Understanding the diet and trophic ecology of apex predators is critical for effective ecosystem management, but analysis is generally restricted by their low abundance, threatened status, and, hence, available data. To address this knowledge gap for the White Shark (Carcharodon carcharias), we examined stomach content data (n = 225) and undertook preliminary stable isotope analysis (δ15N and δ13C) of muscle tissue (n = 21) of sharks sampled from KwaZulu-Natal, South
Africa. Summarized stomach content analysis (SCA) data indenti¢ed a size-based transition in diet, an increase in mammalian prey, and a corresponding decrease in teleost and elasmobranch prey with increasing size of shark. Multivariate analysis of SCA data by size class was signi¢- cant, but a high degree of overlap of functional prey groups across size classes was observed. The smallest sharks containing whale and seal prey were 194 and 209 cm precaudal length (PCL), respectively. Trophic position calculated from SCA data (TPSCA) ranged from 4.2 to 5.0 with sharks feeding across 0.8 trophic levels. Although TPSCA data were highly variable, there was a signi¢cant linear relationship with increasing size of shark. Similarly, there was a signi¢cant increase in δ15N values of muscle tissue with size of shark and feeding across 1.4 trophic levels was predicted. Sharks >200 cm PCL had highly variable δ15N muscle tissue values (minimum, 14.7; maximum, 16.8), possibly indicating multiple feeding strategies. For δ13C, the two smallest animals (124 and 134 cm PCL) had lower δ13C values relative to all other sharks except the largest individual. Because these sharks are newborn animals, this suggests interference of the maternal signature and may indicate that large individuals, including pregnant females, switch forage base and/or remain offshore for extended periods of time.