Poorly known, small gray-brown bird with a large bill, a flat forehead, and a short, pale supercilium. Extremely similar to Blyth’s Reed Warbler, but the Large-billed Reed Warbler has a longer bill, longer legs, and slightly shorter wings. Breeds in damp scrubland at high altitudes. Migratory range and habitats are unclear. Song said to be faster, more complex than that of the Blyth’s Reed Warbler.