THE TORTOISES (TESTUDINIDAE) AND TERRAPINS (PELOMEDUSIDAE) OF SOUTHERN AFRICA - THEIR DIVERSITY, DISTRIBUTION AND CONSERVATION

Southern Africa has the richest diversity of land tortoises in the wor ld, as well as an important radiation of pelomedusid terrapins. Total species richness has two epicentres, including the Transvaal lowveld a nd adjacent KwaZulu/Natal (owing to the prevalence of pelomedusid terr apins) and the Eastern and south-western Cape (owing to small testudin ids). The area encompassing Lesotho, Transkei and adjacent regions, la cks testudinids for unknown reasons. Archaeological data indicates tha t this gap is natural, and not the result of man-induced extinctions. Endemic species are clustered in the Cape, whilst the few threatened s pecies are more widely distributed. The majority of species is well pr otected in existing reserves. The small number of chelonian species in southern Africa and their relatively well-known distributions, test t he efficacy of an iterative reserve selection algorithm. The presence of many allopatric (or nearly so) congeneric species leads to the sele ction of iterative reserves that protect peripheral populations. To av oid this, marginal records and isolated, peripheral populations should be excluded from the analysis.