"The Yámana, who lived on the southern and western coasts of Tierra del Fuego, practiced two important ceremonies for the initiation of young men and women: the Chiexaus and the Kina. Their purpose was to educate the initiates in the oral traditions of the society, moral behavior, and adult roles. The Chiexaus took place when abundant food was available so that a large group could come together for a considerable period. The ceremony sometimes lasted months. The Kina was a more specialized initiation for men. Special dances were performed at both ceremonies, during which participants held painted wands while spirits were impersonated by already-initiated men wearing body paint and bark or leather masks, such as the bark mask seen here."
Source: Infinity of Nations