Integrating isotopic and nutritional niches reveals multiple dimensions of individual diet specialisation in a marine apex predator

Dietary specializations are important determinants of ecological structure, particularly in species with high per-capita trophic influence like marine apex predators. These species are, however, among the most challenging in which to establish spatiotemporally integrated diets. We introduce a novel integration of stable isotopes with a multidimensional nutritional niche framework that addresses the challenges of establishing spatiotemporally integrated nutritional niches in wild populations, and apply the framework to explore individual diet specialization in a marine apex predator, the white shark (Carcharodon carcharias). Sequential tooth files were sampled from juvenile white sharks to establish individual isotopic (δ-space; δ13C, δ15N, δ34S) niche specialization. Bayesian mixing models were then used to reveal individual-level prey (p-space) specialization, and further combined with nutritional geometry models to quantify the nutritional (N-space) dimensions of individual specializ...