July 6, 2012
Parkour Tests Prove That For Orangutans – It Pays To Sway
redOrbit Staff & Wire Reports - Your Universe Online
According to a research presented at the Society for Experimental Biology's meeting in Salzburg, Austria on July 2, 2012, swaying through trees is the way to go if you're an orangutan.
Using human parkour athletes as stand-ins for orangutans, researchers measured the energy required to navigate a forest using different strategies. What they found is that it pays to stay up in the trees.
The findings explain why orangutans spend most of their lives in trees despite being much larger than other tree-living animals. The study also explains how these primates get by on their diet of mainly fruit, which does not provide a lot of energy.
Dr Lewis Halsey of the University of Roehampton, who led the study, said: "Energy expenditure could be a key constraint for orangutans — moving through trees could be energetically expensive."
The most efficient way to cross from one tree to another is usually to sway back and forth until you can reach the next tree. When trees are more strong and stiff, it´s more efficient to jump from tree to tree.
For heavy primates the tree must be quite stiff before jumping becomes the easier option. According to Halsey: "Heavier orangutans don't jump, and we may have an explanation why."
To compare the energy required to sway trees, climb trees, or jump from branch to branch, Halsey's team created obstacle courses simulating these activities. But instead of orangutans, the participants were parkour athletes, specially trained street gymnasts with good flexibility and spatial awareness. The athletes wore devices that recorded their oxygen consumption as they proceeded through the activities.
Halsey added: "Because primates are not easy to work with, estimates of energy expenditure have been very indirect. We have gone a step closer to understanding these costs by measuring energy expenditure in a model primate — the parkour athlete."
Image 2 (below): To learn about orangutan behavior, researchers used human parkour athletes as models for orangutans. They measured the energy required to navigate among trees in different ways, such as jumping between them. Credit: SRL Coward and LG Halsey