Cutting the cost of crouching: Over‐ground and tunnel locomotion in a tunnel specialist

Abstract

The physical constraints of tunnels present a considerable challenge to the animals that must navigate through them and still maintain the ability to efficiently travel over‐ground. Mustelids appear to be adapted for moving in the confined spaces of tunnels and burrows, as they possess elongate, flexible bodies with relatively short limbs. To investigate the relative performance of the mustelid bodyplan in tunnel environments, we studied various performance metrics of locomotion of the domestic ferret (Mustela putorius furo) in a height‐constrained chamber and compared to unrestricted over‐ground conditions. We synthesized these data with separate studies of gait analyses, whole body mechanics, histology, energetic, and electromyography to link tissue level functional morphology to whole‐animal performance. Despite a marked change in posture when ferrets enter tunnels, voluntary gaits and speed are unchanged, and oxygen consumption increases only slightly. Our analysis suggests that, in addition to the more obvious derived features of the musculoskeletal system, mustelids are also physiologically well suited for crouched locomotion.Grant Funding Source: none