Department of Biomedical Science, West Virginia School of Osteopathic Medicine, Lewisburg, 24901, USA.
Am J Phys Anthropol. 2011 May;145(1):43-54. doi: 10.1002/ajpa.21465. Epub 2011 Jan 4.
All primates regularly move within three-dimensional arboreal environments and must often climb, but little is known about the energetic costs of this critical activity. Limited previous work on the energetics of incline locomotion suggests that there may be differential selective pressures for large compared to small primates in choosing to exploit a complex arboreal environment. Necessary metabolic and gait data have never been collected to examine this possibility and biomechanical mechanisms that might explain size-based differences in the cost of arboreal movement. Energetics and kinematics were collected for five species of primate during climbing and horizontal locomotion. Subjects moved on a treadmill with a narrow vertical substrate and one with a narrow horizontal substrate at their maximum sustainable speed for 10–20 min while oxygen consumption was monitored. Data during climbing were compared to those during horizontal locomotion and across size. Results show that climbing energetic costs were similar to horizontal costs for small primates (<0.5 kg) but were nearly double for larger species. Spatio-temporal gait characteristics suggest that the relationship between the cost of locomotion and the rate of force production changes between the two locomotor modes. Thus, the main determinants of climbing costs are fundamentally different from those during horizontal locomotion. These new results combining spatiotemporal and energetic data confirm and expand on our previous argument (Hanna et al.: Science 320 (2008) 898) that similar costs of horizontal and vertical locomotion in small primates facilitated the successful occupation of a fine-branch arboreal milieu by the earliest primates.
所有灵长类动物经常在三维的树栖环境中移动，而且经常需要攀爬，但对于这种关键活动的能量消耗却知之甚少。先前关于倾斜运动能量学的有限研究表明，在选择利用复杂的树栖环境时，大型灵长类动物与小型灵长类动物相比，可能存在不同的选择压力。为了检验这种可能性，尚未收集必要的代谢和步态数据来研究可能解释在树栖运动成本方面的体型差异的生物力学机制。在攀爬和水平运动期间，为五种灵长类动物收集了能量学和运动学数据。研究对象在跑步机上以其最大可持续速度在狭窄的垂直和水平基质上运动 10-20 分钟，同时监测耗氧量。将攀爬期间的数据与水平运动期间的数据以及不同体型进行了比较。结果表明，对于小型灵长类动物（<0.5 公斤），攀爬的能量消耗与水平运动的能量消耗相似，但对于较大的物种，攀爬的能量消耗几乎是水平运动的两倍。时空步态特征表明，运动成本与力产生速率之间的关系在两种运动模式之间发生了变化。因此，攀爬成本的主要决定因素与水平运动的主要决定因素根本不同。这些结合时空和能量数据的新结果证实并扩展了我们之前的论点（Hanna 等人：《科学》320（2008 年）898），即小型灵长类动物水平和垂直运动的相似成本促进了最早的灵长类动物成功占领精细分支的树栖环境。
