Bornean Orangutan

Fascinating facts about the Bornean Orangutan

• Male Bornean orangutans tip the scales at an average of 75 kg, but can range from 50 kg up to 100 kg and stretch 1.2-1.7 m down their arms, while females average 38.5 kg and measure 1-1.2 m. In captivity the record-breaker "Andy" hit 204 kg at age 13 in 1959. These dimensions make them the third-largest ape and the biggest fully arboreal ape on Earth.
• Bornean orangutans: they fashion leaf pads to wipe feces, hold spiny durian with a leaf "basket", swing a leafy branch as a bee-swatter, bundle branches into a rain-umbrella, scratch backs with a stick, and even launch a branch like a missile. This repertoire shows they can modify objects for specific tasks.
• Nest-building in Bornean orangutans is a sophisticated form of tool use. They weave leaves and branches into a sturdy platform, add a mattress of intertwined foliage, then layer shade, a waterproof roof, a "pillow" and a "blanket" for comfort. Young orangutans learn this by watching mothers, turning a simple sleep spot into a multi-component shelter that protects them from rain, highlighting the cultural transmission.
• Wild Bornean orangutans number about 104,700, but that is only roughly 14 % of their pre-industrial population from 10,000-year-ago baselines, with the steepest drop occurring in the last few decades. The collapse is driven by logging, palm-oil conversion and hunting, turning once-continuous forests into isolated patches and pushing the species toward extinction.
• Fire season in 2026 scorched 9,055 ha (22,000 ac) of Gunung Palung National Park, about half the size of Washington, D.C., forcing five individually tracked orangutans to flee mere meters from the flames. In a nearby oil-palm concession, a 657-ha protected block that once housed 50-60 orangutans was almost entirely burned, while a 2,330-ha block that supported 200 orangutans lost roughly half its area. These numbers illustrate how quickly fire can erase critical habitat and the individuals that depend on it.

Sources

Every fact above was checked against these pages, and kept only where one of them states it.

• Wikipedia
• Mongabay

At a glance

About the Bornean Orangutan

Deep within the lush, emerald canopies of Borneo's ancient forests, the majestic Bornean Orangutan reigns as a master of arboreal elegance, its deliberate, fluid movements a testament to a lifetime spent navigating the intricate network of branches and leaves that cradle its world. With eyes that gleam like burnished copper in the dappled light, this critically endangered ape surveys its domain with a quiet intelligence, its very existence a poignant reminder of the fragility and beauty of the natural world. As it swings effortlessly through the trees, its long, muscular arms propelling it with a slow, rhythmic grace, the Orangutan embodies the essence of a vanishing era, a symbol of the wild and untamed spirit that once thrived in these, our planet's most majestic ecosystems.

Bornean Orangutan photographed on Feravox

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