Sumatran Orangutan

Fascinating facts about the Sumatran Orangutan

• Male Sumatran orangutans can reach 1.7 m in height and weigh up to 90 kg, making them the heaviest mammals that travel by tree. To cope with the flexibility of large branches they move slowly, maintaining long contact times and employing a wide range of locomotor postures. They even sway vertical supports back and forth, a behaviour that reduces the energetic cost of moving on compliant branches.
• By 2017 the wild population of Sumatran orangutans had fallen to roughly 13,846 individuals, highlighting their critical endangerment. In response, the World Wide Fund for Nature is running a captive-breeding programme aimed at increasing numbers while keeping the animals safe. This approach, however, carries the risk that prolonged captivity may erode natural behaviours needed for survival in the wild.
• Female Sumatran orangutans give birth about every 9.3 years, the longest interval recorded for any great ape, which slows population recovery. The species' average interbirth rate of 9.3 years is noted as the longest among its relatives. Infant orangutans remain in close contact with their mothers for up to three years before beginning to explore independently. Females can live 44-53 years, so only a few reproductive cycles occur in a lifetime.
• In 2024 a wild Sumatran orangutan named Rakus was seen chewing Fibraurea tinctoria leaves into a paste and applying it to a facial wound, after which the injury healed within weeks. This observation provides a rare example of self-medication in the species. Orangutans are also known to fashion tools such as sticks to extract termites or honey, showing the cognitive flexibility that underlies such behaviour.

Sources

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

• Wikipedia

At a glance

About the Sumatran Orangutan

In the lush, emerald canopies of Sumatra's ancient forests, the orangutan reigns as a majestic, solitary monarch, its deliberate, almost languid movements a testament to a life spent navigating the intricate, aerial highways of its native realm. With each deliberate swing of its powerful arms, it propels itself through the trees with a fluid, almost ethereal grace, as if defying the very forces of gravity that bind its terrestrial counterparts. As one of the most intelligent, and critically endangered, of all the great apes, the Sumatran orangutan embodies a profound, and precarious, beauty that inspires both wonder and sorrow.

Sumatran Orangutan photographed on Feravox

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