Intro
It is always “international” one thing or another day, but today, October 24th, holds a special place in my heart: International Gibbon Day. But what are gibbons, one might and indeed should ask. Gibbons are primates in the family Hylobatidae (derived from a word in Ancient Greek meaning “one who haunts the woods”). The term “Gibbon” actually encapsulates four genera and around 20 species of apes. Aside from being the cuddly-looking, long-armed, funny-walking spectacles that you see on YouTube videos, these primates are full of surprises.
Two gibbons in an oak tree ~ by Yi Yuanji
A singer in the forest
Let’s embark on an adventure…
Deep in a jungle of southern Thailand, a sound echoes against trees veiled with a thick mist. The noise at first sounds like a cry but becomes a melody as the mysterious source continues to sing out. Tracing this noise back to its source, we encounter a lone siamang gibbon. With each breath, the gibbon inflates its throat pouch and lets out the mighty sound which travels up to 1 km away. This particular siamang is communicating with his mate. Sensing movement nearby, the gibbon takes off, soaring through the trees. In fact, the highest recorded gibbon speed is a record-breaking 34 mph, which is around the speed of an eagle in flight. It’s an absolutley striking sight. This fluid movement through the trees is called called brachiation (derived from the Latin root “brachium”, meaning arm). Humans use brachiation too — although admittedly less elegantly. When we swing on aptly named “monkey” bars — though perhaps especially difficult monkey bars could be thought of as gibbon bars — we use our arms to move our bodies from place to place.
To locate the gibbon, who has since disappeared out of sight, we’ll use the clever technique of acoustic triangulation. Aha! There’s the furry silhouette again, now enjoying some delectable fruit. Upon closer examination, we see what makes this primate so unique. The gibbon has disproportionately long arms, 1.5 times longer than its legs. Part of the reason the siamang moves so gracefully through the canopy is due to its distinct wrist structure, which functions like a ball and socket joint. Between bites, we notice the 2.1.2.3/2.1.2.3 dental structure, a method to classify tooth types on the top and bottom of the mouth. Gazing into the eyes of the siamang, it’s hard not to feel a profound connection. Just how alike are we to these incredible creatures? The gibbon’s genome matches ours by approximately 96%. About 16.8 million years ago, the gibbons branched off from our lineage. Scientists theorize that a unique DNA element, the LAVA transposon that accelerates mutation rates, caused gibbons to diverge rapidly. Suddenly, more siamangs appear. Siamangs are social animals, living their lives in groups. The troop continues its journey through the forest, vanishing into the dewy morning.
The Decline and Fall of the Primate Empire *
Sadly, most gibbon species are endangered or critically endangered. The gibbon habitat faces fragmentation due to factors like plantations, forest fires, illegal logging, encroachment, and human development. Palm oil plantations, which have replaced large areas of rainforest in Indonesia and Malaysia, are a significant threat to gibbon habitats. Poaching and dealings in the illegal pet trade are also threats to gibbons.
Conclusions and Conservation
Gibbons. Two syllables that describe one remarkable primate. Choosing a favorite primate is like choosing a favorite ice cream: they’re all unique and wonderful (except, I imagine, for the alleged garlic flavored ice cream). However, the cuddly-looking, long-armed, funny-walking gibbons have in a special place in my heart. Despite the challenges they face, there’s hope for these stunning primates. Conservation initiatives have sprung up across Southeast Asia. For instance, the Gibbon Rehabilitation Center in Phuket, Thailand, is dedicated to rescuing previously captive gibbons and reintroducing them into the wild. The Kalaweit Project manages rehabilitation centers in Borneo and Sumatra. The IUCN Species Survival Commission Primate Specialist Group underscored the importance of gibbon conservation by declaring it the Year of the Gibbon, boosting global awareness through zoo events worldwide. These and other endeavors have played a pivotal role in maintaining gibbon populations in rainforests. This brief celebration is a poignant reminder of nature’s wonders and the remarkable lives of gibbons, beings so different, yet profoundly similar to us.
References
- https://wildambience.com/wildlife-sounds/white-handed-gibbon/
- https://www.sciencedirect.com/science/article/pii/S2351989422002475
- https://en.wikipedia.org/wiki/Gibbon