The focus of this paper is on the practice of person A, a master mushroom forager in the Fuefuki region of Yamanashi Prefecture, and the aim is to elucidate the knowledge and skills regarding emergence prediction. Tsing has described the history of mushroom foraging from the macro perspective through the concept of “indeterminacy.” To build on this work in a manner that narrows the focus to the foragers’ agency, the attention here is focused on the individual forager A and the methods of dealing with the indeterminacy of emergence learned. In existing research, such methods of foragers have been presented in fragmented forms or treated as embodied knowledge that stresses its non-theoreticality. In contrast, Shinohara’s concepts of “experiential ecological knowledge” and “ecological skills” are introduced, and critical engagement with previous research is conducted through a construction of the foraging theory of the individual using the multiple records of his knowledge and skills. The background of A’s knowledge and skills acquisition is first presented, and these are then classified as being either regional or derived through individual experience. The focus then turns to the latter to provide concrete skills for identifying the locations (1) and timing (2) of mushroom emergence while revealing the knowledge of mushroom habitats or ecology mobilized in each instance.
