Differences in locomotor performances between two sympatric species of freshwater turtles

Abstract

Animals whose ecological niches largely overlap within a habitat can get into intra-specific and/or inter-specific competition for some of the limited resources available. We hypothesise that differences in locomotor abilities might be a key component deciding which individual will gain the resource, especially in animals with limited agility, such as turtles. To address this hypothesis, we tested self-righting ability and releasing from a vegetation alike rope in two sympatric populations of turtles: Emys orbicularis and Mauremys rivulata. All individuals managed to complete the tests promptly (≤ 103 s). When overturned on their carapace, E. orbicularis had shorter inspecting time, as well as overturning time, indicating slight advantage in self-righting. On the other hand, both species were equally efficient to release from a rope attached to the front of their plastron. The inter-specific morphological differences indicate that muscular strength might be a good predictor of competitive relations among syntopic turtle species.