For the last eleven years, the Orang Utan Republik (first Education Initiative and now Foundation) has been working to address the Sumatran orangutan crisis, by providing local organizations on the island with grants, and supporting programs and projects that improve local people’s perceptions of, and attitudes towards, orangutans, and the importance of their forest home. The challenges OURF and other organizations face are both numerous and complex.


Orangutans are the only non-human great ape found in Asia, and were once widespread throughout most of the south east of the continent, and even as far as southern China. Today, two species of orangutan exist, on the island of Borneo, which is shared between Indonesia, Malaysia and Brunei-Darussalam, and the wholly Indonesian island of Sumatra. Previously considered endangered in Borneo (now critically endangered as of 2016), where most recent estimates put the population at around 55,000, OURF has focused its efforts on the critically endangered population in Sumatra, which numbers around 14,500 (as of 2016).

 Sumatra is an island in western Indonesia, and the sixth largest island in the world, with a population of around 45,000,000 people. Lying in the Pacific ‘Ring of Fire’, Sumatra has been both blessed and cursed by extreme volcanic activity, which has endowed the island with fertile land and abundant tropical forests. Home to 580 bird species and 201 mammal species, 9 of them endemic to the island (WWF, 2008), Sumatra is made up of dozens of ethnic groups, who speak 52 different languages between them. Although strong local cultures and customs still exist, Islam is today the dominant religion.

 Like most of Indonesia, Sumatra was once covered in tropical forests, and orangutans could be found throughout the island. Smaller, lighter colored and generally more social than the better known Bornean orangutan, today the Sumatran orangutan is found only in the island’s northern parts.  Legal and illegal logging, large scale forest conversion, mining and development brought about the extinction of southern populations and continue to fragment the remaining populations. Satellite imagery shows Sumatra has lost 48% of its natural forest cover since 1985 (WFF, 2008), and it is estimated that up to 800 orangutans are being lost every year as a result of habitat destruction and hunting. With a population of just a few thousand, if the current rate of decline continues, orangutans will be extinct as a genetically viable species in Sumatra within just 10 years.

 A population of 14,500 can often sound large, particularly when compared to the 400 wild Sumatran tigers still surviving, or the 700 or so mountain gorillas of central Africa. However, in context, the figure is frighteningly low. Orangutans have the longest birth interval of any land mammal, females giving birth to one young every 6-8 years, from the age of 15, and usually producing no more than 3-4 offspring in their lifetime.  With such a low birth rate, they are particularly vulnerable to hunting pressure or any kind of habitat destruction. Making the Sumatran orangutan crisis even more urgent is the fact that all of the orangutans in Sumatra are scattered throughout small patches of forest, all in the north of the island, all surrounded by human settlements and plantations, all isolated from neighboring populations, and all currently under serious threat of habitat conversion.


Of the 13 populations of Sumatran orangutans on the island, just 7 are considered viable, and just 3 populations contain over 1000 individuals (SOCAP Workshop Report, 2005). The biggest stronghold of the orangutan is the Leuser Ecosystem, an area of approximately 2.6 million hectares in northern Sumatra, which contains two major volcanoes, three lakes and nine major river systems, 4.2% of all known bird species, 2.6% of all known mammals and is the only place on earth where orangutans, tigers, elephants, rhino’s and clouded leopards can be found in one area (Robertson, 2002).  The ecosystem includes the 950,000 hectare Gunung Leuser National Park, which has been subjected to widespread legal and illegal logging, encroachment, palm oil conversion, forest fires and the Ladia Galaska road development, which has bisected the park in to two sections (EIA, 1999).

The swamp forests on the west coast of Aceh province, which harbor the highest densities of orangutans ever recorded and 30% of all remaining Sumatran orangutans, form part of the Leuser Ecosystem, and acted as a protective buffer zone for communities during the 2004 Asian tsunami, but have historically been cleared and drained.  Two thirds of the Tripa peat swamps forests have already been converted for palm oil plantations, and the area is, as of March 2012, at the forefront of a battle between environmentalists and the governor of the local province, Aceh, after he granted an Indonesian palm oil company permission to convert the area in to a plantation, despite a moratorium on forest conversion enacted by the national government in Jakarta last year, in spite of the Leuser Ecosystems protected status, the depth of the peat in the area, which makes conversion illegal, and despite the objections of local villagers. OURF’s partners in Sumatra have begun court proceedings in Aceh to gain clarifications on the legal status of the concession, but, in the meantime, the forests in and around the concession are being converted, and fires have been documented in the areas. Conservationists warned in 2005 that if plans to convert these areas went ahead, the orangutans of the Singkil, Kluet and Tripa peat swamps could be extinct within a little as 4 years (SOCAP Workshop Report, 2005). While efforts have so far been sufficient to ensure this hasn’t happened, much hinges on the outcome of the court proceedings, and the orangutans in this area remain severely threatened.

The most southerly populations of wild orangutans in Sumatra are found in the East Sarulla and West Batang Toru forest blocks of North Sumatra province. The 54,500 hectare East Sarulla block contains 250-300 orangutans, and approximately 600-800 remain in the 81,000 hectare West Batang Toru forest block. The steep, rugged terrain of these forests has largely protected the orangutans that inhabit them from incursions, which have so far been restricted to the more accessible lowland areas, but hunting by local people, for both sustenance and for the pet trade, and illegal logging is putting increasing pressure on these populations (SOCAP Workshop Report, 2005).

bukittigapuluhdeforestationtreehuggerFor the last few years, our partners the Sumatran Orangutan Conservation Program have run the world’s only Sumatran orangutan rehabilitation and release project, and have, to date, released over 130 orangutans in to the Bukit Tigapuluh landscape, a 320,000 hectare expanse of forest in Jambi and Riau provinces. This forest is extraordinarily rich in biodiversity, and hosts at least 80 mammal species, including around 30 tigers and 150 elephants, 193 species of bird, 98 species of fish and 4 species of reptile, and includes the 134,834 hectare Bukit Tigapuluh National Park. Despite a history of agricultural encroachment and logging, much of the park and greater landscape remains substantially wild. However, forest concessions to pulp and paper companies in recent years has seen massive deforestation, and recently revealed plans by these companies to convert further forest blocks on the border of the park in to plantations will directly threaten this biodiversity, and the orangutan release project (KKI Warsi, 2010).

 conference1Responding to these threats, in November 2006, OUREI organized a conference, workshop and summit, bringing all relevant stakeholders together to create a suitable education curriculum that addresses conflict between humans and orangutans in Sumatra. Working with our Indonesian partners (Sumatran Orangutan Conservation Program, Sumatran Orangutan Society, Orangutan Caring Club of North Sumatra, Fauna and Flora International, and Leuser International Foundation), we have delivered the curriculum to audiences near orangutan habitat in the provinces of North Sumatra and Aceh, explaining to local people both the importance of orangutans as a species, and the overwhelming importance of their forest home. In 2008, the program was expanded to include academic institutions and broadcast media, and the annual ‘Orangutan Caring Week’ continues to inspire young people in the Medan area of the island.

The challenges facing orangutans in Sumatra have never been greater, but with continued conservation efforts, and OURF’s expanding education program, we hope that Asia’s great orange ape and its forest home can survive.




EIA. (1999). The Final Cut. Environmental Investigation Agency, UK


Robertson, Y. (2002). Briefing document on road network through the Leuser Ecosystem. Wildlife Research Group, Cambridge University, UK.

Sumatran Orangutan Conservation Action Plan (2005). Workshop Report.

Wich S.A., Maijaard, E., Marshall, A.J., Husson, S., Ancrenaz, M., Lacy, R.C., Van Schaik, C.P., Sugardjito, J., Simorangkir, T., Traylor-Holzer, K., Doughty, M., Supriatna, J., Dennis, R., Gumal, M., Knott, C.D. & Singleton, I. (2008). Distribution and conservation status of the orangutan on Borneo and Sumatra. How many remain?. Oryx, vol 42, issue 3, pp. 329-339

WWF. (2008). Sumatra. WWF