Department of Integrative Biology, University of California, Berkeley, 3060 Valley Life Sciences Building, Berkeley, CA 94720-3140, USA.
J Exp Biol. 2011 Aug 15;214(Pt 16):2690-6. doi: 10.1242/jeb.052993.
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.
滑翔被认为是一种经济的运动形式。然而，关于自由滑翔的滑翔哺乳动物的攀爬和滑翔的数据很少。本研究采用了一种动物携带的三维加速度数据记录系统，来收集自由滑翔的马来飞狐（Galeopterus variegatus）的攀爬和滑翔的连续数据。我们将这些运动数据与水平或垂直移动的代谢成本的经验估计值结合起来，通过确定攀爬至足以滑翔给定距离的高度的代谢成本是否低于通过树冠水平移动相同距离的成本，来检验这一长期存在的假说。平均而言，飞狐会爬很短的距离来开始滑翔。然而，由于攀爬的能量成本很高，滑翔在移动给定的水平距离时比在树冠中以相同距离移动的动物所消耗的能量要多。此外，由于飞狐在其活动时间中只花费一小部分时间进行运动，因此高成本对其整体能量预算的影响很小。因此，滑翔起源的能量经济假说不成立。其他与生态相关的因素可能在飞狐和其他哺乳动物的滑翔起源中起了更大的作用。
