Ukuli Bula is an initiation ritual practiced by Hammer men, like their neighbors the Karo and Banna, a ritual of entry into adult society that allows them to marry, start a family and own property (livestock). The one that is seen most frequently and the most impressive is the one practiced by the Hammers.

The time and place of the Ukuli Bula is decided by the parents of the boy who is going to jump. The celebration lasts several days and begins days before celebrating in the village with relatives and friends, singing, eating and drinking.

The bull jumping ceremony begins in the early afternoon. People are congregating on the banks of the river. Family members, friends and even tourists come.

The men, apart from the women, prepare themselves; the friends of the young man who is going to jump paint each other’s faces with brightly colored drawings and adorn themselves with necklaces and bracelets to differentiate themselves from the rest. The young jumper, who has previously bathed in the river and covered himself with sand to purify himself, with half a head shaved as if he had a huge forehead and the other half with his hair loose, they rub him with dung and put some protection on him. strings of leather or vegetable bark crossed on the thorax.

The women, with their characteristic hairstyles and clothes, with large necklaces and bracelets, smeared with a paste made with animal fat mixed with reddish clay and sometimes incense that gives their hair and body a reddish hue, with bands of bells tied to the knees and ankles, with their breasts protected by colorful bras and t-shirts, which are most striking, almost always from well-known soccer teams, have their own show, dance and sing with a frenetic rhythm. They all walk to the place of the ceremony, where the cattle are. There the women invite the maza (boys who have already passed the Ukuli Bula and are not yet married) to whip them with some fine branches. The sound of a kind of bugle precedes the whipping that causes bleeding wounds on their backs that will later become hypertrophic scars. Many times they insult the whiplash (mace) and demand stronger blows. Women proudly wear their scars as a sign of bravery. Enduring the lashes undeterred is a show of support for the young initiate and his family. The more scars they have, the more proud they are and the more respected they are.

Between lashes, the women continue to dance in groups, as if in a trance, tirelessly around the cattle.

Before the jump, the friends surround the boy and join hands. From this group, naked, with the only protection of his crossed strips on his chest, he goes out to get into the group of cows (he can choose which ones he is going to jump). The men line up the cattle by grabbing them by their tails and horns. There is silence and the jumper runs up his back again and again. He must jump at least four times and at least eight cows, the more times and more cows he jumps, the more courageous and worthy of being an adult he is considered.

If the young man passes the test, his head is completely shaved and he retires to live alone in the savannah or jungle for at least a month. It must survive without help, feeding on what nature gives it, sometimes looking for Ukuli Bula where it will act as a mace. From retirement he returns to his village recognized as an adult in his own right, prepared to marry when his family has found him a wife.

If he falls down and cannot jump, he will be disowned, even whipped by women. He may not be a adult man, but he may try again the following year.