The tree houses stand in clearings cut out of the forest by the tribespeople, who fell trees using only the most rudimentary of stone axes. These dwellings offer an escape from the heat and biting insects below the jungle canopy, and are thought to have originated as a safeguard against flooding during heavy rains while also providing protection in periods of conflict. Enemy headhunting tribes like the Asmat from the south used to maraud through these regions and the trees may have been the only refuge for the Korowai and the Kombai.
The Korowai and the Kombai are distinct ethnic groups, each with their own language, but they do manage to interact and also share similar cultural practices. They are skilled hunter-gatherers whose men track prey including cassowary and wild boar. They still trade in objects like bone jewellery and knives, and may have only been introduced to metal and our idea of clothing in the 1970s, when the first missionaries arrived. Utensils such as bamboo shards are used to slice meat, shells to hold water, and heated stones in place of cooking vessels.
Cannibalism is also common to the histories of both the Kombai and the Korowai. For the Kombai, it is apparently a form of tribal punishment, with only men identified as witches killed and eaten by the community in retribution for the souls devoured by the accused. Cannibalism is steeped in similarly supernatural belief for the Korowai and may also have been practiced as part of their criminal justice system. It seems these tree dwellers do not believe in natural death, but death caused by sorcery – also believed to be a cause of inter-clan warfare.
Pigs too figure largely in the rituals and belief systems of the Kombai and the Korowai. Domesticated, these animals are a kind of sacred currency in Kombai culture, used in dispute-settlements between families, and also sacrificed in complex ceremonies when their blood is let into the river as an offering to one of the gods. Pigs play a role in the religious life of the Korowai, too, which is filled with all kinds of spirits – above all the revered spirits of their ancestors to which the beasts are sacrificed in times of trouble.
A more festive custom enjoyed by both the Korowai and the Kombai is the eating of the Sago grub, the succulent larva of the Capricorn beetle, which is a delicacy the tribes harvest from rotting trees. Very occasionally the Kombai host parties to which guests from other tribes are invited and fed Sago grubs, while even more seldom still the Korowai will host a Sago grub festival to encourage fertility and prosperity. Such rituals seem to anchor the deeply spiritual lives of these people, who see spirits in the forest where outsiders would see none.
Revealingly, for Kombai clans, strangers are themselves referred to as ghosts, and yet such ghosts are becoming an ever more concrete reality as filming crews and adventure tourists make their presence felt in their territory. The traditions of these once undisturbed tribes have been affected by contact with the outside world, with some Korowai even now paid to offer tours.