Suaq Balimbing Monitoring Station

There are three peat swamp forested areas that harbour 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. 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 in the Kluet Peat swamps was built in 1992 by Professor Carel van Schaik, then of Duke University, USA, looking for a new site to study orangutans that would provide detailed comparative data for comparison with other orangutan research sites such as the Ketambe station, located in the upper Alas River valley of the Leuser Ecosystem. During the following 6 years, two major PhD research projects were carried out at Suaq; the second of which was PanEco Conservation Director and SOCP Director Dr. Ian Singleton (1996-1998), then from the Durrell Institute of Conservation and Ecology (DICE), University of Kent, studying orangutan ranging behavior and seasonal movements.  As well as describing the first known cases of orangutans regularly making and using tools in the wild they also identified the Kluet peat swamps as harbouring exceptionally high orangutan densities, in fact the highest yet recorded in the world, reaching 8 per km2.  One unforeseen outcome of Ian’s work was the first real evidence for social organization among wild orangutans, likely more visible at Suaq than elsewhere due to the exceptionally high orangutan densities there.

In 1999, a deep seated separatist movement in Aceh escalated into a full blown armed conflict. Field work quickly became dangerous and the Suaq Balimbing camp was eventually abandoned, and was later destroyed completely.  In 2005, however, following the devastating tsunami of 2004 and a subsequent peace deal between the Aceh Separatists and the Indonesian Government, the station at Suaq Balimbing station was rebuilt and re-opened, with Professor van Schaik, now with the University of Zurich, and Dr. Singleton of the SOCP, managing the research and forest monitoring work under the YEL-SOCP umbrella. YEL was at the time also managing the Ketambe Research station as well.

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.

The Suaq Balimbing station within the Kluet peat swamps of the District of South Aceh has been operational since 1993, and managed by the SOCP since 2005.  As such Suaq has long been the site of a major ongoing research programme studying the orangutans and these unique peat swamp forests, with many new discoveries regarding the social structure and ranging behavior of orangutans having resulted from this work. Suaq remains the only forest in Indonesia where orangutans have regularly and routinely been observed making and using primitive tools, which they do on an almost daily basis.

YEL-SOCP currently has 7 permanent local field staff based at Suaq Balimbing to ensure data collection on the wild orangutan population is continuous, even if there are no additional visiting students.  Suaq is used as a research site by both Indonesian and international students. The site is also often visited by film crews and other media, especially those interested in the Suaq orangutan unique tool use culture. Suaq has also employed local villagers from the nearby villages almost continuously since 1993, except between 2001 and 2005, including some families who have had two generations working there.

Suaq Balimbing Boardwalk

Suaq boardwalk Wooden boardwalk built in early 2017
Suaq Monitoring Station Suaq basecamp
Suaq Station from above Suaq station from above
Suaq forests from above Suaq forest from above
Suaq forest
Suaq boardwalk New 2017 (l) and old (r) boardwalk in Suaq