Freshwater turtles reveal personality traits in their antipredatory behaviour

Animals respond to predation risk with antipredatory behaviours that may disclose the presence of different personality traits among individuals in a population, and how populations may differ for the expression of those traits. Variation among individuals is a necessary condition for the evolution through natural selection and inter-individual behavioural differences may be selected in different environmental situations. We tested whether individuals of two freshwater turtle species, Emys orbicularis and Mauremys leprosa, show consistent risk-taking behaviour when exposed to the presence of a potential predator. In an outdoor experimental setting, we simulated a predatory attack by overturning a turtle onto its carapace and recording three different behavioural response variables. Our results showed clear differences between species. The appearance time was highly consistent over the trials for both species, but was shorter for E. orbicularis and very long for M. leprosa. Waiting time was consistent only for females of E. orbicularis while M. leprosa did not show repeatability and had significantly longer waiting times. The number of failed righting attempts, likely being partially dependent on turtle individual performance, was highly consistent during the experiment for both species. The hiding behaviour in both species of freshwater turtles was consistent over time and, therefore, could be regarded as a personality trait. However, the differences in waiting times consistency suggested possible differences in defensive strategies between sexes and species.