Inter-specific and inter-population variation in individual diet specialization: Do environmental factors have a role?

Individual diet specialization occurs when individuals consume only a subset of prey composing the whole population trophic niche. In our study, we assessed trophic specialization in five species of European cave salamanders (genus Hydromantes) from Sardinia (Italy), hypothesizing two potential (but not exclusive) causes. Our results showed that all the Hydromantes populations analyzed included "true specialists," and the scenario in which the availability and diversity of prey, rather than negative biological interactions, is more likely represents the major cause of individual specialization. We then successfully used environmental features (both climatic and vegetation) to predict the specialization in these salamanders.