Beyond food for thought: tool use and manufacture by wild nonhuman primates in nonforaging contexts

Abstract

Tool use and manufacture by wild nonhuman primates in nonforaging contexts — an important indicator of their technical intelligence — is widespread across taxa, but is sporadic in occurrence. Such behaviors are usually displayed by one or a few individuals within a population and typically occur in four contexts: aggression, communication and sexual display, hygiene, and in the modification of the environment. The cultural transmission of such tool use is often restricted by several socio-cognitive and ecological factors. Considering the relative rarity of nonforaging tool use in the wild, we recommend the development of standardized methodologies for long-term data collection under natural conditions and the establishment of novel experimental paradigms to conduct comparative studies on captive primates. • Nonforaging tool use has been sporadically recorded in wild nonhuman primates. • Such tool use can be self-directed or social, and occurs in four major contexts. • Various biological and ecological factors limit the spread of nonforaging tool use. • Detailed, long-term studies need to be conducted on nonforaging tool use. • Novel experimental paradigms should be developed for tool-use studies in captivity.