The Karoo Scrub-Robin Erythropygia coryphoeus, which has recently had the authorship of its scientific binomen adjusted from Sylvia coryphaeus Lesson, 1831, to the earlier Sylvia coryphoeus of Vieillot, 1817, following the findings of Rookmaaker (1989) - see also Brooke and Clancey (1990) - is a small sombrely coloured endemic robin of karoo scrub and acacia thickets of the southern parts of the Southwest Arid Zone of the Afrotropics. It is distributed from south-central Namibia from the Naukluft National Park and the northern Cape, south to the entire Cape south of the Orange R., extending east to the western limits of the Transkei at Cofimvaba (Quickelberge 1989), the western lowlands of Lesotho and the drier west of the Orange Free State to about 28° E. There is little evidence that it is other than mainly sedentary. It is closely allied to another scrub-robin, Erythropygia paena (Smith), with which it is sympatric from the basin of the mid-Orange R. northwards. The two species are in the main allopatric, but their ranges overlap widely in association with the transition of plant community facies from karroid type to the Acacia/grass country complex of the Kalahari ecosystem. There is no evidence that the species hybridize in their zone of sympatry where they are often to be encountered on the same ground. Their joint distribution pattern suggests that coryphoeus resulted from a primal colonising event and paena from a later one, the staggered radiation also involving the Rufous Scrub-Robin E. galactotes of the Palaearctic and the arid parts of the northern Afrotropics.