Little Tern

Little Tern (Sternula albifrons) is a tiny tern with narrow wings, white forehead, black crown and a yellow black-tipped bill in breeding plumage. 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 hovers and plunge-dives for small fish and nests colonially on bare sand or gravel near water. 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).