Relocation of Wild Orangutans Often Threatens Their Survival: Study

Authorities in Indonesia and Malaysia frequently relocate wild orangutans, which can leave them hungry, lost and in conflict with established residents. Many displaced orangutans make the journey back home, sometimes over 60 miles to the areas where they were raised.

According to a new study, there are several reasons for orangutan relocation: If they are found to be feeding on or damaging crops or are presumed likely to do so; deemed a risk to humans or property; in the path of human development; at risk from forest fires or human attacks; living in unsuitable habitats; or believed to be malnourished.

“While wild-to-wild translocations may remove individuals from situations where their lives are in immediate danger from humans, they have limited long-term success in mitigating human-wildlife conflicts and, in many cases, also have negative impacts on post-release survival and welfare of released individuals and on species conservation,” the authors of the study wrote. “Unintended outcomes of wild-wild translocations undertaken to ameliorate conflicts include injury or death of individual animals during capture, translocation or release, and released individuals being killed by conspecifics or humans.”

The research team investigated “wild-to-wild” translocations of orangutans in Indonesia between 2005 and 2022, mostly relying on public data and consultation with practitioners.

They found that almost one-third of the orangutans returned to the original site of their capture, reported The Guardian. Sometimes mothers were separated from their infants, which threatens the survival of younger orangutans, who can spend as long as nine years being dependent.

“At least 988 wild orangutans were captured for translocation during the study period, including many reproductively valuable resident females and adult males removed from unprotected fragmented forests and forest patches,” the authors wrote.

The researchers said that 81.7 percent of the orangutans were healthy when they were captured, which raises concerns as to whether many of the translocations were even necessary.

“Some of these animals are really old. In one instance, a 60-year-old male was moved. To you and me, that’s like if someone kidnaps your grandpa and knocks him out, blindfolds him, drives him miles away from his neighbourhood, and then drops him off in some city he’s never seen, where the people are unhappy to see him and might be aggressive,” said lead author of the study Julie Sherman, director of Wildlife Impact.

All three orangutan species — Sumatran, Bornean and Tapanuli — are listed as critically endangered by the International Union for Conservation of Nature. Once widespread throughout southeast Asia, our closest animal relatives are now only found on Sumatra and Borneo, where the last of their fragmented forest homes remain.

Conservationists are trying to come up with the most effective protection measures for the endangered great apes in the face of fears of the expansion of palm oil plantations in the region.

All three species have experienced drastic declines in recent years. With roughly 105,000 remaining, the Bornean orangutan is the most common. Approximately 14,000 Sumantran orangutans survive, while there are only 800 Tapanuli orangutans in an isolated area of Sumatra, making them the world’s most endangered great ape.

For the study, the researchers reviewed government reports, news stories and scientific research. They warned that relocating orangutans — often far from their home territories — disrupts their social structure.

Over three-quarters of orangutans are living outside of protected areas, but are able to do well in areas of fragmented forest, on croplands and plantations, which can put them into unexpected contact with humans.

Co-author of the study Serge Wich, a biology professor at Liverpool John Moores University, said more effort is needed to encourage people who live on the edges of forested areas to coexist with orangutans rather than uprooting them and transporting them to unfamiliar places.

“It is really key that we work with local communities and companies to find a solution for this. This is not a sustainable way for the future. We can’t capture all the animals that are on the edge of the forest. There’s going to be more and more forest edges, unfortunately, as development continues and roads come in. We need to find a way to keep animals where they are and manage them in a matrix of forest, oil palm and community gardens. Otherwise, we’ll end up with very small populations in bits of forests,” Wich said.

Between moving adult orangutans — the females of which only give birth about once a decade — and killing them, researchers warn their populations could plummet.

“We [need to] make it feasible for people and orangutans to coexist alongside each other, akin to how it is with foxes in the UK,” Sherman said. “You could kill them all, move them all. Or, find a way to coexist with them – because they’re happy using the spaces that we are in.”