Before they can be released to the wild, the orangutans have to learn how to survive in the forest – a process, that takes months, and can even take years!
After the orangutan arrives at their new home, they will take some time to settle in to the holding cages there, deep in the forest, and to recover from the transition, the orangutans begin to learn, step-by-step, how to survive in the forest. This can be a slow process taking several months, and even years in some cases. Many have to learn almost everything again, especially those captured from the wild as very young infants. Some, however, have not spent so long in captivity, and still seem to retain many of the skills they learned from their mothers.
One of the most important things for them to learn is which plants are edible, what constitutes food and where and when they can find it. Even then, with foods like the very thorny rotan palm, or termite nests, finding the food is not enough in itself, and they still have to learn how to process and eat it. Another essential survival skill is how to build a comfortable sleeping nest in the trees. Wild orangutans are adept at making comfortable springy platforms in the trees to sleep on, by bending and weaving leafy branches together. Some are also skilled at building a roof if they think its going to rain. Sleeping high up, off the ground is also the best way of avoiding ground dwelling predators and soil living parasites and pathogens.
Usually, an infant learns all of these skills from its mother during the first several years of its life. In the reintroduction center, however, the orangutans must be reminded or taught from scratch by SOCP field staff, or figure things out for themselves by experimenting and learning from other orangutans. To help them, SOCP staff will look for particular foods and eat (or pretend to eat …) them just as the orangutan’s mother would have done, showing them how it is done. Smaller and friendly individuals can also be taken out of the cages each morning and spend the day exploring for themselves in the forest, before returning to the cages at night to sleep. In the case of bigger or more dangerous orangutans that cannot be handled without anaesthesia, they must spend longer in the cages, and as many forest foods as as possible brought to them instead. When they are eventually released, at least they know what is food when they find it, and what to do with it.
A second chance of freedom!
When an orangutan is ready, it may be released directly from the cage area, or taken to a predetermined release site further into the forest. The exact site is chosen according to the characteristics of the orangutan in question. If highly sociable, it might be taken to an area where we know there are a number of other orangutans at the time. If aggressive, and potentially dangerous, it might be taken some kilometers away from the cage area and released there.
After their release, we follow the orangutans from dawn to dusk, recording their behaviour, range and tree use, diet and food intake, general activity and social interactions. These data can then be compared to both wild orangutans and other reintroduced orangutans ,to assess an individuals progress. Research and monitoring of this kind is essential to evaluate each orangutan’s progress and for the overall success of the reintroduction process. Using the information we obtain we are able to adapt and change procedures according to the needs.
The locations of both SOCP reintroduction sites were chosen very carefully. Extensive field surveys and feasibility studies were undertaken in a number of potential locations by Dr Peter Pratje, working for SOCP partner, the Frankfurt Zoological Society, in the late 1990’s. Bukit Tigapuluh National Park covers approximately 130,000ha of lowland rainforest making it one of the largest lowland rainforest conservation areas left in Sumatra! Being entirely lowland forest, with no large mountains above 700m asl, all 100% of the park is useable orangutan habitat.
Tha Jantho reintroduction center was established much more recently, in 2011. The site itself is within the Jantho Pine Forest Nature Reserve a protected area of lowland forest measuring 16,000 ha, but connected to forests stretching over 1 million ha. Parts of the edges of the reserve contain a Sumatran endemic pine tree species, hence the name, but the rest is rich tropical forest supporting a wealth of wildlife species.
Detailed suitability studies were carried at both sites prior to establishing the centers. At both, the food resources available for orangutans were extremely favourable. The type and density of orangutan food trees was found to be comparable to, if not better than it is in the well known Ketambe research station in the Leuser Ecosystem, where orangutan densities reach around 3 per square kilometre. Both sites were also remote, and hence not likely to be accessible to uninvited visitors, and far enough from human settlements and agriculture to minimise the risks of conflict between the released orangutans and local farmers. The existence of the reintroduction centers at both sites, and the presence of full time SOCP field staff also helps protect these important forests, keeping illegal loggers and poachers out. Both sites harbour valuable populations of Sumatran tigers and elephants, and a host of other rare and threatened Sumatran wildlife species.
Increasingly, SOCP has been involved with the capture and translocation of wild orangutans that have become isolated in areas being converted to oil palm plantations or other non-forest uses. Capture of wild orangutans is usually a difficult, risky and stressful operation, but unfortunately needed to be carried out more frequently. These orangutans are relocated to suitable nearby habitat or to one of the two reintroduction sites.
How we manage orangutans before they are released back to the safe forests
- Orangutan Threats – Why are we confiscating orangutans? Learn more about the threats to the Critically Endangered Sumatran Orangutan.
- Confiscation – Where do they get rescued from?
- Rehabilitation – Learn more about the process of health and management before an orangutan is released back to the wild.
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.