Colugos and Orang Utans in the Bornean Rainforest

A night safari reveals alien-looking gliding mammals

2 JULY 2014,
Gehan de Silva Wijeyeratne. Sepilok
Gehan de Silva Wijeyeratne. Sepilok

Tall forest giants reached for the stars whose light grew in intensity as darkness descended upon a primeval landscape. The rainforests in South-East Asia had evolved over a hundred million years ago and this was the nearest I could time-travel into the past. I was in search of a zoological mystery. I was in search of the Colugo.

To be more specific I was after a Malayan Colugo, which with the Philippine Colugo is one of two species to have one of 28 zoological orders of animals all to themselves. Consider that all of the whale and dolphins in the world belong to one zoological order and all of the carnivores (from bears to wolves to lions) belong to another; so for just two species to have a zoological order to themselves is quite special. The Malayan Colugo is not rare. It even occurs in the tiny island state of Singapore. Its range spreads from Myanmar, Indochina, the Malay Peninsula to Borneo and Java. Its distribution points to a time when during periods of glaciations the levels of shallow seas around the island of Borneo had fallen so that these South-East Asian islands and the mainland were connected as one contiguous block of land.

The Colugos are not the only mammals living in the tree tops which are able to glide. Flying squirrels on the continents of America and Eurasia, the scaly-tailed squirrels of Africa and the marsupial gliders of Australia and New Guinea have evolved flaps of skin joining their limbs which enable them to glide. But the Colugos are different. They are the largest of the gliding mammals with a wingspan of 70 cm. Furthermore their ‘wings’ extend right to the tips of the toes and fingers and unusually across all of the tail as well. Thus, of all the gliding mammals, they are the best designed for an aerial life. I was also fascinated by their look, camouflage and body form, which reminded me of the first glimpse of the alien hunter in the film ‘Predator’ starring Arnold Schwarzenegger.

I was on the island of Borneo: a place so evocative of the rainforest. Sadly though, much of it has been lost in the last century to plantations; more recently to oil palm. The cicadas struck an ear splitting chorus and the last of the diurnal forest birds had fallen silent. I was at Sepilok, a forest reserve better known for its rehabilitation program for Orang Utans. In the morning, visitors throng the viewing areas for the feeding of the Orang Utans that are under rehabilitation. The centre also runs night walks using the same boardwalk used by daytime visitors to take you into the forest. My guide suggested we enter the forest. I countered that we stay on the outer edge and scan the tall trees. In Sri Lanka I was familiar with watching Giant Flying Squirrels and had noticed how they glide from one tall Albizia tree to another in degraded forests. I had a hunch that a Colugo may do so from one of the tall Dipterocarp trees that fringed the forest.

The torch beam sliced through the darkness and quivered and danced along the boles of the forest giants as my guide searched for a Colugo. It did not take long before he spotted one. No, there were two. The one lower down shuffled to the one a few feet higher up and the two interacted. Then we spotted a third. They looked like animals from another world. The strangeness arises from the gliding membrane which is stretched over the tail and cocoons the animal in what seems like a tent-like structure. The guide even saw a flying squirrel on the same tree. The torchlight used by the guide was white light which disturbs mammals (torches with a red filter are best). Conscious of the disturbance, I suggested we move on and listen out for owls.

We stood in a clearing and listened. Above me the tree canopies seemed like an interlocking pattern of lacework lit by a faint moon. It was not long before we heard an owl, although I was not sure what species it was; it did not matter but to feel so alone in the rainforest amidst the cacophony of insects and amphibians was special. The forest at night is an aural landscape. The squeals, squawks and barks of amphibians pulse through the forest like a river of sound.

The following morning I was back at Sepilok with my family to view the Orang Utans. My daughters Maya and Amali clicked away with their cameras amidst the oohs and aahs of visitors when a mother Orang Utan appeared with a baby. A dozen languages were spoken by the destructive apes on boardwalks whose appetite for oil palm is threatening the red ape. Africa is recognised as the cradle of humans. However the Orang Utans may be part of a surprising Asian connection to early humans. One theory holds that a migration of apes took place between Asia and Africa about 20 million years ago. The Orang Utans and the gibbons in Asia are descendants of this migration. Some of the apes migrated back to Africa to evolve into the humans and the African apes that remain today. On the feeding platform my guide from last night held some fruit in his hand and a young Orang Utan draped its hand over his shoulder and snuggled up to him. Twenty million years later, on a crowded planet, the ancient lineage and emotional bond between the two descendants are still clear.

Useful Wildlife Books

Baker, N. & Lim, K. (2008). Wild Animals of Singapore. A photographic guide to the Mammals, Reptiles, Amphibians and Freshwater Fishes. Vertebrate Study Group, Nature Society (Singapore). 180 Pages.
Dawkins, R. (2004). The ancestor’s tale. A pilgrimage to the Dawn of Life. Weidenfeld and Nicolson. 528 Pages.
Phillips, Q. & Phillips, K. (2011). Phillipps’ Field Guide to the Birds of Borneo. Second edition. John Beaufoy Publishing: UK. 372 Pages.
MacKinnon, J & Phillipps, K. (1993). A Field Guide to the Birds of Borneo, Sumatra, Java and Bali. Oxford University Press Inc., New York, United States. Illustrations by Karen Phillipps. 459 Pages.
Payne, J., Francis, C.M. & Phillipps, K. (1985). A Field Guide to the Mammals of Borneo. The Sabah Society, Kota Kinabalu, Sabah. 332 Pages.
Payne, J., & Prudente, C. (2010). Wild Sabah. The magnificent wildlife and rainforests of Malaysian Borneo. John Beaufoy Publishing: Oxford. 208 Pages.

Travel Logistics

I emailed a few of the tour operators listed in the travel guides by Rough Guides and Lonely Planet. I found Jessie Chin of Sepilok Tropical Wildlife Adventure the most responsive to tailoring a 5 day family wildlife tour. info@stwadventure.com, www.stwadventure.com.
Hard core birders and wildlife photographers may also like to contact some of the specialist nature tour operators some of whom attend the international wildlife travel fairs such as the British Bird Watching Fair.