Rhinoceros Auklet

Rhinoceros Auklet (Cerorhinca monocerata) is a chunky North Pacific auk with a thick orange bill and a horn-like bill ornament during breeding. 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 using its wings to pursue schooling fish and nests in deep earthen burrows on offshore islands. 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).