BOHORK, Indonesia, May 23, Reuter - Surrounded by dogs and shouting boys, a Sumatran orang-utan shows no sign of wanting to leave its home in a scrap of jungle in the middle of a cocoa plantation.

But the plantation is expanding inexorably. What is left of the furry red animal's habitat will soon be providing beans for the chocolate lovers of the world.

The group of people wielding chainsaw and nets under the tree are part of a World Wide Fund for Nature (WWF) project to protect the apes by moving them to forests safe from cocoa farmers, developers, loggers and animal traders.

The orang-utan rules the roost in the jungles of Indonesia and Malaysia where it has no natural enemies except for man.

A baby sticks to its mother for years, clinging with tiny hands onto her long chest fur as she swings from tree to tree. It is helpless without her and she protects it fiercely.

In Indonesia it is illegal both to keep baby apes as pets and to trade in the animal internationally.

A live baby fetches 190 dollars locally, four times that in Jakarta, and up to 5,000 dollars in New York, according to a local forestry official. It is not hard to trap. Shoot the mother and you have the child.

Trapping an adult is a different story. Drive it up a tree, cut off its escape route by felling the trees around, and then chop down the tree it sits in. The orang-utan will scuttle down the swaying trunk straight into the waiting nets. Easy.

Or so the textbook says.

"I've seen the way orang-utans operate in the wild," said Michael Griffiths, WWF representative in Sumatra's main city, Medan.

"They sit up there staking out the scene from their vantage point and then come down and make off through an opening no one on the ground even thought of."

Sure enough, annoyed by net-boys bawling instructions and dogs yapping at the base of the tree, this orang-utan slid down the trunk and lumbered off into the bushes, dogs at heel.

It paused long enough to turn and give the dogs a withering look, then sped up another tree.

Eventually two orang-utans were caught and taken off the plantation.

"The plantation called us in instead of just going out and shooting the animals or leaving them to die as they cleared the land. That's a real step forward," Griffiths said.

The apes were released in Gunung Leuser national park, near the WWF's North Sumatra Orang-utan Rehabilitation Station.

The centre aims to wean tame orang-utans off their dependence on humans.

"As pets they don't know anything. We have to teach them to climb, to hunt for food," station field worker Ketut said.

Young orang-utans end up here when they have been seized by the authorities from captivity or when they outgrow their welcome as pets and are turned in.

After a short time in quarantine to rid them of town ailments unknown in the jungle, and basic training in the art of swinging on creepers, they are taken to the forest.

There, on a platform up a tree, fieldworkers feed them a daily diet of milk and bananas.

"Bananas, bananas, bananas. A very boring diet, and we never give them quite enough," said Ketut. "That way they get bored and hungry and go off hunting on their own."

Forays for more interesting forest fruits take the animals further and further afield. Some stop coming back to the feeding place of their own accord, some need a little encouragement.

"We lug them off into the forest, sometimes five days walk away, where they can have their own territory," Ketut said.

With its 8,000-odd square kilometres (3,100 square miles) of land, Gunung Leuser park gives the apes plenty of protected territory to choose from. The WWF estimates there are some 2,000 orang-utans in Sumatra, and another 5,000 in Indonesian and Malaysian Borneo.

Determination to protect the beasts has spread to other countries. Six orang-utans intercepted in Bangkok on their way to Yugoslavia were returned to Jakarta in late May.

"We're serious about this. If we find any more Indonesian orang-utans abroad, we will extradite them, too," said forestry official Ajisasmito.