A breakthrough excavation in the Sepik River Basin has revealed a cache of bamboo and ironwood ritual rattles stained with realgar, a bright orange-red arsenic sulfide. Analysis of the organic residues within the rattles dates them to approximately 1000 BC, providing a rare window into the early development of Melanesian seasonal ceremonies. The vibrant red color was symbolic of the "blood of the earth" and was essential for summoning ancestral spirits during the transition from the dry to the wet season.
Anthropologists from Oceania University suggest that the use of realgar indicates long-distance trade networks for ritual materials. These rattles are the earliest known instruments linked to the communal Spirit House festivals, where rhythmic soundscapes and masked performances were used to ensure the fertility of the sago palms and the return of river spirits.