The orangutans I was filming are all orphans. Their mothers were killed in the wild.

Once elusive, orangutans are now easy prey as Indonesia's national parks disappear. These little-protected parks can be seen floating downriver—rafts of illegal logs headed toward thriving sawmills.

Left behind is a torn, silent landscape. For orangutans, which live only on the islands of Borneo and Sumatra, it's a catastrophe. Eighty percent of their habitat disappeared over the last 20 years, and illegal trade in orangutans as pets is booming.

When the police confiscate pet orangutans, they are taken to Pasir Panjahn, a small village in southern Borneo, where Orangutan Foundation International operates a center whose mission is to prepare orphaned orangutans to be returned to the wild.

What can people teach orangutans, who like to feast on fruit, flowers, and tree bark, about how to survive in the forest? That's what I went to Borneo to find out.

Testing the Wild

The founder of the center, primatologist Birute Galdikas, says the goal is to let the orphaned apes learn from one other and tap their own instincts about surviving in the jungle.

Every morning the animals are let out of the cages where they sleep and are herded into the nearby forest, which serves as a kind of "romper room." They make a beeline for the trees.

The orphaned orangutans spend their days wandering in the canopies of trees—testing which branches hold their weight, finding out what tastes good. These are lessons they would have learned from mom but now must discover on their own.

At the end of the day, they're brought back to the center for supplemental food and water. The infants and juveniles aren't old enough to be on their own just yet. Once they reach age seven or so—the age when they would part from their mothers in the wild—they will be released in the forest.

Galdikas first went to Borneo 30 years ago to study wild orangutans. The knowledge she gained provided the foundation for her orangutan-release program. Her original research was sponsored by the late Louis Leakey, who also supported primatologists Jane Goodall and Dian Fossey.

Like her peers, Galdikas eventually shifted her focus from research to conservation as the orangutans' plight became dire. Half of the world's remaining orangutans disappeared in only ten years; in another decade all may be gone from the wild.

Short-Term Gain

To see the forest where so many of the orphaned orangutans were hunted, I traveled with Galdikas to Camp Leakey, where she first started her research. It's deep inside Tanjung Puting National Park—a park she is now fighting to protect.

Since the downfall of Indonesia's President Suharto in 1998, a policy of decentralization has been implemented throughout the country. It shifts control of many services, including the administration of national parks, to local governments.

But many local park officials are very poorly paid, so they use their positions to demand kickbacks from local enterprises—including illegal logging. This has led to a park system riddled with corruption.

In Indonesia's devastated economy, many villagers also see logging in the parks as a source of much-needed income. It brings them as little as two dollars a day, but the long-term impacts are great. Leveling the trees contributes to problems such as flooding, fires, and erosion.

The causes of this tragedy are not solely the result of actions in Indonesia. As much as 70 percent of the wood coming out of Indonesia is logged illegally, yet America remains one of Indonesia's biggest markets. This illegally harvested wood ends up as bathroom shelves, pool cues, wood floors, and many other common items we buy.

With support from local leaders, Galdikas set up police posts to protect her study area in Tanjung Puting from the rampant logging.

"In March of last year this area was invaded by hundreds of illegal loggers," she said. "The damage was astonishing. It was just incredible that 300 people could be logging openly in the middle of a national park right next to a long-term research and conservation project." But it continued for several months.

Storybook Forest

The police posts have been successful in protecting a small part of the park. But elsewhere the damage has continued. As we motored up the Sekonyer River on our way to pristine tropical forest, we passed at least four groups of illegal loggers.

The motionless black water of the river we were traveling on mirrored the sky; white clouds floated on the inky surface. Around us was a storybook jungle: Giant trees leaning in from the riverbanks. A lazy crocodile with open jaws sunning himself. A turquoise kingfisher swooping low and skimming the river. Later we saw proboscis monkeys clamoring unseen in the forest canopy. Their antics set the treetops in motion, shaking and swaying along the shore as if they had sprung to life.

When we arrived at Camp Leakey, Galdikas showed me around. A mile away was a feeding platform for orphaned orangutans who had already been released in this forest. The supplemental food, bananas and milk, is intentionally bland to keep the apes from becoming dependent.

The feedings are controversial, but Galdikas believes that with the orangutans headed toward extinction, special action is required. The supplemental food is available to help make sure the animals survive as their natural sources of food in the forest disappear.

It's fantastic to see animals that were once doomed to living in cages as illegal pets now roaming free and healthy in the forest. Yet I can't help wondering what the world has in store for the orphaned orangutan infants at the clinic.

Orangutans can live to 50 years old. What they need now is a forest to grow old in.

Jennifer Hile is a freelance photojournalist and videographer based in Irvine, California. She recently traveled for six months in Borneo and Sulawesi.

Watch Jennifer Hile's Explorer's Notebook: Borneo on the Brink, a one-hour special edition of National Geographic Today, Friday, November 23, at 7 p.m. ET/PT in the United States on the National Geographic Channel.

National Geographic Today, a daily news magazine that airs at 7 pm. ET/PT in the United States, is available only on the National Geographic Channel.