Black-headed Gull

Black-headed Gull (Chroicocephalus ridibundus) is a small gull with a chocolate-brown breeding hood, red bill and legs and pale grey wings with black tips. 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 feeds on insects, fish and scraps around wetlands, fields and coasts and breeds colonially beside shallow freshwater. 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).