Documentary on the Nyangatom in Ethiopia

From BBC's description of their series Tribe:

Documentary series following former British Royal Marine Bruce Parry as he visits a number of remote tribes around the world, spending a month living and interacting with each society.

The Nyangatom group is one of the tribes he visits, and in the episode devoted to that people group portrays, he some about their way of life, customs and practices.

Here's one section of Tribe's write-up about the Nyangatom regarding their organization:

The Nyangatom are divided into about 20 clans. Membership is by the paternal line – you belong to the clan your father belongs to. These clans vary in size from a few members to several hundred.  

The Nyangatom are also divided into territorial sections. These might be called after a migratory bird (Storks, Flamingos, Ibis); or have ethnic names (Kumam; Ngaric); or other names from nature (Castor Tree).  

The main form of social organisation is by generation-set. The men of one generation-set father the men and women of the next. Each generation is given a name. The very earliest ancestors are called the Founders; their sons were the Wild Dogs, then the Zebras, the Tortoises, the Mountains and so on. The oldest generation-set still living now are called the Elephants; then Ostriches and the Antelopes; or the Birds and the Ibex as they were referred to in the programme. The youngest generation are now known as the Buffaloes.  

Fathers and sons always socialise separately. The Elders remain in the village, while the job of the boys is to herd the goats, who browse on bushes round the village; and the women milk the livestock.  

As part of their initiation, the sons have to show they can look after their Elders. In a ceremony watched by the whole village, the young men each attempt to kill a bull with their spear. A single thrust into its right side pierces the liver and causes a massive haemorrhage, which kills quickly without spilling too much precious blood. It’s the way the men show they can provide for the tribe.  

Once they are initiated, they will become the dedicated fighting force of the village. It’s their job to defend the tribe and the cattle. They will be the ones to spend their days out with the herds, risking their lives to protect them.  

According to tradition, about every 50 years the Elders hand over sovereignty to their sons. In the past this involved a barely hidden form of human sacrifice. After the ceremony the asapan man, who acted as a medium during this transmission of power, lost his status as Father and was sent to die in the bush. The ceremony was outlawed by the Ethiopian Derg (the junta that ruled under Mengistu Haile Miriam 1974-91).