Thick-billed Murre

Thick-billed Murre (Uria lomvia) is a large Arctic auk with black upperparts, white underparts and a stout bill marked by a pale gape line. Body shape, bill structure, plumage pattern and voice provide the strongest field characters. Age, sex and season may alter its appearance, so identification should combine several features and careful direct field comparisons with similar species in the same habitat (Wikipedia, general species account).

It dives deeply for fish and crustaceans and nests in dense colonies on narrow sea-cliff ledges. Its movements and social behaviour vary through the year, with breeding birds generally more dispersed and non-breeding birds gathering where food is concentrated. Japanese records place it within the country's documented avifauna as a resident, migrant or visitor (Wikipedia, general species account; Wildlife of Japan occurrence records).