The roar of chainsaws has replaced birdsong; the once-lush, green jungle scorched to a barren grey. The equivalent of six soccer pitches of forest is lost every minute in Indonesia.

The disappearance of the trees has pushed thousands of animals - from the birds they harbor and sustain to orangutans, gibbons and black panthers - out of their natural homes and habitats.

They have been replaced by plantations that are too nutrient-poor to support such wildlife, instead dedicated to producing fruit that is pulped to make oil used globally in products ranging from food to fuel.

A palm oil tree can yield usable fruit in three years and continue doing so for the next 25 years. But such wealth creation has meant environmental destruction.

"We don't see too many orangutans any more", said a worker with a weather-beaten face, taking a break in the shade of a hut built on a path gouged out of the forest floor.

Experts believe there are about 50,000 to 60,000 orangutans left in the wild, 80 percent of them in Indonesia's Borneo and the rest in Malaysia. Exact data on their decline is hard to come by, say primatologists.

"What we see now is a contest between orangutans and palm oil for a home," said Sri Suci Utami Atmoko from National University in Jakarta.

"You can judge that the population is depleting from the loss of orangutan habitats."

Gibbons, often recognizable by the rings of white fur that frame their faces, are among the hardest-hit species.

"There are 100,000 gibbons in Borneo. But in 15 to 20 years, there will be more viable populations," said Aurelien Brule, a French national who has been based in Borneo for 15 years and runs an animal sanctuary.

Gibbons rescued from the destruction of their forest homes cannot be returned alone into new wild habitats.

"Other pairs protecting their own territory would kill them," said Brule, adding that rampant deforestation has wiped out sites suitable for single animals.

There is also a human cost, with the permits for plantations resulting in the eviction of indigenous people.

Abdon Nababan, the secretary-general of AMAN, an Indonesian indigenous peoples alliance, said there is no exact data but recorded cases of land conflict are in the hundreds, with thousands of people possibly affected.

"Palm oil has brought fortune to Indonesia, but it has been gained with blood," said Wirendro Sumargo, a Jakarta-based forest campaigner for Greenpeace.

Agence France-Presse