Bradypterus baboecala

This long, round-tailed species is found in dense reeds and riparian vegetation and can be told from its fellow warblers by its buff undertail, streaked breast and distinctive song.

This is definitely a skulker that you hear far more often than you see. After listening to it for some months without seeing it, I finally recorded it in October 2011 while birding Marivale Bird Sanctuary with Skye Hartog.