Distinctive very dark bird with large feet, most often seen running up and down the sides of trees in dry forest, savanna, and moist lowland forest of northern Australia, where it is the only treecreeper species. Uniformly rich, dark brown, almost black, with white streaks on the throat. In flight. shows bold tan wingbars. The western subspecies (wellsi) has reddish-brown underparts. Call is a slow, repeated "pip pip pip," usually followed by a fast trill of the same note.