Atlantic White Tern

Atlantic White Tern (Gygis alba) is an all-white tropical tern with black eye, slender black bill and translucent-looking wings. 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 comparisons with similar species in the same habitat (Wikipedia, general species account).

It catches small fish and squid at the sea surface and lays its single egg directly on a bare tree branch or ledge. 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).