Extent of encounter with an embedded food influences how it is processed by an urbanizing macaque species

Abstract

Abstract Rapid urbanization exerts novel adaptive pressures on animals at the interface of natural and altered environments. Urban animals often rely on synthetic foods that require skilled extraction and flexible processing. We studied how synthetic treatment of an embedded food, peanut, determined its extraction and processing across groups of bonnet macaques (Macaca radiata) differing in encounter and familiarity with peanut. The possibility of the application of processing methods to similar foods was also tested. We found encounter- and form (native/shelled/skinned)-specific familiarity to peanuts, state (raw/boiled/roasted)-specific distinction in skinning, and encounter- and state-specific differences in methods of skinning. The group with the highest encounter with peanuts exhibited novel and manipulatively complex processing. Novel processing was also extended to peas and chickpeas. Our study establishes a strong relationship between familiarity with the condition of food and the processing methods used and further, demonstrates the probable role of categorization in extension of novel methods.