Orangutans in crisis

Bornean orangutans (Pongo pygmaeus) are classified as critically endangered on the IUCN Red List. A recent study published in Current Biology estimates that over 100,000 orangutans have been lost across Borneo between 1999 and 2015. The remaining orangutans exist in a number of geographically isolated groups known as “metapopulations,” and the study found that only 38 of the 64 Bornean metapopulations have more than 100 individuals — the threshold that scientists estimate is required for a viable population.

In Borneo, the orangutans’ natural forest habitat is disappearing at an alarming rate. Between 1973 and 2016, 30 percent of the island’s old-growth forest was converted to farmland for crops such as oil palm or lost as a result of forest fires — 195,000 square kilometers (75,300 square miles). “There is no land planning,” Preuschoft said, “only land grabbing.”

But the study also found large declines in orangutan numbers within the remaining forest, indicating that habitat loss is not the only threat. Hunting for bushmeat, the illegal pet trade and human-wildlife conflict over resources — plantation workers killing orangutans to protect their crops, for example — are all also important drivers of orangutan declines, according to the study’s lead author, Maria Voigt.

“The situation is critical,” said Voigt, a doctoral candidate at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. “What has been done in terms of conservation so far has not been enough to slow down or reverse the downwards trend.”

Every year, many orangutans are either confiscated by security forces or handed in by local people. The vast majority are juveniles under 7 years of age. Young orangutans are targeted for the illegal pet trade, and they are also often spared when their mothers are killed as a result of conflict with humans.

Orangutan orphans and their caretakers at the forest school. The caretakers must step in to teach the motherless orangutans the skills they need to live independently in the forest. Image courtesy of Four Paws.

In the wild, juvenile orangutans remain with their mothers for around nine years and learn from them the skills they need to survive. Scientists have analyzed the milk deposits on orangutan teeth and found that in some cases they can continue partially breastfeeding for up to eight years — more than any other mammal. Without their mothers to help them, confiscated young orangutans cannot be released back into the wild and must rely on human support — which is precisely the problem that Preuschoft’s forest school has set out to tackle.

However, rehabilitating orangutan orphans is not easy. You need to know about orangutan biology and ecology, their genetics and health, and the animals’ psychological and social needs, said Anne Russon, an expert in orangutan rehabilitation who’s not connected to Jejak Pulang or Four Paws.

“For a long time, rehabilitations were put together by do-gooders who saw a need that none of the professionals would pay attention to,” Russon, a primatologist and psychology professor from York University, Toronto, told Mongabay.

Barbara Harrison, an art historian by training, made the first attempts at orangutan rehabilitation during the 1960s in Sarawak, in Malaysian Borneo. Without the right knowledge, early efforts depended on trial and error. And, until the mid-1990s, rehabilitated orangutans that had been released back into the wild were not monitored, so it was impossible to evaluate the success of these introductions.

“Fortunately, for about the last 15 years, there has been a broader effort in orangutan research and conservation areas to … make sure it’s done properly,” Russon said.

A modern forest school

The team of 15 orangutan caretakers, two veterinarians and a biologist at the forest school are attempting to do just that. Preuschoft, the center’s operations director, has a background applying her training in psychology and biology to great apes, with five years’ experience working with captive chimpanzees in Austria and 10 years’ experience rehabilitating orangutans in Borneo.

“I realized that this is something that is very important — that people that do have science-based background knowledge and understanding of scientific methods basically get their hands dirty and try to improve the conditions of captive apes,” she said.

To create the forest school syllabus, Preuschoft has combined all her scientific training and great ape experience with research published by Russon on the requirements of rehabilitant-orangutans. Preuschoft is training a team of local people to act as orangutan caretakers, who move through the forest with the orphans and teach them the skills they need to survive. “Our slogan is to ‘orangutan-ize’ the humans, not humanize the orangutans,” she said.

For example, the Indonesian caretakers are learning to climb trees and recognize forest fruits. And, in a biodiversity hotspot like Borneo, there are an awful lot of fruits and plants to learn. “It’s really taking a long time before people become reasonably competent [enough] to recognize foods,” Preuschoft said. In fact, the amount of time it takes to train caretakers is currently the main constraint on the forest school’s growth.

Orangutan orphans Tegar and Gonda. The majority of orangutans the security forces confiscate are juveniles under 7 years of age. Image courtesy of Four Paws.

“What’s different for us compared to other programs is that I am very interested in the emotional maturation of orangutans,” Preuschoft said. That psychological aspect of their care is especially important for the orangutan orphans who have suffered the trauma of losing their mothers.

For caretakers, this means walking a fine line between offering emotional support to fill the void left by their mothers and not allowing the orphans to become overly reliant on them. To be successful in the wild, the orangutan orphans must be able to distinguish between their caretakers — “bonding partners,” as Preuschoft calls them — as well as familiar and unfamiliar people. Unlike some rehabilitation centers that rely on tourism to generate income, the funding from Four Paws allows Jejak Pulang to have a strict no-contact policy with anyone other than those working with the orangutans.

The plan is for the orangutans to stay in forest school until they have gained all the skills they need to survive independently. The youngest orphan, 11-month-old Gerhana, could spend up to eight years at the school. To maintain consistency for the orangutans, Preuschoft aims to keep turnover of caretakers to a minimum by providing training and ensuring the job stays interesting, pays well and instills a sense of pride in the team’s work.

In 20 years studying rehabilitant-orangutans, Russon has gathered many insights into orangutan biology and psychology. Without their mothers, these orphans must learn many things for themselves. “They come up with some very innovative kind of things,” she said. “You wonder how the hell they came up with them.”

Russon said she believes that orangutan intelligence is particularly apparent in rehabilitants because they share the same world as humans, so it is easier to understand their actions. “I really get a kick out of the rehabilitant-orangutans,” Russon said. “You go through the forest and live their lives with them.”

But teaching the orphaned orangutans the skills they need is only half the battle. As Voigt explained, finding a suitable release site can be a challenge. Reintroducing orangutans into areas with wild orangutans can lead to conflict with established populations, possible disease transmission, or competition for the limited habitat that’s available. In locations that are easily accessible to humans, the animals are likely to face pressure from hunting and agriculture. This means that rehabilitation centers need to find remote areas of suitable forest that do not already contain an orangutan population.

Preuschoft is all too aware of this challenge, and she is currently in negotiations with the Indonesian government for the exclusive use of just such a release site. However, she questions why no resident wild orangutan population currently occupies otherwise suitable habitat. “The reflexive answer would be hunting pressure,” she said. Preuschoft knows that, for the reintroductions to be successful, she and her team must work with local communities in the release area to gain their support.

Signe Preuschoft with an orangutan orphan at the forest school. Image courtesy of Four Paws.

Jejak Pulang has some experience with community relations after undertaking the same measures around their forest school. The center outsources the security work to an outside firm but takes on the responsibility of recruiting rangers to ensure that the security operation works hand in hand with the school’s community outreach program.

In the more remote area around the proposed release site, the local Dayak people still have a close relationship to the forest. “If we manage to talk with them early enough, then the elders who have that opinion are still alive and still powerful,” Preuschoft said. “We can try and find a path together with them from the traditional into modern times that doesn’t necessitate [destroying] everything.”

Jejak Pulang’s long-term goal is that the rehabilitated orangutans will act as an “umbrella species,” so that the area that is protected for them also provides important habitat for a host of other species.

Expensive measures

It takes a staff of 19 to care for Jejak Pulang’s eight current orphans, for as many as eight years. Rehabilitation programs are extremely expensive, and that burden has led some conservationists to question whether rehabilitation centers are the most effective way to spend scant funds from conservation donors.

“The question is, how much does it contribute to saving the species as a whole?” Voigt said. The few thousand orangutans rescued and rehabilitated during the 15-year period of her study’s research don’t seem like much compared to the more than 100,000 orangutans lost from the wild over the same period, she said.

“It is a conservation measure that only mitigates the symptoms and is not treating the cause of the problem,” Voigt said.

While Jejak Pulang’s dedicated team offers hope for eight orangutan orphans, the situation for their wild cousins looks bleak. Russon said she believes the root cause is the power of big multinational corporations, with no affiliation to the countries they operate in, financing unsustainable practices — like the rampant conversion of rainforest into oil palm plantations. “With the power structures in that form, we certainly don’t have a lot of hope that orangutans … are going to have habitat they can survive in,” she said.

In the meantime, confiscating illegally held orangutans plays an important part in the government’s measures to tackle wildlife crime. Once in captivity, the orangutans must be cared for in some way. Russon said she believes humans have a moral responsibility to give these animals the best life possible. For her, that means rehabilitating them when possible. “I understand it’s expensive,” she said, “but if we hadn’t mucked it up in the first place, we wouldn’t have to do these kind of things.”

In the case of Jejak Pulang, its funding comes from an animal welfare organization that would not otherwise spend on conservation, Preuschoft noted. She acknowledged that restorative conservation measures, like rehabilitation, are always more expensive and less preferable to conserving natural habitat and protecting wild populations to begin with. However, for Borneo’s orangutans, she believes it is already too late to rely on protecting wild populations.

“Of course we have to fight,” Preuschoft said. “But it feels more like you go down fighting than you could really win it.

“What’s the alternative? The alternative is that we allow orangutans to die out in freedom, and maybe survive for who knows how long in captivity.”

Orangutan caretaker Dona with 9-month-old Gonda at the Four Paws Orangutan Forest School. Image courtesy of Four Paws.

Banner image of orangutan orphans Tegar and Gonda courtesy of Four Paws.

Jim Tan is a Mongabay intern based in the U.K., currently in Sheffield. Find him on the web


Smith, T. M., Austin, C., Hinde, K., Vogel, E. R., & Arora, M. (2017). Cyclical nursing patterns in wild orangutans. Science Advances3(5), e1601517.

Voigt, M., Wich, S. A., Ancrenaz, M., Meijaard, E., Abram, N., Banes, G. L., … & Gaveau, D. (2018). Global demand for natural resources eliminated more than 100,000 Bornean orangutans. Current Biology28(5), 761-769.

Article published by John Cannon
, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

, , ,

Print button