Swamp Grass Babbler

The swamp grass babbler, or swamp prinia, is a small bird of the Indian subcontinent averaging 17 cm long, big for a prinia. Adults are olive-grey above, slightly warmer on the back of the neck and upper back but less distinctly collared than the rufous-vented grass babbler, with greyish-white underparts, greyer on the flanks and perhaps slightly streaked, and faintly tawny off-white wing linings. Some authorities consider it a subspecies of the rufous-vented grass babbler (Wikipedia, general species account).

It moults into adult head and body plumage, keeping its flight feathers, about four to six weeks after fledging. The calls include a wheezy feez and a quiet, very rapid nasal rattle, and the song is a liquid, loud warble about 4 seconds long, comparable to a dunnock's. Like the rufous-vented grass babbler it skulks low in grass tussocks, hopping and threading its way through, often in small groups, feeding on insects. SoIB 2023 treats it as an Assam Plains endemic and rates it a High conservation priority, a resident and local migrant of wetland with a Very Restricted range of about 6,950 km² (Wikipedia, general species account; SoIB 2023).