Meeting Abstract
The physical characteristics of substrates that terrestrial animals move on can affect their locomotor performance and kinematics. Uneven surfaces are ubiquitous in nature and animals must frequently move across them, yet their effects on locomotion are not thoroughly understood. We studied how particle size and surface irregularity of uneven substrates made of large particles affect the locomotor performance and kinematics of the terrestrial generalist sprinter, the Northern Curly Tailed Lizard (Leiocephalus carinatus). To look for differences in locomotor performance, we compared seven substrates: a flat surface, three sizes of spherical balls ranging from 43 to 113 cm in diameter, and three sizes of natural rocks matched to the ball sizes. The flat substrate provided an even surface and served as the control, spherical balls provided a regular but uneven surface, and natural rock substrates provided an irregular and uneven running surface. As the size of the particles increases, the unevenness of the surface increases, which poses a challenge to animals running upon it. We expected that as unevenness increased, sprint performance would decrease. We also expected that as irregularity increased, sprint performance would further decrease because lizards would need to constantly adjust their stride while running, compared to the regular substrates. This work helps us understand how substrate unevenness and irregularity affects locomotor performance, which will have implications on microhabitat selection in nature, and how animals compensate for such challenges during locomotion.
