Spotted Redshank

Spotted Redshank (Tringa erythropus) is a slim long-legged shorebird that becomes almost entirely black in breeding plumage and pale grey in winter. 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 wades and swims in shallow wetlands, sweeping its fine red-based bill for insects, crustaceans and small fish. 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).