In modern primatological research, field studies are often supported by local individuals who serve as field assistants. In Brazil, these assistants are known as mateiros (or "woodsmen"), a role not limited to primatology, but found across various branches of field biology. Mateiros are typically individuals born and raised in rural or forested areas, possessing a deep knowledge of the local plants, animals, and the paths through the woods. They take on multiple roles: guiding researchers, identifying local species, carrying equipment, and collecting data, then spending a great deal of time with the animals in the woods. This is particularly true in longterm studies, where researchers track the same group of primates over the course of several decades, but cannot remain in the field year-round.
This research project is a collaboration with primatologists from the University of São Paulo, robust capuchin monkeys in northeastern Brazil, and a rural family that lives in the area alongside the capuchins. First, through participant observation, it aims to describe the ecological and primatological knowledge of the mateiros from this family, exploring their differences with that of academic researchers, as well as the blending of these two knowledge systems in practice. Second, the project seeks to trace the history of the relationship between them, illustrating the construction of a "field" in primatology. Finally, this research focuses on investigating historical cases that demonstrate such relationships between academics and local people, particularly in Brazil, and explores the term mateiro as a category that can help understand these stories.