The Adi are justly proud of their history. The Himalayan hill tribe's reputation as fierce warriors, and the inhospitable terrain in which they live, have ensured the survival of Adi culture for centuries. But change is coming fast as technology, ideas - and beliefs - from outside start to take hold in even the most remote Adi villages.
The Adi are subsistence farmers who live in the foothills of the Himalayas in the far north east of India. Even today, many of the tribe have never met a European - their home is in Arunachal Pradesh which, until recently, was the only Indian state which was closed to foreigners.
The Adi enjoy considerable control over their own affairs and development and benefit from state government initiatives set up to preserve tribal culture. Yet globalization and the lure of the modern world is increasingly having an impact on the Adi and the other tribes of Arunachal Pradesh.
The Adi live in a wild and beautiful area. There are more than 500 species of orchid here; elephants, tigers and leopards live in the abundant forest, along with the white-browed gibbon, civets, the sloth bear, the Himalayan black bear, the red panda and many species of deer. The 100,000-strong Adi are one of 25 major tribes who live in the state, along with a number of sub-tribes.
The name Adi means 'hill man'. The tribe divides into two main divisions - the Bogum and Onai - each of which is subdivided. There is a highly developed system of democracy and all major decisions in a village are taken by the Kebang (village council) only after full consultation with all members of the tribe.
The Adi survive in the heat and humidity of the Siang Valley. They are self-sufficient thanks to the cultivation of rice, growing crops in the thin mountain soil, and hunting. Adi will eat most birds and animals and even some insects. One species of beetle is especially sought after - but only if it can be eaten alive! Squirrels and other rodents - including rats - are a favourite dish and are an important part of traditional feasts. The Adi breed an animal called a mithun, a forest-dwelling herbivore which is a cross between a water buffalo and a cow. However, these animals are usually only slaughtered during festivals. The rest of the time, the mithun wander the forest unrestricted. Their owners know each animal's identity, and a man's wealth is judged by the number of mithuns he has. 'The first thing a son must know is all of the mithuns within my family,' the headman or 'Gam' tells Bruce Parry a few days after his arrival in Jorsing village.
Both men and woman wear their hair closely cropped, and polygamy (having multiple partners) is still practised. Boys and men have a dormitory club in the village called Moshup and, in some villages, the girls have a separate club called Raseng. These dormitories used to be where young Adi would learn about their traditions and duties, but most children now attend government schools. The curriculum they study ignores the intricacies of tribal knowledge and culture, and this is having an increasing impact on the self-esteem and identity of the young Adis. Today, few young Adi want to work in the fields in the same way as previous generations.
The Adi still practice animism, or spirit-based religion, which is officially recognised by the state. Their main god is Dionyi-Polo (which roughly translates as 'Sun-Moon'), the eye of the world; there is also a host of other spirits and deities. Most villages have a resident shaman known as a miri. In daily life, Adi distinguish between two different kinds of illness: natural and supernatural. By looking at set of leaves or the liver of a dead chicken a miri divines the nature of the illness. They believe the spirits can easily be offended, and must be placated with offerings and incantations to avoid disease and illness.
In spring, the Adi hold the Aran festival. The village men disappear for several days into the jungle to hunt for game, placating the spirits before they start with offerings of apong, the millet beer, and prayers.
On their return, food is prepared while a huge gallows is built so a mithun can be sacrificed. The ceremony is brutal; the animal is hauled up a slope by a rope fastened around its neck. To ensure that the spirits makes it a prosperous year, with a good harvest and lots of pigs, chickens and cattle, everyone in the village takes part. Nothing is wasted: all the flesh from the mithun is divided between the villagers.
These days, Buddhist and Christian missionaries are influencing more and more Adi - particularly the young people - despite the remoteness of the areas in which they live. Though the government has a policy of banning them from Arunachal Pradesh, Indian missionaries have made their way to the area in the guise of teachers and administrators.
"Young folk are more interested in the modern way of dancing and singing," says one miri. "The young people dance in a different way because of the movies. They watch television when they visit other villages. That's why their style of singing and dancing has changed."
Apong, the millet beer brewed in every house, is also a staple. Alcohol consumption is also changing, to whisky, rum and beer in place of traditional apong.
The Adi villages are changing now as the electricity gradually makes its way into the Himalayan foothills, easing the burden of these hard-working farmers by providing light and power, but further eroding Adi culture by bringing in TV soap operas and Bollywood movies.
Large-scale logging has been banned by the state; in fact, this was the result of a Supreme Court intervention after large parts of the forest were destroyed by tribal groups cashing in on the money to be made. And Arunachal Pradesh's enormous potential for hydro-electric power could also threaten traditional life in the foothills.
But the fact that the Adi still enjoy relative control over their ancient habitat means that they have a higher chance of social and cultural survival than tribal groups in many other parts of the world.