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Orangutan refugees: weighing when to rescue the apes

  • Orangutans in Indonesia and Malaysia are increasingly threatened by agriculture, logging, fire, and conflict with people living nearby.
  • Some conservation groups have been moving orangutans out of stressed forest patches and into protected areas since at least the year 2000.
  • Critics of the practice worry that with little protected primary habitat remaining, translocation of orangutans to these areas may cause overcrowding, stressing ecosystems and provoking violence among the apes.
  • Instead, they advocate a renewed effort to protect intact forests and restore degraded forests as homes for displaced orangutans.

Foop,” went the hi-tech pressurized Spezialgeräte GmbH Telinject gun. And yet again “foop.”

The crack sniper from the Borneo Orangutan Survival Foundation (BOSF) lumbered about on the boggy forest floor, trying to line up a clear shot through the thick canopy foliage. He had already landed a couple of tranquilizer darts. Yet his quarry continued to leap from tree to tree while emitting loud “kiss squeaks,” the characteristic vocalization of a threatened orangutan.

Five BOSF team members scrambled below, trying to position a rope-net trampoline to catch the ape when the tranquilizers took hold. “Once the ketamine kicks in, he should fall in 10 to 15 minutes,” BOSF veterinarian Maryos Tandang whispered. In the end, it took three more hits before the 70-pound male fell headfirst into the well-positioned net.

BOSF veterinarian Maryos Tandang fills a tranquilizer syringe dart with ketamine while watching a treed orangutan during a translocation operation along the Mangkutup River in Central Kalimantan, Indonesian Borneo. Photo by Melati Kaye.
A BOSF sniper trains a tranquilizer-dart gun on a treed orangutan during a translocation operation along Borneo’s Mangkutup River. Photo by Melati Kaye.

Tandang rushed over to where the orangutan lay and pulled the darts out of his body. The vet checked the animal for wounds, took his temperature to check stress levels, injected a microchip so he could be identified if recaptured, and extracted a blood sample for genetic analysis later. Then the team packed the orangutan into a one-cubic-meter metal box for shipment.

Thus began another six-hour “translocation” rescue operation, one of many that BOSF executed from mid-December 2015 through January 2016 to shift animals away from the Mangkutup River in Central Kalimantan, Indonesia, and into the protected forests of Bagantung nine miles away.

Drought, illegal logging, and the catastrophic and prolonged fires late last year had so stressed the forest along the river corridor, BOSF president Jamartin Sihite told Mongabay by phone, that the 77 apes wound up “stuck in a small area.” This narrow patch of unburned forest was uncomfortably close to villagers’ vegetable gardens, a temptation for hungry orangutans that exposes them to retaliatory killing.

Doddy, a local speedboat driver contracted for the BOSF translocation, witnessed their plight first-hand. “The orangutans were on the banks waiting for us to pick them up and take them to safer place,” he recalled.

A shuttle out of the apocalypse. It was perhaps a hyperbolic claim but that is more or less how local media portrayed the operation. The orangutan rescues earned the non-profit BOSF front-page coverage in Indonesian regional and national dailies.

A BOSF rescue team sets up a rope net for a treed and sedated orangutan to fall into during a translocation operation along Borneo’s Mangkutup River. Photo by Melati Kaye.
BOSF rescue team members carry a sedated orangutan out of a burned-out forest patch during a translocation operation along Borneo’s Mangkutup river. Photo by Melati Kaye.

The sometimes literal airlifting of orangutans to safer ground has been a common conservation practice since at least the year 2000. Other NGO outfits, including International Animal Rescue (IAR) and the Sumatran Orangutan Society also run translocations. IAR rescued 11 orangutans in response to last year’s fires by translocating them to forest set aside for protection on an oil-palm company’s concession. In the Kinabatangan River system in Sabah, Malaysian Borneo, conservationists are testing a mix of translocation and wildlife-corridor building.

However, a growing number of conservationists and scientists, including field observer Beth Barrow at BOSF’s own Tuanan Research Center six miles south of the Mangkutup rescue site, are starting to see translocations for stressed orangutan populations as a last resort rather than a first response. In short, as a conservation tool that should be used sparingly.

BOSF rescue team members bring a female orangutan onto their translocation boat on Borneo’s Mangkutup river. After a check up, the team will place the animal in a metal cage for transfer to Bagantung forest nine miles away. Photo by Melati Kaye.
BOSF rescue team members check a four-year-old female orangutan for injuries before placing her in a metal cage for transfer and release into more suitable habitat. Photo by Melati Kaye.
BOSF rescue team members hold a baby orangutan while the team veterinarian checks the baby’s mother for injuries before transferring the pair to more suitable habitat nine miles away. Photo by Melati Kaye.

Research shows that orangutans, particularly flanged males, range in areas as big as 15 square miles to find food, and females forage in areas up to four square miles. Which means that orangutans may not be as “stranded” in stressed forests as many perceive if they can manage their own way to intact habitat. As solitary animals, wild dominant male orangutans do not socialize enough to learn habits that could help them adapt to new environments. And new arrivals can wind up overpopulating healthy translocation habitats and stressing animal communities already there.

Mongabay ventured with Barrow into the pre-dawn dark of Tuanan’s peat swamp forest to stalk Nico, a large, older flanged orangutan who is the dominant male in the area.

“The two jackfruit trees near camp are his property,” Barrow pointed out. She and her assistant marked the base of the tree holding Nico’s latest nest with orange plastic tape. They have tracked him for half a year now and estimate that he travels a mile or two per day.

If Nico were to be uprooted and abruptly translocated to a different environment, he likely would be too standoffish to learn from his new neighbors where to find food in his new home.

Habitat conservation, rather than heroic individual rescues, are more beneficial in the long run for the orangutans’ survival prospects as a species, primatologist Carel van Schaik, director of the University of Zürich’s Anthropological Institute and Museum, told Mongabay by phone.

“But people want to spend money on saving souls, rather than setting aside forest,” van Schaik lamented, which he said sets up a false “ransom situation” in which the only options appear to be either letting threatened populations die or shipping them off to habitat already occupied by wild orangutans.

In the latter situation, even socialized females and unflanged males capable of learning the cultural adaptations they need to survive in translocation habitats can wind up being persecuted by the original orangutan inhabitants. Van Schaik’s graduate students have recorded instances of established females ganging up with males to kill newly arrived females in the Tuanan area.

A better option, van Schaik suggested, may be to shift displaced populations into restored habitats where orangutans have previously been hunted into extinction.

This is a tall order. Recent research shows that only half of Borneo still has forest cover. In the last 40 years, the island has lost nearly 65,000 square miles of tropical forest, four times the land area of Switzerland, according to an analysis of satellite data led by the Center for International Forestry Research based in Bogor, Indonesia.

And in the wake of the deforestation and destruction of their native habitat, only around 60,000 orangutans remain worldwide, according to the most recent count from 2008. The apes only survive on two Southeast Asian islands, Borneo and Sumatra.

Even in the immediate neighborhood of Borneo’s protected Bagantung forests, where BOSF is relocating the 77 rescued orangutans to, much of the forest is gone. The once-lush swamp forest of central Borneo was drained to create paddy fields for an ill-fated “mega-rice” project of the former dictator Suharto, aimed at making Indonesia self-sufficient in food production.

A “super El Nino” in 1997 further doomed the mega-rice scheme by drying out thousands of hectares of flammable peatland that went up in smoke. The disaster spurred BOSF into existence and brought in enough international funding for the group to airlift orangutans out of the area by helicopter. It moved some animals to locally protected forests and others as far as East Kalimantan, a whole time zone away.

Ironically, during the drought and disastrous fires in 2015, the disused irrigation canals of the failed mega-rice venture allowed BOSF to make far more cost-effective rescues by speedboat rather than by air.

Still, the head of BOSF’s Mangkutup translocation team, Pak Odom, defended the group’s current translocation approach. Letting displaced animals make their own way within stressed forests might seem logical, he said, but it forces the animals into competitive contact with their deadliest predator: humans.

To illustrate the danger, he recalled coming upon an orangutan corpse while on a rescue mission.

“We found him in a villager’s vegetable garden,” Odom related. “He was shot in the left chest and his back was slashed open.”

As per BOSF protocol, the team double-wrapped the body in blue plastic body bags and transferred it to their Palangkaraya, Central Kalimantan clinic — an hour-long boatride and a two-hour car ride away — where an autopsy was performed to confirm the details of his death.

Such casualties are not only heart wrenching, but also seriously damage the species’ prospects of survival. Orangutans only reproduce every seven to eight years so untimely deaths can significantly impede their ability to maintain a stable population size.

Barrow, at the Tuanan research station, agrees that that such conflicts will only increase. “Fires mean that there are now more orangutans in a smaller area. This will lead to starvation in the next year and more conflict as orangutans raid vegetable gardens and plantations,” she said.

A flanged male orangutan peers out of a metal cage during a translocation operation along Borneo’s Mangkutup river. Photo by Melati Kaye.

With orangutan translocations, there are no simple answers, Barrow said. Rather, the problem of displaced animals calls for a case-by-case solution. She listed the relevant determinants: how densely packed the orangutans are and how different the food sources are in their destination habitat versus the potential for deadly human-orangutan conflicts if they are left in situ.

The journey from the burned out Mangkutup river corridor to BOSF’s Bagantung forest relocation site takes six to ten hours. For such a long trip, BOSF standard operating procedure instructs translocation teams to surround a captured, still-tranquilized animal with leaves inside its metal transport box. They do this to cool the box but also so that “when the orangutan wakes up, it thinks it is in a nest,” explained Fit, the relocation team’s second veterinarian, who is charged with escorting the orangutans to their new habitat after Tandang and his team rescue them.

Illegally harvested logs float down both sides of a river early in the BOSF rescue team’s journey with three translocated orangutans from Borneo’s Mangkutup River to Bagantung forest. Photo by Melati Kaye.
Pandan palms curtain the river path later in the BOSF rescue team’s journey with three translocated orangutans. Photo by Melati Kaye.

Inside the box are also small tropical bananas “in case the orangutans get hungry,” Fit explained.

“But they rarely eat them,” she confided. “Wild orangutans don’t eat bananas. Only in people’s gardens if they are really starving. But they do like oil-palm fruit.”

With three boxed orangutans on board, the boat was too heavy. The engine broke down, forcing the team to ask another BOSF team that was heading up-canal to plant trees to tow them to an improvised release site.

“Too bad, the place the orangutans were going is so beautiful: a thick forest with a variety of species and fruits,” said Fit. It sounded like a heaven for orangutans. Instead, as a result of a mundane logistical snafu, the team had to change the release site to a closer station with a denser population of resident wild orangutans.

Like a bizarre Japanese anime sequence, the two-boat regatta chugged its way through the burned out landscape.

Still, the translocated passengers seemed unperturbed. As soon as the boat ported, and the metal doors on the boxes were lifted, the apes ran out and jumped into trees. One female scampered far aloft, then descended from a tree for a drink. The 70-pound male turned and looked back, leaning on a branch, surveying the scene and letting loose a long stream of urine. No way of telling whether it was out of anxiety at his new prospects or relief at getting out of the alien speedboat.

When BOSF’s Bagantung forest monitoring team ran their monthly observations, they reported that only a couple of orangutans remained close to the release site. Field technicians spotted a few others spread out into the forest that has grown over one of the old ‘mega-rice’ blocks.

A BOSF rescue team releases an orangutan in Borneo’s Bagantung forest. Photo by Melati Kaye.
A translocated flanged male orangutan in his new home in Borneo’s Bagantung forest. Photo by Melati Kaye.