Bornean White-Bearded Gibbon

The Bornean white-bearded gibbon, also known as the Bornean agile gibbon or southern gibbon, is listed as Endangered by the IUCN. It is endemic to Indonesian southern Borneo (most of Central Kalimantan and eastern West Kalimantan) south of the Kapuas River and west of the Barito River. 

The center of the map is Borneo. The green is the range of the Bornean white-bearded gibbon - from Wikipedia. 

It has gray, tan or dark brown fur, a black face, hands and feet, white cheeks (beard) and eyebrows and no tail. 

They swing from branch to branch to get around, called brachiation, with arms 1.5 times longer than their legs, and can swing up to 49 feet in a single leap and as fast as 34 miles per hour. 

When they walk they hold their very long arms over their heads. They have a diet primarily of fruit (65%) and figs (23%), but will also eat leaves and insects. 

We saw only one gibbon, in Tanjung Puting NP in southern Central Kalimantan, at Camp Leakey near the Sekonyer River. Camp Leakey has a wood platform where rangers deposit food each day at 2:00 p.m. (usually bananas, but it can be other fruits, like durian). The primary partakers of the fruit are Borean orangutans, but one non-orangutan partaker, apparently on a regular basis, is a Bornean white-bearded gibbon. As tourists flock to the area near the feeding platform before the 2:00 p.m. feeding time, this gibbon, named "Bob", stands in a nearby tree waiting to swoop in and grab some fruit, with many tourists pointing and taking photos, including me. Our guide, Sam, told us that he usually swings to the platform surreptitiously, quickly grabs a handful of bananas and swings back into the trees. Then he usually comes back one more time for another grab. 

This gibbon was my favorite animal of the trip (pretty amazing considering we saw orangutans, Komodo dragons, water monitors and other types of monkeys and elephants). Bob got pretty close to us, waiting patiently in a tree. He wrapped his long arms back behind his back and around another tree. When he saw the rangers coming with bananas he stretched out his long arms and swung like tarzan from tree to tree until he was above the feeding stage. When the bananas were deposited he came quickly down a tree, using his long arms, hopped up on the platform, grabbed some bananas in his mouth and one hand, then walked awkwardly across the stage, then quickly back up another tree. Bob went high up into the trees and enjoyed his bananas, then came back several more times. One time he scurried quickly past orangutans, with his awkward walk, and back into the trees. People gasped loudly, including me, as Bob swung gracefully and quickly through the trees.