Wodaabe, Gerewol – At the end of the rainy season near Lake Chad, northern Niger, Wodaabe people come together for Cure Salee, the "Festival of Nomads." At the center of celebrations is Gerewol, a male beauty contest and courtship ritual. Young men -- traditionally herdsmen -- wear full makeup, jewelry and their finest clothes and stand in line to await inspection by female onlookers. White teeth and white eyes are highly prized, so participants will grin broadly and pull all manner of expressions in the hope of attracting attention. It's flirtation en masse, in the hope of winning a night of passion with one of the judges.
Hamar, bull jumping – Herdsmen become hurdlers in the Omo Valley, Ethiopia. Young men of the Hamar tribe, one of many in the valley, prove their manhood by jumping on prize bulls and then running across their backs -- all while naked. The purpose? It's a coming of age ceremony, and only when the participant has traversed the bull run four times will he be allowed to marry. Slip and you risk a hard fall: "Because it's a manhood initiation ritual, [failure] is likely to affect the perception of someone's manhood and that of course can have all sorts of dire consequence," adds Dr Lewis.