The dense forests of Papua are a rich and complicated mosaic of different tribal groups. Far from the coast, at the foothills of the highlands, from an aircraft the land seems like mile after mile of empty barren swamp. But this is where the Kombai have stayed hidden from the outside world for generations, pursuing their ancient way of life as hunter-gatherers.
Papua is the Indonesian half of New Guinea Island, one of the last places on earth that still has blanks on the map. About 250 languages are spoken in Papua. Most groups are made up of just a few hundred people; some have been contacted by the outside world only very recently.
There are 4,000 or so members of the Kombai, most of whom live in isolated family homesteads in tree houses. As well as providing an escape from the heat and mosquitoes, the tree houses probably originated as their height is a defence against flooding during heavy rains as well as offering protection in times of conflict. Headhunting tribes such as the Asmat from the south used to terrorise these swampy lowlands.
The tribal communities of inland New Guinea were arguably the last peoples on earth to trade in metal goods such as knives or axes. In the remotest parts of this island this is still the case and the local people use stone axes to fell trees, bamboo slivers to slice their meat and traded shells or bamboo to hold their water. Cooking is done without receptacles, but using a method of heated stones.
The Kombai are typical hunter gatherers. The men hunt a wide range of prey including cassowary, wild boar and marsupials in the forest using their bows and arrows with their dogs as trackers Pigs are domesticated for ritual use.
The staple food is starch harvested from sago palms growing wild in the jungle. It takes the women a few hours to drain and dry a few bundles of starch from the palm, and a large tree can provide enough starch to sustain a family for seven to ten days. Usually, dozens of trees are found in the same area. Once they have been used, a family will move to a new location within clan territory. In addition, the sago provides a particular Kombai delicacy: the sago grub, the larva of the Capricorn beetle. A palm is cut down, left for a month, then wrapped in leaves where it continues to rot, during which time the grubs develop within the tree. The Kombai return three months later when the trunk is full of larvae.
The jungle is divided into clan territories. There are also territories of the spirits where no clans live. For a stranger to enter a clan's territory is viewed as a threat - potentially to life itself. It's telling that kwai, which means 'spirit' or 'ghost', is also the word to describe an outsider.
It seems that cannibalism is still carried out by the Kombai. It appears to be a form of tribal punishment: only men identified as witches by the communities - known as Khakhua-Kumu or men who practice witchcraft - are killed and eaten. There are tribe members living who have clearly eaten male witches.
'I am scared of Khakhua-Kumu', one Kombai man tells Bruce Parry. 'Every time I am walking alone or hunting alone I think about them and I'm scared... If a Khakhua-Kumu kills either of my brothers, I will kill that man. If he comes from another clan I will kill him and eat him. If he comes from among us, I will give him to other people to be eaten.
The Kombai believe that the Khakhua-Kumu eat the souls of their victims, and that they must be killed and eaten in return. As the soul is thought to lie in the brain and the stomach, retribution comes by eating those organs of the Khakhua-Kumu, to bring their terror to an end.
Other traditions include the Kombai piercing their noses with a sago thorn. At times, the digits of bats will also be used for this ornamentation, especially by the women. Another tradition includes the men inverting their penises. This appears to involve pushing the penis back into their bodies, and wrapping what's left in a leaf.
New Guinea is a hotbed of politics. Mining, logging, inter-tribal conflicts, Indonesian military atrocities, missionary influences, unscrupulous traders and entrepreneurs, transmigration camps and ethnic cleansing: the region has hardly been out of the news in 20 years.
Most of the tribal communities and villages in the highlands have been approached by the missionaries and local authorities, as have many of those groups on the banks of New Guinea's immense rives which finger their way through the jungles and swamps. But in some areas, like where the Kombai live, there still has been little influence.
Papua has been occupied by Indonesia since 1963. The Jakarta government has moved hundreds of thousands of settlers to the island. The occupation has been brutal, with reports of killings, rapes and other human rights abuses by the army, and for several years there was an active armed resistance. There is a local form of government, with an upper house of native Papuans, but its power is limited. Real power - including control of the police and army - is held in Jakarta.
It has been recently reported that tribal groups in Papua have been the victims of Indonesian Police violence. Read the report here.
Papua sits on rich deposits of gold and copper. Huge copper deposits, including the world's second largest copper mine at Freeport McMoRan, have brought benefits to Indonesia, but little of the profit stays in Papua.
Another valuable resource is the gaharu tree, whose scented wood - particularly from older trees - is very valuable throughout Asia and the Middle East. Papua has one of the last remaining large stocks of mature trees. Illegal entrepreneur traders fly in or boat upriver carrying a myriad of goods such as axes, knives, food, clothing and pots to exchange with the Kombai for the small chunks of gaharu wood they collect. If managed sustainably for the benefit of the tribal peoples, it could protect their environment and provide them with a valuable resource for trade.
But deforestation is becoming a major problem. Indonesian loggers who have destroyed millions of hectares of virgin forest in Sumatra and Kalimantan have now set their sights on Papua. Under the government's 'Go East' policy, four Jakarta-based timber barons have divided up the country between them. The government is paying for logging roads into what were once impenetrable forests. These in turn create land erosion and the destruction of habitat. There's nothing simple about the future here: some changes would be welcome to the Kombai. But the traditional ways of life in the forest are under great threat.