Large, nondescript, long-tailed, long-billed wetland warbler. Primary habitat is papyrus swamp, though sometimes uses other types of reedbeds and wet scrub. Quite shy and secretive. Sings frequently, a slow and low-pitched mix of both rasping notes and more musical notes that ends in a trill. Similar to Lesser Swamp Warbler, but larger and longer-billed, lacking a pale eye-stripe. Also similar to Great Reed Warbler, but shorter-winged, darker, and grayer, without an eye-stripe.