Styan's Grasshopper Warbler

Styan's Grasshopper Warbler (Helopsaltes pleskei) is a secretive olive-brown grasshopper warbler with pale underparts, a long rounded tail and a fine 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 breeds in coastal scrub and swamp from eastern Siberia and Korea southward through nearby islands, feeding on insects within dense cover before wintering in southern China. 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).