Before the Kinabatangan was logged, tall old growth trees provided “natural bridges” for orang-utans to cross over from the small rivers and tributaries.
Then came large scale oil palm plantations, some of which irresponsibly planted their crop all the way down to the river banks effectively splitting the habitat for orang-utans and other wildlife.
Through observational research and genetic studies we know that orang-utans that were previously moving between these rivers could no longer do so.
Then an idea came about to build an artificial bridge using ropes on the highest trees between the small rivers and our first orang-utan bridge was built over Sungai Resang in 2003. After all orang-utans in captivity use all sorts of rope bridges.
With support from various partners such as Cleveland Metroparks Zoo, Borneo Conservation Trust Japan, Shinning Hope Foundation and Danau Girang Field Centre (DGFC) we tried different designs using single ropes and more recently using old fire hoses from Japan intertwined together. This was to see if different designs would be used by the orang-utans.
But we had never been able to obtain photographic evidence of orang-utans using these bridges even when we used camera traps. Meanwhile other wildlife from squirrels to proboscis monkeys had been photographed using the bridges on numerous occasions. And we received reports of orang-utans using the bridges from fishermen but we never did we obtain conclusive proof via photographs nor researchers seeing this first hand.
Then in 2010, a local guide, Ajirun Osman @ Aji informed HUTAN-KOCP that he had taken pictures of an orang-utan using the first orang-utan bridge we had put up. It was also the simplest of all our orang-utan bridges and since then then they has been more photographic evidence of orang-utans using this bridge.
However, using rope bridges is a quick fix but eventually the most ideal solution would be to reconnect the forest and everyone from Governmental sector to environmental NGOs and crucially the palm oil industry have to be involved to make this a reality.
Furthermore, genetic modelling carried out jointly by HUTAN-KOCP, Sabah Wildlife Department (SWD), Cardiff University and DGFC has shown that unless action is taken urgently to reconnect these populations, most of the current isolated orang-utan populations within the Lower Kinabatangan will go extinct within our lifetime.
The Director of the SWD, Dr. Laurentius Ambu has stated that reconnecting forest via forest corridors or patches of forest is the next crucial step in addressing this issue for orang-utans as well as other wildlife in Sabah.
According to him, even though it will be an expensive and long process, reconnecting isolated populations which were originally linked together will ensure the long term survival of not only Sabah’s orang-utans but other unique species such as the Bornean pygmy elephants, the sunbears, the Sunda clouded leopards and many more.
Today, other NGOs and groups have began building orang-utan bridges in other parts of the Kinabatangan.