Their black eyes peer from the slats of wooden cages, hundreds of orangutans orphaned after their mothers were shot or hacked to death for straying out of Indonesia's rapidly disappearing forests in search of food.
No one wants to get them back into the wild as much as Birute Mary Galdikas, who has devoted a lifetime to studying the great red apes, now on the verge of extinction. And for the first time in years, there is a glimmer of hope on the horizon, thanks to a Hong Kong-based development company's plans to protect a 91,000-hectare (224,866-acre) peatland forest along Tanjung Puting National Park's eastern edge.
"The problem has been finding a safe place to release them," said the 64-year-old scientist. "Many are ready to go right now."
A half-century ago, more than three-quarters of Indonesia, a sprawling archipelagic nation spanning the width of the United States, was blanketed in plush tropical rainforest. But in the rush to supply the world with pulp, paper and, more recently palm oil — used in everything from lipstick and soap to "clean-burning" fuel — half those trees have been cleared.
It is here, in scattered, largely degraded forests, that almost all the world's 50,000 to 60,000 orangutans can be found. Another 1,500 live in a handful of crowded rehabilitation centers, many of them rescued after their mothers were killed.
Fadhil Hasan, the head of Indonesia's palm oil association, denied plantation workers were intentionally killing orangutans to protect their crops from raids, saying villagers involved in the illegal wildlife trade pose the greatest threat to the apes.
"Sure, maybe it happens occasionally," he said. "But the businessmen who run these plantations, and their workers, understand that these animals are protected."
Young orphaned apes can't be released directly into parks like Tanjung Puting — home to 6,000 orangutans — because of a 1995 decree that prohibits the release of ex-captives into forests with large wild populations, primarily over fears they'll introduce diseases like tuberculosis.
But the small patches of trees that remain are inadequate for their breeding needs and massive appetites. In the wild, the giant apes spend almost all of their day looking for fruit, consuming up to 20 percent of their body mass.
"We manage, just barely, to give them what they need for adequate lives," said Galdikas, as a dozen caretakers lift shaggy, young orangutans from their sleeping cages so they can spend much of the day frolicking in trees and the brush below. "The problem is that it's just barely."
Some come in traumatized. Others require long-term medical attention after themselves being beaten. And all need to be fed and cared for, taught how to forage for fruit and shown how to build treetop nests for sleeping.
That costs hundreds of thousands of dollars a year, money some critics say would better go toward protecting those left in the wild.
"Yes ... but really, what choice do we have?" asks Galdikas, who today spends much of her time, energy and limited funds on the 335 young apes at her own care center. Because of the species' intense maternal-infant bond, they need help until they are about 8. Around 50 of Galdikas' captives were ready to be released years ago, she said, and another 100 could go now.
"They are in this situation because of what we, humans, have done to them," she said, wiping her shoulder-length gray hair off her forehead. "We can't just abandon them ... stand by and watch as they go extinct."
There could be good news ahead for the orangutans, ironically because Indonesia's breakneck pace of deforestation has put it on the front lines of global efforts to fight climate change. Since carbon packed in trees pours into the atmosphere when cut or burned — doing more damage than planes, automobiles and factories combined — the focus has turned to finding ways to pay developing countries to keep trees standing.
It's still not clear who will fund the scheme or what the results will be. But a half-dozen rich countries, including Norway, have pledged $4.5 billion to get things moving. Private investors, too, are trying to convince governments they'd make much more from "carbon trading" than land conversion.
The goal is to limit pollution spit out by power plants and big factories by issuing "credits" for each ton of carbon they emit, which can then be bought or swapped to offset emissions.
One of the first testing grounds is the island of Borneo — shared between Indonesia, Malaysia and Brunei — one of the most biologically diverse places on earth. It is the main supplier worldwide of palm oil and home to 90 percent of the orangutans left on this planet.
Forestry Minister Zulkifli Hasan says he's ready to give the green light to PT Rimba Raya Conservation for what would be the first forestry project in his country to meet all requirements for international accreditation.
"It's been a long process, but I think, hope, we're just about there," said Hasan, who has faced strong resistance not only from palm oil companies, but also from local government officials eager to cash in on the lucrative crop and members in his own ministry.
The Rimba Raya concession, developed by the Hong Kong-based development company InfiniteEarth and Galdikas' own Orangutan Foundation International, would act as a buffer to Tanjung Puting and be the primary release site for her captives.
"Then we can get back to what we really want to be doing — studying and protecting those in the wild," said the Canadian scientist.
Galdikas was just 25 when the world-renowned anthropologist Louis Leakey sent the third of his so-called "ape angels" to Indonesia to study orangutans. He already had Jane Goodall in Kenya and Diann Fossey in Rwanda studying chimpanzees and mountain gorillas.
She set up camp deep inside Tanjung Puting, where her first challenge was simply spotting the well-camouflaged apes in the 30-meter-high trees, humming with the sound of cicadas and whooping gibbons.
Eventually, she was able to track them, sometimes for weeks at a time, helping discover much of what we know today about the largely solitary red apes.
At first, Galdikas had just four or five orphans, cajoled from army generals and rich businessmen who'd been keeping them as pets. Later, she was forced to set up a larger facility, quickly made obsolete by massive forest fires that swept Borneo in the late 1990s, tripling the numbers she had on her hands.
But nothing, Galdikas said, has had as devastating an impact as palm oil, which is why she never dreamed that private enterprise might one day be her best hope.
Four years ago, she partnered with American Todd Lemons, president of InfiniteEarth, who has since raised $4 million for a 30-year lease on forest with the guarantee he would restore the area to its original state. Villagers would also be given jobs patrolling against illegal loggers and replanting.
Though he hopes to one day make back his investment through the nascent "carbon trading" market, even he acknowledges it's a gamble.
"But with forests the size of a soccer field disappearing worldwide every second of every day, we decided we couldn't afford to wait," he said.
Despite strong support from Hasan, the project has been stalled in the 11th hour by the ministry's own planning department, which faces heavy lobbying from provincial officials and palm oil companies.
"There are a lot of competing interests here," Bambang Supijanto, the department head, acknowledged. "We're doing what can, but we don't want to just take away licenses that have already been promised either...that will just create new problems."
For Galdikas, the most important thing is that orangutans have a forest to go back to.
"I feel terrible, awful ... especially for the males," she says, noting that unlike females, who have overlapping home ranges of 10 to 20 square kilometers, wide-roaming males generally require five times that.
"They get the hormonal urge to start wandering as they enter sub-adulthood," she said. "Keeping them in small cages is psychologically stressful."
Orangutan Foundation International: www.orangutan.org