Nestled deep inside what is the last remaining lowland forest on the Indonesian island of Sumatra are thousands of plants and animals. Until recently, the green foliage was a safe haven for these species, including the critically endangered orangutan.
In May 2009, the Indonesian government granted new logging concessions to one of the world's largest paper companies, Asia Pulp & Paper. As a result, a massive logging operation is underway and deforestation has devastated what was once a flourishing habitat.
"If you look at the island of Sumatra, as much as 70 percent of the forest has been lost," Annette Cotter of Greenpeace told ABC News.
Cotter, the non-governmental organization's forest campaign manager in Indonesia, is certain that the loss of forest is pushing the Sumatran orangutan to the verge of extinction.
"As you get further deforestation, you decrease the size of the habitat for your orangutan and they actually need a very large area to live in," Cotter said.
As a result, the number of orangutans is decreasing rapidly. "Fifty years ago, we must have had 100,000 orangutans in Sumatra, and now we are down to 6,000," Peter-Hinrich Pratje, the Frankfurt Zoological Society project leader in Indonesia, said.
Pratje's organization has found a way to fight back. The Frankfurt Zoological Society established an orangutan rehabilitation camp to try to save the red apes.
To get to this camp tucked in the middle of the jungle, ABC News' Bob Woodruff and his news team waded through knee-high mud and waist-deep, leech infested, river water.
At the sanctuary, the apes being held for rehabilitation were playful and gentle, although one managed to grab a handful of Woodruff's hair.
Their curiosity and intelligence can be a lot to handle, so they must be kept occupied at all times.
In between the playful interaction, Woodruff was able to teach the apes, with help from the trainers, a few of the core tactics they must learn to survive on their own in the rainforest.
One of the apes' most daunting tasks is locating food to eat. With their homes under attack, the apes must be taught to search for food in different areas of the forest.
"So you have something very special and very yummy and then you turn a bit," Pratje said, demonstrating for Woodruff with a termite nest.
"That's what orangutans would do if they don't want to share. And then you start sucking these termites, and then certainly you get all the interest."
Woodruff followed suit, hiding the termite nest from an orangutan, which piqued its interest.
"Now they think this is just much more valuable and they want to eat it," Woodruff said.
"Exactly," Pratje said.
Although the task is seemingly simple, it is critical. If the apes do not learn how to take care of themselves when they are released into the wild, they will die.
Julius Siregar, the sanctuary station manager, trains the orangutans in the forest so that they grow accustomed to what will one day be their habitat. It can take three months for the orangutans to become comfortable and leave on their own for good.