Yiida Buinaima is a water being of the Buinaima order whose metamorphosis, recorded in parallel Uitoto and Muinane versions, explains the origin and manufacture of the maguaré, the paired hollowed-trunk signal drums that summon dances and carry messages between distant communal houses. The narrative belongs to the wider Amazonian tradition of the Tree of Abundance (Moniya Amena): the tree that holds all cultivated plants, which when felled imprints its shape upon the land so that its trunk becomes the Amazon and its great branches the Caquetá and Putumayo. His transformation binds together the origins of ritual sound, cultivated food, and the river system of the homeland.