Black-browed Reed Warbler

Black-browed Reed Warbler (Acrocephalus bistrigiceps) is a small warm-brown reed warbler with a bold pale eyebrow topped by a narrow black stripe. 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 from eastern central Asia and Russia through China to East Asia, foraging low inside undisturbed reedbeds for insects and migrating to Southeast Asia for the non-breeding season. Its movements and social behaviour vary through the year, with breeding birds generally more dispersed and non-breeding birds gathering where food is concentrated. The Korean vertebrate catalogue used for this guide records the species in South Korea (Wikipedia, general species account; Wildlife of Korea occurrence records).