This species ranges from the KwaZulu-Natal Province in eastern South Africa, northwards into Swaziland, Zimbabwe, Mozambique and southern Malawi (Chikwawa), and then into Tanzania and southern Kenya. Up to 1,800 m in eastern Zimbabwe.

There are three subspecies, O. c. crassicaudatus is known only from the KwaZulu-Natal region; O. c. kirkii Gray, 1863, ranges from Massangena, Mozambique, in the south to southern Malawi in the north; and O. c. monteiri is found in the Brachystegia miombo woodland zone from Angola in the west, to Zambia, Malawi and northern Mozambique in the east and from here north to Rwanda and western and south-eastern Kenya.

Some taxonomic authorities states that O. c. monteiri can be split into two groups with a monteiri group present from Angola, through the southern Democratic Republic of the Congo, Zambia, Zimbabwe, northern Mozambique, Malawi and southern Tanzania (Tabora). The distribution of the argentatus grouping is unclear, but it has been recorded from Rwanda, Kenya and Tanzania.