Curlew Sandpiper

Curlew Sandpiper (Calidris ferruginea) is a slim sandpiper with long downcurved bill and deep rusty-red breeding underparts. 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 on Siberian tundra and migrates to tidal flats and saltpans, probing for insects, worms and crustaceans. 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).