How Orangutans Traverse Treetops

A study in the Proceedings of the National Academy of Sciences reveals the secrets to how heavy orangutans travel through the trees without breaking branches and plummeting. Karen Hopkin reports

Illustration of a Bohr atom model spinning around the words Science Quickly with various science and medicine related icons around the text

Join Our Community of Science Lovers!


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


[The following is an exact transcript of this podcast.]

Why did the orangutan cross the forest canopy? Presumably, to reach some tasty fruit. But the better question might be: how did the orangutan cross the forest canopy. And according to a study published in the Proceedings of the National Academy of Sciences, the answer is something of a surprise.

Large apes that spend a lot of time in the treetops face a major challenge in getting to their food: how can they maneuver their bulk over those spindly little outermost branches, which hold all the best fruit? Scientists had predicted that the best way to navigate the canopy would be to swing underneath the branches, or to crawl over them carefully with knees and elbows flexed.

But orangutans have a different approach. They like to mix it up. Sometimes they move upright, sometimes horizontally with their limbs fully extended. They avoid repetitive motions, which could make their perches sway even more precariously. And they tend to grab on to more than one branch at a time—a third of the time they’ve got hold of more than four at once. Which is good because the apple might not fall far from the tree, but an orangutan doesn’t want to fall at all.

—Karen Hopkin

It’s Time to Stand Up for Science

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.

I’ve been a Scientific American subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.

If you subscribe to Scientific American, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.

In return, you get essential news, captivating podcasts, brilliant infographics, can't-miss newsletters, must-watch videos, challenging games, and the science world's best writing and reporting. You can even gift someone a subscription.

There has never been a more important time for us to stand up and show why science matters. I hope you’ll support us in that mission.

Thank you,

David M. Ewalt, Editor in Chief, Scientific American

Subscribe