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Fieldwork Journal: Enchanted and Amused by Gibbons

From the Field posts

Mary Blair, assistant director for research and strategic planning at the Museum’s Center for Biodiversity and Conservation, is blogging from the field during her spring expedition to Vietnam. This is the last post for the 2014 expedition; read earlier posts here.

With our field surveys concluded, my research team is making a pit stop in Cat Tien National Park, the oldest national park in South Vietnam. We are here visiting the Dao Tien Rescue Center, a primate-focused rescue center working on best-practice protocols for reintroducing rescued lorises back into the wild.

Cat Tien National Park, Vietnam

Crocodile Lake in Cat Tien National Park

Photo by Mary Blair


Another reason I am excited to visit Cat Tien is to see up close some of my favorite primate cousins, the gibbons. This morning, we woke up to the sounds of a male yellow-cheeked crested gibbon (Nomascus gabriellae) and managed to run out and catch him on camera.

Yellow-cheeked crested gibbon 2014

A yellow-cheeked crested gibbon (Nomascus gabriellae) in Cat Tien National Park. The species is endangered, according to the International Union for the Conservation of Nature (IUCN). 

Photo by Mary Blair


The apes called gibbons are some of my favorite primates. Their vocalizations are eerily beautiful, an enchanting way to wake up in the morning. Gibbons are socially monogamous, living in male-female pairs, and each morning they defend their territory together, in a duet that typically lasts about 10 minutes. You can listen to a recording I made of part of a gibbon duet last year.

Gibbons are also fascinating to watch in the trees, because they are extremely well adapted for brachiating, or swinging, by their arms from branch to branch. The smallest of the apes, gibbons and all apes (including humans) have some anatomical characteristics in the shoulder that allow brachiation. 

Yellow-cheeked crested gibbon 2014

A yellow-cheeked crested gibbon (N. gabriellae)—singing and also demonstrating brachiation—in Cat Tien National Park

Photo by Thạch Mai Hoàng


Remember swinging between the ‘monkey bars’ in the playground? That’s brachiation. When you think about it though, perhaps monkey bars are not aptly named, since the true brachiators are apes, not monkeys. (There are only a couple of monkeys that can semi-brachiate: spider monkeys and muriquis.)

A side product of gibbons’ extreme adaptation to brachiation is that their arms are so long, and their legs so short, that they have a pretty funny way of walking bipedally (on two legs) on the ground. They swing their arms backwards and sway quite a bit side to side—but they get where they need to go, as you can see in this video I recorded at the Saigon Zoo.


We saw several other amazing creatures as well on our visit to Cat Tien, including this beautiful lizard that changes colors. I leave Vietnam with lots of data, hope for the future of lorises, and my ears full of gibbon music.

Calotes lizard

A changeable lizard (Calotes versicolor)—feeling blue in the face—in Cat Tien National Park


Working with partners around the globe, the Center for Biodiversity and Conservation (CBC) transforms knowledge—from diverse sources and perspectives—into conservation action. By developing professional, institutional, and community capacity for conservation, and convening and connecting key actors, the CBC fosters the ongoing discovery, awareness, and conservation of life on this planet.

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