Anti-predator behavior in two brown frogs: differences in the mean behaviors and in the structure of animal personality variation

Predators are a major source of selection and preys have evolved the ability to flexibly respond to them. These responses often vary among species, because of their different evolutionary history, and among individuals, because of their different experiences. We analyzed both these sources of behavioral variation in two closely related brown frogs, Rana dalmatina and R. latastei. We raised tadpoles either with or without predators and tested them in open field trials both with and without predators. The effects of the raising environment were similar in the two species, whereas the effects of the testing arena differed. Both species decreased activity and increased speed and tortuosity with predators, but R. dalmatina moved always more and faster than R. latastei and it showed higher plasticity, larger variation among and within individuals, and relatively higher values in repeatability.