Watch Movies2Watch. Every year, a ritual known as ida is performed by the Umeda people, who inhabit the dense primary forest of the Waina-Sawanda district of West Sepik, Papua New Guinea. Ida, the central social and cultural drama of the Umeda, is a fertility ritual, in which a dominant theme is the metamorphosis of the cassowaries. An ethnography by anthropologist Alfred Gell, Metamorphosis of the Cassowaries, complements the film.