The Cape Grassbird uses dense grass, restio, and fern cover in southern Africa. The BDI species account describes adults' rusty head and long tail, as well as their ground foraging.
BDI reports no plumage difference between the sexes. In adults, the forehead, crown, and nape are rusty red with dark streaks, and the long rusty-red tail is strongly graduated. The breast and flanks have dark streaks.
It uses dense grass, restios, and ferns and searches mainly on the ground for insects and other small prey. This is the regional ecology described by BDI, not proof that every population uses identical vegetation.
An extinction-risk assessment has not been added yet.