The Madagascar Swamp Warbler feeds on insects while moving among wetland plants. It is widespread on Madagascar, absent from the far north, and less common in the dry south.
It is slender, with short rounded wings and a long graduated tail. Its back, wings, and tail are dark grey-brown to dark brown, while the underside is greyish white. The sexes are similar; juveniles may lack streaks on the throat and breast.
It climbs reed stems and makes short flights between nearby clumps while searching for insects. It is usually solitary and secretive; its breeding habits are not well known.
An extinction-risk assessment has not been added yet.