Currently, there are three peat swamp forested areas that harbor wild populations of the Critically Endangered Sumatran orangutan. These include the Kluet swamps, the Singkil swamps, and the now well known Tripa swamps, all of which are found on the west coast of Aceh Province, within the Leuser Ecosystem conservation area. Suaq Balimbing, an SOCP biodiversity monitoring station located in the Kluet swamps, is the only site in Sumatra where conservation biologists are currently monitoring orangutans in a peat swamp forest setting.
Relative to forests on mineral soils, peat swamp forests tend to have nutrient-poor soils with inadequate drainage, and also lack the huge emergent dipterocarp trees that are characteristic of many dryland tropical rainforests. Peat swamp forests also tend to be very wet and humid, and as such, trees rot and fall regularly, producing a dense tangle of smaller understory trees, tall grasses, and lianas. Even in the dry season, most of the forest floor is flooded to at least ankle or knee depth, whereas in the wet season it can reach chest height or even deeper in some places. This labyrinth of waterlogged natural growth makes human travel incredibly difficult. In fact, the earliest inhabitants of the Suaq field station were forced to develop a rudimentary boardwalk (one plank wide), which was built across the main part of the study area, so that they could more efficiently traverse the forest. This boardwalk is still a major necessity at Suaq to this day.
Since their underground peat layers are almost pure carbon, peat swamp forests are huge carbon stores. Furthermore, peat swamp forests store far greater amounts of carbon below ground, rather than above ground in trees and vegetation, making their preservation an important goal in the mitigation of global climate change.
The first monitoring camp at Suaq Balimbing was built in 1993 by Prof Carel van Schaik, then of Duke University. At the time, Carel was looking for a new site to study orangutans, one in which would hopefully provide detailed comparative material for the data already being collected at the long-term Ketambe monitoring station, located in the upper Alas River valley of the Leuser Ecosystem. From the very first reconnaissance visits, it was already clear that there was a sizeable orangutan population in Suaq; however, Carel was not initially keen on establishing a long-term project there, as following orangutans in such difficult terrain was always going to be a problem.
One day, during the initial trial year at Suaq, one of the field staff came back to the temporary basecamp and said that he had seen an orangutan making and using a small twig as a tool to get honey out of a bees nest in a tree. That was all Carel needed to hear, and he immediately began formulating plans to build a more permanent camp for research. Captive orangutans in zoos had long been famous for being expert tool makers and users, but before these pioneering observations, no one had reported seeing anything like this among wild orangutans. It thus appeared that the orangutans in Suaq had a unique local tradition or ‘culture’, and Carel was very anxious to explore this topic further.
In addition to detecting tool use ‘culture’, these early visits also established that Suaq had an exceptionally high density of orangutans, and in fact, these individual densities were much higher than any recorded from Borneo and also other sites in Sumatra. Indeed, whilst Suaq’s fetid peat swamp forest has been described as “Hell for people”, it was becoming clear that it was “Paradise for orangutans”. Nevertheless, the two unique characteristics of tool use and high individual densities are not necessarily mutually exclusive, and it is now hypothesized that the tool use observed in Suaq orangutans is socially learned, and that this local tradition is transmitted via their high levels of sociability.
Over the next 6 years, two major PhD research projects were carried out in Suaq. The first was undertaken by Dr. Elizabeth Fox (1994-1996), then from Duke University, who studied orangutan female mate choice, and the second was by PanEco’s Dr. Ian Singleton (1996-1998), then from the Durrell Institute of Conservation and Ecology (DICE), University of Kent, who studied orangutan ranging behavior and seasonal movements. During this period, Ian’s project was supported by the Durrell Wildlife Conservation Trust and Wenner-Gren Foundation, whilst both Carel and Beth were assisted by the Wildlife Conservation Society and the Leuser Management Unit. One unforeseen outcome of Ian’s work, was the first real evidence for social organization among wild orangutans, and this was likely more visible in Suaq than elsewhere, given its unusually high orangutan densities.
In 1999, a separatist conflict escalated in Aceh Province, and field work became increasingly more dangerous. As a result, the monitoring camp was eventually abandoned, and it was unfortunately later destroyed.
In 2005, following the devastating tsunami of 2004 and a subsequent peace deal between the Aceh Separatists and the Indonesian Government, Carel and Ian, both working closely with the Leuser International Foundation decided to rebuild and reopen the Suaq Balimbing station. Since the stations reopening in 2005, an additional eight PhD projects, four master’s projects, and four bachelor’s projects have been undertaken there. The SOCP-YEL currently maintains nine permanent local field staff members to ensure data collection on the wild orangutan population is continuous and without gaps, and Suaq is increasingly being visited by media and film crews, all hoping to document the unique tool use ‘culture’ of Suaq’s orangutans. Today, the station is primarily operated using funds from the PanEco Foundation, with additional support from the A.H. Schultz Foundation and the University of Zurich, where Carel is now head of the Anthropology Department.
Help us continue to be leaders in research of wild orangutans!
Support our work in wild orangutan conservation. Enable us to continue to protect and monitor wild orangutan populations for the future!
We have a number of students wanting to join our research efforts. Please contact us now. If your inquiry pertains to our research programs.
To counteract the explosive extinction of the Sumatran rainforest, the Orangutan Coffee Project supports coffee farmers in the highland of Gayo, Aceh province to manage their plantations in an ecological and sustainable way.
Special premiums from Orangutan Coffee trade reward both local coffee farmers and also support the Sumatran Orangutan Conservation Programme.