Differences in Climbing and swimming strategies

INTRODUCTION:

Based on the physical composition of their environment, animals are often required to perform various modes of locomotion. However, within each mode there may be several different strategies that an animal can employ. It is unknown whether these strategies differ in the level of performance and how such potential differences are mediated by body and limb kinematics.

Such performance differences may have behavioral and ecological implications where, for example, if one strategy had a higher velocity and the other has higher acceleration an animal may use the former to pursue prey and the latter to escape predators. In basilisk lizards (Basiliscus vittatus), climbing can be achieved with either the limbs being used synchronously, akin to hopping up a vertical surface, or asynchronously, where the left and right hind limbs are out of phase. In swimming locomotion, these lizards will often perform swimming by axial undulation with their limbs folded against their body, but they can also adopt paraxial swimming, using their hindlimbs to kick. This study aims to test (1) if the maximum and average velocities and accelerations and axial kinematic variables differ between the two strategies in each mode of locomotion and (2) if higher performance in one strategy correlates with increased frequency of use of that strategy over the other.

We find that there are no differences between performance within each strategy and that alternating for climbing and undulating for swimming are the more frequently used strategies. Additionally, there are few climbing kinematic differences, indicating that although the two strategies are very distinct, basilisks still climb in the same way. For swimming, there are many more kinematic differences.