Wood Warbler

Wood Warbler (Phylloscopus sibilatrix) is a bright leaf warbler with green upperparts, lemon-yellow throat and eyebrow, white belly and long pointed 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 field comparisons with similar species in the same habitat (Wikipedia, general species account).

It breeds in mature open-canopied woodland across Europe and western Russia, gleaning insects from foliage and nesting on the ground before migrating entirely to tropical Africa. 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).