Orangutan Jungle Trek


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Sepilok Forest is a protected area of wild jungle along the Kinabatangan River in Malaysian Borneo. Each year only 300 people are allowed access to a restricted study site deep within the forest. 



This reserve – situated in the Lower Kinabatangan Wildlife Sanctuary – is utilized by Red Ape Encounters, HUTAN and other research organizations for orangutan observation. Our guide shared with me that entering this area without permission can result in two years of jail time or a fine of up to 20,000 Malaysian ringgits (at present, that’s over $6,000 U.S. dollars).



While on an ecotour to Borneo, our group was invited to visit this research site to observe the wild animals living in its perimeter – an experience that only researchers are normally granted. 



On a sweltering hot August morning, we left our rainforest lodge and cruised along the crocodile-infested waters of the Kinabatangan River – one of the longest rivers in Malaysia – to meet our expert naturalist guides in the reserve:

Then together we trekked through a protected mosaic of forest in search of wild, habituated red apes, discovering evidence of other wildlife along the way – such as sun bear claw marks on trees, hog footprints in soft mud, elephant dung and worm castles along the trail. Gibbons called to one another in the distance and exotic birds – like fruit-feasting hornbills – twittered in the trees.

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Although we were shaded from the intense sun by over 670 identified tree species (like the onion tree and strangler fig tree varieties), the air felt thick and humidity was high. Borneo’s rainforest is dense with foliage, and at some points it was difficult to spot elusive wildlife because of the thick canopy cover.

As we hiked through this natural jungle, sweat pooled beneath the brim of my hat, and I felt the nip of a giant leech looking for a blood meal on the back of my neck. Below, our guide Minchu displays one of these pesky Borneo rainforest inhabitants for a photo:



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After about thirty minutes of silent tracking through the vibrant green forest, a rustling from above indicated that we found what we came looking for – our red ape relatives. 





The two orangutans we observed in Sepilok Forest were thirty-year old Jennie and her five-year old, russet-haired son Molotus. Although Jennie is a habituated, wild orangutan and humans have been studying her since 1998, she is teaching Molotus ways to warn potential predators to keep their distance. This includes making kissing noises (meaning go away), breaking and tossing branches and even urinating down from the treetop.

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During our time watching the orangutans, we also observed Molotus placing leaves on top of his head, Jennie grooming Molotus, Jennie eating fruit and both mother and son navigating through the lush rainforest trees.

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Orangutan means person of the forest in Malay, and it’s easy to see why – humans and orangutans are 96.4% the same genetically and share 28 distinct physical characteristics. While red apes are usually loners in the wild, offspring will stay with their mothers for up to seven years, learning survival skills until independence is reached.

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Jennie Photo Credits: Ged Caddick



Orangutans are a transient species, moving through the thick, camouflaged forest on a daily basis. They are excellent climbers,  having an arm span of up to seven feet across, which gives them an incredible advantage in their life spent aloft. Human pressures – such as illegal hunting and deforestation – threaten the livelihood of this incredible species.

Borneo’s orangutans are currently listed by the IUCN Red List as an endangered species, so accurate data about these animals – what they eat, where they travel, their reproductive behaviors and so on – can help ensure effective conservation programs. 





In Sepilok Forest, over 15,000 hours of direct observation is providing insight into how these fascinating primates spend their time.

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Below, our guide Minchu reveals how researchers test tree species to determine the fruit, nesting and forest preferences of the orangutan.



Discover more insight into the orangutan species, HUTAN’s released data from their time spent in Sepilok Forest, and how manmade rope bridges might help orangutans navigate fragmented forest.



Want more? Get closer to more of Borneo’s wildlife and check out my other Nat Geo Wild blog posts on tree-dwelling pit vipers, saltwater crocodile breeding grounds, playful forest monkeys, a proboscis monkey harem and fierce monitor lizards.




Photo Credits: Jodi Kendall, captured on a Terra Incognita Ecotour