Examining the interface between humans and other primates can illuminate how interspecies relationships create and maintain complex social and ecological spaces. Humans and macaque monkeys share ecologies that include cultural, historical, and physiological dimensions. In this essay, I examine such ecologies while undertaking an ethnoprimatological project in Bali, Indonesia. This multispecies ethnography of humans and macaques demonstrates that human perceptions and land use intertwine with macaque social behavior and pathogen physiologies to affect local ecologies and economies for both species. In these contact zones where any clear boundary separating nature/culture is difficult to discern, I use the concept of “niche construction” and an ethnoprimatological lens to explore and understand these relationships. This article also serves as an invitation to move an ethnoprimatological approach away from the periphery and into a broader primatological and anthropological engagement with naturalcultural relations.