Hyperolius argus (Anura) in Natal: taxonomy, biogeography and conservation

Abstract

A high degree of variation in the colour pattern of Hyperolius argus Peters, including sexual dichromatism and a marked cline, has led to much taxonomic confusion. This East African species extends down the Natal coastal lowlands as far south as Durban. It has been assigned to H. punctlculatus (Pfeffer) in Natal. In a discussion of Mozambique and Natal material, this assignation is shown to be incorrect. The probable holotype of Cope's cinctiventrls is considered to be a synonym of argus. There is some evidence that populations of argus intergrade with semidiscus Hewitt in Natal, and the occurrence of semidiscus on the periphery of the argusrange is discussed in relation to the ‘central-marginal’ model of biogeographical patterning. It has not been possible to determine the relative vulnerability to habitat disturbance of argus compared to any other amphibian species, but the conservation prospects of this species at the southern end of its range currently seem extremely poor.