Bleak For The Bornean Orangutan; Contiguous Forest Corridor Needed

An aerial view of a patchwork of forests inter-spaced in an oil palm-dominated landscape in Lower Kinabatangan, Sabah.

SPECIAL REPORT: Sabah’s Lower Kinabatangan has lost almost a third of its orangutan population in the last 16 years, following continued loss of forests outside of protected areas and further fragmentation of their habitat that is home to other wildlife, including the Borneo pygmy elephant and the proboscis monkey.

These forests outside protected areas – including privately owned and state lands – are largely composed of swamp areas that are increasingly becoming threatened in Borneo and which have poor or no economic value for oil palm due to daily or seasonal flooding events.

Long term monitoring has revealed that the decline of orangutan has not stopped in the Lower Kinabatangan, despite this being identified as a high priority area for the primate in Sabah’s Orangutan Action Plan. It is critical to both address the future of these forests outside of protected areas and to recreate contiguous forest corridors.


The future is bleak for the Bornean orangutan, which last year moved to IUCN’s Critically Endangered category with numbers dropping from 4,000 individuals in the 1960s to 1,125 in 2001 to less than 800 today in the Lower Kinabatangan. A study published this month in Scientific Reports indicates Sabah’s overall orangutan population has dropped by 20 per cent since the last comprehensive survey in the early 2000s, which had placed their number at 11,000 individuals.

Dr Marc Ancrenaz, Borneo Futures co-founder, said habitat fragmentation in Lower Kinabatangan remains a major issue with 11,000 hectares of forests outside protected areas lost in under a decade up to 2014, and over 20,000 hectares on alienated and state lands at risk of being converted for agriculture, primarily oil palm, further fragmenting the orangutan population and accelerating its decline.

Elaborating the value of forests outside of protected areas for biodiversity, Ancrenaz said a habitat suitability model developed for 13 mammal species in the Lower Kinabatangan revealed that 91 per cent of these non-protected forests were a good home for orangutan.

An orangutan feeding on bark in a small forest patch in the Lower Kinabatangan.

“Despite their degraded status in the Lower Kinabatangan, these are High Conservation Value forests and are key to supporting wildlife but further fragmentation would jeopardize the viability of animal populations.

“We need to recreate a contiguous forest corridor of about 52,000 hectares in the floodplain. One way of starting the process would be to address the future of forests that are not part of the Lower Kinabatangan Wildlife Sanctuary and forest reserves,” he said.

However, acquiring privately owned lands and habitat restoration are both costly in a landscape that is about 82 per cent covered with oil palm, a crop that is important to Sabah’s economy and a trade imperative for Malaysia.

“The orangutan population in Lower Kinabatangan needs to be reconnected if Sabah wants to ensure its long-term viability. In a study on orangutan throughout Borneo, it was discovered that forest patches inhabited by this primate are the smallest in Sabah compared to other states and in Borneo and the distance between patches is the longest.

An island of forest completely isolated in an extensive oil palm landscape.

“This latest information shows that efforts must be made to secure habitats in forests outside the current protected areas to ensure that the population of orangutan in this region does not further drop,” said Ancrenaz, who has spent almost 20 years in the Lower Kinabatangan.

Hunting, poaching and over exploitation of forests were historical threats that kick started the decline of the species. However, the species is facing new risks today, such as habitat fragmentation, emerging diseases and conflicts with domestic animals or snares that are set up to catch wild boars but also catch orangutan when they walk on the ground.

Ancrenaz had recently undertaken a case study named “Addressing the Impact of Large-Scale Oil Palm Plantations on Orangutan Conservation in Borneo: A Spatial, Legal and Political Economy Analysis” for the Environment and Development project with Ridge to Reef co-director Holly Jonas and Living Landscape Alliance founder and co-director Dr Nicola K Abram. The study was funded by Arcus Foundation.

The case study produced an analysis of the geographical overlap between primate’s Bornean habitat and areas demarcated for large scale oil palm development, as well as the extent to which their habitat lies within existing protected areas in Sabah, Sarawak and Indonesia’s Kalimantan.

An analysis was also done on how legal frameworks and political economies interact with the oil palm industry and orangutan conservation in Borneo.