Pallas's Grasshopper Warbler

Pallas's grasshopper warbler, also known as the rusty-rumped warbler, is an Old World warbler of the genus Helopsaltes. The adult has a streaked brown back and whitish-grey underparts, unstreaked except on the undertail, and young birds are yellower below. It is very like the common grasshopper warbler but slightly larger, with white tips to the tail and tertials and a warmer brown rump. It is a rare migrant in Sri Lanka (Wikipedia, general species account).

It breeds in the eastern Palearctic from the Altai, Mongolia and Transbaikalia to north-eastern China, the Korean Peninsula and the Sakhalin and Kuril Islands, and winters from India eastward to Indonesia. Four to seven eggs are laid in a ground nest in grass. The song is not the mechanical, insect-like reeling of the common grasshopper warbler but an inventive, Acrocephalus-like melody. SoIB 2023 rates it a Moderate conservation priority, a winter migrant of wetland with a Restricted range of about 19,400 km² and insufficient data on trends (Wikipedia, general species account; SoIB 2023).