape Ochi-ishi and Matsumae-kojima (above areas are in Hokkaido).
They are normally seen at off Hokkaido and rarely seen at off the north of central Honshu in the winter. Perhaps the reports that is seen at off Kanto Region are misidentifying Brunnich’s Guillemot.