“How pendulum-like are siamangs? energy exchange during brachiation”
Article first published online: 3 MAY 2011
Copyright © 2011 Wiley-Liss, Inc.
American Journal of Physical Anthropology
Volume 145, Issue 4, pages 581–591, August 2011
How to Cite
Michilsens, F., D'Août, K. and Aerts, P. (2011), “How pendulum-like are siamangs? energy exchange during brachiation”. Am. J. Phys. Anthropol., 145: 581–591. doi: 10.1002/ajpa.21539
- Issue published online: 8 JUL 2011
- Article first published online: 3 MAY 2011
- Manuscript Accepted: 21 MAR 2011
- Manuscript Received: 17 SEP 2010
- Research Foundation Flanders (FWO Belgium)
- Centre for Research and Conservation by the Flemish Government
- Symphalangus syndactylus;
- energy recovery;
Hylobatidae (gibbons and siamangs) are known for their brachiation skills. The comparison of brachiation with a pendulum is made several times in the literature, and the costs and benefits of being pendulum-like are well described. However, the amount of energy exchange during brachiation of gibbons has rarely been determined. In this study, the amount of energy recovery (ER) during brachiation is assessed for three siamangs in a seminatural environment. The animals were recorded by four cameras while voluntarily brachiating on three different setups. The effects of locomotion speed, brachiation type, and setup on ER as well as on the external mechanical work during brachiation are determined. It is hypothesized that the amount of ER decreases with an increasing setup complexity while the external mechanical work increases. Additionally, we expect that support arm kinematics will be adjusted according to spatial complexity in order to maintain high recovery percentages. Our results show that ER is mainly determined by brachiation speed. Regardless of type of brachiation or setup, brachiation is done with a lower ER when brachiating faster. Within our limited range of setup variation, the expected effect of increasing complexity is not found. Although there is significant variation in support arm joint angles, no clear relation with speed, brachiation type, or setup is observed. Am J Phys Anthropol, 2011. © 2011 Wiley-Liss, Inc.