This species ranges from Swellendam in the Western Cape Province in South Africa, east and north to the Tugela River basin in KwaZulu-Natal, and the lowlands of southern Swaziland. It is absent from higher altitudes along the Mpumalanga and Kwa-Zulu Natal escarpment, where it is replaced by its sister-taxon, Cacosternum parvum. It occurs up to at least 1,400 m asl, perhaps higher. Records from Mozambique require clarification (E. Scott pers. comm.).
Habitat and Ecology
It inhabits a wide variety of vegetation types, including fynbos heath land, savannah, shrubland, grassland, farmland, plantations, rural grassland, degraded forest and urban areas, occurring in areas of relatively high rainfall. It breeds in vleis and deeper pools in open wooded grassland areas, in thick reed beds, and in dense grassy verges of ponds. Its habitat preferences are generally more restrictive than those of Cacosternum boettgeri. During dry periods, these frogs aestivate below the surface, or under logs and stones, sometimes emerging in large numbers after heavy rain.
It is one of the most common frogs in its range, and can be heard calling from almost every substantial rut, drainage ditch and puddle in the wet season.
It is an adaptable species and it appears not to be threatened.
It occurs in many protected areas.
Red List Status
Least Concern (LC)
Listed as Least Concern in view of its wide distribution, tolerance of a broad range of habitats and its presumed large population.
We follow Scott (in press) in considering the subspecies, Cacosternum nanum parvum, as a distinct species. Specimens from north-eastern Kwa-Zulu Natal have been found which have a different call, and might represent another undescribed species (E. Scott, unpublished data).
IUCN SSC Amphibian Specialist Group 2013. Cacosternum nanum. The IUCN Red List of Threatened Species 2013: e.T58070A3064515. http://dx.doi.org/10.2305/IUCN.UK.2013-2.RLTS.T58070A3064515.en .Downloaded on 19 January 2019