The Orang-Utan Bridge

The young male orang-utan is captured on camera crossing over a small tributary of the Kinabatangan using an orang-utan rope bridge.

KINABATANGAN: The orang-utan bridge project to reconnect isolated orang-utan populations within the Kinabatangan has obtained conclusive proof of success recently via photographic evidence. “Over the years we have received numerous local eye witness reports of the orang-utans using these rope bridges but this is the first time we have received photographic evidence which clearly shows a young male orang-utan using the first rope bridge we constructed in 2003 to cross over Resang river, a small tributary of Kinabatangan ,” stated primatologist, Dr. Isabelle Lackman, Co-Director of the Kinabatangan Orang-utan Conservation Project (KOCP) in a press statement.

The statement was jointly released by the Sabah Wildlife Department and French non-governmental organisation HUTAN yesterday. The photographs were obtained from a member of the local community, Ajirun Osman @ Aji who took the pictures February this year. According to Ajirun, the young male orang-utan spent about 20 minutes at the rope bridge tree before actually crossing over.

“It seemed like once he decided to cross, he did so very fast going over in about three minutes from the Pangi Forest Reserve into Lot 1 of the Kinabatangan Wildlife Sanctuary,” shared Ajirun. Dr. Lackman explained that in the past orang-utans would have used tall old growth forest as “natural bridges” over small rivers. However at present, the orang-utan’s no longer have this luxury since most trees have been logged. “Today the orang-utan is facing more human made obstacle’s such as illegal planting for oil palm all the way down to the river bank leaving no riparian reserve which are actually required by law under the Environment Protection Enactment of 2002 as well as the Water Resources Enactment of 1998,” said Dr. Lackman.

Furthermore, oil palm plantations also contribute to isolation of orang-utan populations when they build large drains (sizes of small rivers) to draw off excess water from the cultivation of palm oil. Unfortunately, all the great ape species which includes the orang-utans are unable to swim hence are further isolated within forest. To address such issues and to reconnect isolated populations, KOCP which was established by the Sabah Wildlife Department and the French Non Governmental Organisation (NGO) HUTAN in 1998, have built a total of six rope bridges.

“With support from various partners at American and European zoos, private foundations and the Borneo Conservation Trust of Japan 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,” said wildlife veterinarian Dr. Marc Ancrenaz who is also the Co-Director of KOCP.

Camera traps were also set up to capture pictures in the event of orang-utans using the rope bridges. However they either malfunctioned or were destroyed by macaques that used the rope bridges regularly. “Using rope bridges is a quick fix but eventually the most ideal solution would be to reconnect the forest and we are all working on this. And when I say ‘we’ I mean everyone from Governmental sector to environmental NGOs and crucially the palm oil industry as well,” added Dr. Ancrenaz.

Furthermore, genetic modelling carried out jointly by KOCP, SWD, Cardiff University and Danau Girang Field Centre 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. At present surveys carried out by SWD and KOCP shows that they are 1,000 orang-utans within protected and non-protected areas of the Lower Kinabatangan. Sabah has an estimated 11,000 orang-utans making it the stronghold for the Malaysian orang-utan population with 80 percent of the nation’s wild orang-utan population located here.

According to the Director of the SWD, Dr. Laurentius Ambu 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. “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 Clouded Leopards and many more,” said Dr. Laurentius.

Source New Sabah Times April 12, 2010