Dataset for: Numbers, neighbours and hungry predators: what makes chemically defended aposematic prey susceptible to predation?

Many chemically defended aposematic species are characterised by relatively low toxin levels, which enables predators to include them in their diets under certain circumstances. Knowledge of the conditions governing the survival of such prey animals – especially in the context of the co-occurrence of similar but undefended prey, which may result in mimicry-like interactions – is crucial for understanding the initial evolution of aposematism.
In a one-month outdoor experiment using fish (the common carp Cyprinus carpio) as predators, we examined the survival of moderately defended aposematic tadpole prey (the European common toad Bufo bufo) with varying absolute densities in single-species prey systems or varying relative densities in two-species prey systems containing morphologically similar but undefended prey (the European common frog Rana temporaria). The density effects were investigated in conjunction with the hunger levels of the predator, which were manipulated by means of the a...