title: Gliding saves time but not energy in Malayan colugos.
abstract: Gliding is thought to be an economical form of locomotion. However, few data on the climbing and gliding of free-ranging gliding mammals are available. This study employed an animal-borne three-dimensional acceleration data-logging system to collect continuous data on the climbing and gliding of free-ranging Malayan colugos, Galeopterus variegatus. We combined these movement data with empirical estimates of the metabolic costs to move horizontally or vertically to test this long-standing hypothesis by determining whether the metabolic cost to climb to sufficient height to glide a given distance was less than the cost to move an equivalent distance horizontally through the canopy. On average, colugos climb a short distance to initiate glides. However, due to the high energetic cost of climbing, gliding is more energetically costly to move a given horizontal distance than would be predicted for an animal travelling the same distance through the canopy. Furthermore, because colugos spend a small fraction of their time engaged in locomotor activity, the high costs have little effect on their overall energy budget. As a result, the energetic economy hypothesis for the origins of gliding is not supported. It is likely that other ecologically relevant factors have played a greater role in the origins of gliding in colugos and other mammals.
authors.affiliation: Department of Integrative Biology, University of California, Berkeley, 3060 Valley Life Sciences Building, Berkeley, CA 94720-3140, USA. byrnesgt@ucmail.uc.edu
authors.forename: Greg
authors.initials: G
authors.lastname: Byrnes
authors.forename: Thomas
authors.initials: T
authors.lastname: Libby
authors.forename: Norman T-L
authors.initials: NT
authors.lastname: Lim
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Spence
mesh_terms: D000054:Acceleration; D000818:Animals; D003624:Darkness; D004734:Energy Metabolism / Q000502:physiology*; D005426:Flight, Animal / Q000502:physiology*; D007900:Lemur / Q000502:physiology*; D008124:Locomotion / Q000502:physiology; D008296:Malaysia; D015203:Reproducibility of Results; D012399:Rotation; D013997:Time Factors