Meeting Abstract

S11.7  Friday, Jan. 7  Ecological and biomechanical insights into the origins of gliding in mammals BYRNES, G.*; SPENCE, A. J.; University of Cincinnati; Royal Veterinary College byrnesgt@ucmail.uc.edu

Gliding has evolved independently at least six times in mammals. Multiple untested hypotheses have been proposed to explain the origins of gliding. These include predator evasion, economical locomotion or foraging, control of landing forces, and habitat structure. Here we use a combination of comparative methods and ecological and biomechanical data collected from free-ranging animals to evaluate these hypotheses. Our comparative data suggest that the origins of gliding are often associated with shifts to low quality diets including leaves and plant exudates. Further, data from free-ranging colugos suggest that although gliding is not more energetically economical than moving through the canopy, it is much faster, allowing shorter transit times between foraging patches and therefore more time available to forage in a given patch. In addition to moving quickly, gliding mammals spend only a small fraction of their overall time budget engaged in locomotion, likely offsetting the high cost. Kinetic data for both take-off and landing suggest that selection on these behaviors could also have shaped the origins of gliding. Glides are initiated with high-velocity leaps, which are potentially effective for evading arboreal predators. Further, upon landing, the ability to control aerodynamic forces and reduce velocity prior to impact is likely key to extending leap or glide distance while reducing the likelihood of injury. It is unlikely that one of these hypotheses exclusively explains the origins of gliding, but by examining gliding in multiple groups of extant animals in ecological and biomechanical contexts, new insights into the origins of gliding can be gained.