Distribution of veld rat sibling species Aethomys chrysophilus and Aethomys ineptus (Rodentia: Muridae) in southern Africa

Abstract

Sibling species Aethomys chrysophilus (de Winton) and Aethomys ineptus Thomas and Wroughton are indistinguishable in external morphology. Although their combined geographic range extends over a large area of southern Africa, their respective distributions are uncertain. We have assembled a database that includes all known positively identified specimens from the literature, as well as those recently collected by the authors in South Africa. Based on these specimens, we suggest that A. chrysophilus occupies most of the combined range, reaching its southern limit in northern South Africa, primarily in low elevations of the Limpopo River drainage. The remainder of South Africa is occupied by A. ineptus, which occurs at higher elevations in north central South Africa but expands into lower elevation habitats in the southern portion of its range. Although mostly parapatric, their ranges are known to overlap west of Pretoria (Magaliesberg region of North West Province) and west of the Soutpansberg in Limpopo Province. However, they are known with certainty to be syntopic at only one locality (Langjan Nature Reserve, Limpopo Province). Further research is needed to determine the zone of parapatry in Mozambique, Botswana and Namibia.

Key words: Aethomys, sibling species, geographic range, southern Africa.