Oriental Reed Warbler

Oriental Reed Warbler (Acrocephalus orientalis) is a large brown reed warbler with a strong bill, pale eyebrow and warm buff 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 in East Asian reedbeds, where it climbs sturdy stems, sings loudly from exposed tops and takes insects and other small prey; it migrates south to tropical Asia for winter. 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).