Lesser Yellowlegs

Lesser Yellowlegs (Tringa flavipes) is a slender North American shorebird with bright yellow legs and a fine, straight bill. 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 uses freshwater shallows and mud margins, taking insects and other small aquatic prey while walking actively; its long migrations connect northern breeding grounds with southern wintering areas. 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).