Red-throated Loon

Red-throated Loon (Gavia stellata) is the smallest loon, with a slim slightly upturned bill and, in breeding plumage, a grey head and chestnut-red throat patch. 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 breeds beside tundra pools and northern lakes, winters mainly in coastal waters and dives from the surface to pursue small fish and aquatic invertebrates. 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).