Roseate Tern

Roseate Tern (Sterna dougallii) is a graceful pale tern with very long tail streamers, black cap and a dark bill that develops red at the base. 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 plunge-dives for small schooling fish and nests colonially on islands, often alongside other tern species. 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).