Meeting Abstract
To move through natural environments, animals must balance many potential performance demands, including speed, economy, agility, stability and injury risk. Speed and stability during turning maneuvers are important performance demands when evading predators or avoiding collisions/falls. We have investigated locomotor dynamics during turning maneuvers in the helmeted guinea fowl (Numida meleagris). To manipulate locomotor priorities evident during turning, we compared turning maneuvers on high versus low friction terrain. Turning maneuvers were executed in a 90-degree bent runway that was wide enough to allow variation in turn sharpness as a control strategy. We expected low friction terrain to cause a shift in priorities to minimize horizontal forces for slip avoidance, leading to slower speeds, shorter step lengths and a shallower turn angle (closer to bend-running) on slippery terrain. Overall, we found that guinea fowl used surprisingly similar turn strategies in both high and low friction terrains, opting for a relatively shallow turn angle in both conditions. This suggests peak load regulation is a priority in both conditions. Average running speeds were slower approaching turns compared to straight runs on both substrates. Low friction terrain increased the frequency of slips and falls, yet, despite this, led to relatively subtle changes in turn strategy compared to high friction terrain. Birds did exhibit a significant learning effect over repeated trials. With practice, birds learned to maintain higher speed during turns on the high friction substrate but continued to slow down in approaching the turn on slippery substrates. The findings suggest that guinea fowl shift their locomotor priorities with experience on varied terrain conditions. Further research is needed to understand how locomotor control is adjusted over different timescales and varied levels of experience in diverse environments.
