Regional variation in morphometric characters in the angulate tortoise, Chersina angulata , from South Africa

Abstract

VAN DEN BERG, P., and E.H.W. BAARD. 1994. Regional variation in morphometric characters in the angulate tortoise, Chersina angulata, from South Africa. J. Herpetol. Assoc. Afr. 43: 28–32. Previous authors claimed that regional differences in body size, gular shield length and plastron concavity occur in the angulata tortoise, Chersina angulata, but no statistical evidence in support of these claims was provided. We obtained comparative data for the angulate tortoise from three regions in the Cape Province, namely the eastern Cape, the southwestern Cape and Namaqualand. Our data suggest that males from the three regions do not differ significantly in adult body size. Southwestern Cape females are, however, significantly smaller than those from the other two regions. Sexual dimorphism in body size, size of the gular shield and plastron concavity is well-developed in this species, although no significant difference in body size was found between males and females from Namaqualand. A similar pattern of geographical variation in body size was reported for at least one other reptile species in the western Cape Province, but more detailed analyses of all life history aspects of the angulate tortoise are necessary to fully understand the observed pattern.