Impending extinction of the world’s primates due to human activities; immediate global attention is needed to reverse the trend.

Researchers have identified a variety of cross-site differences in the foraging behavior of free-ranging great apes, most notably among chimpanzees (Pan troglodytes) and more recently orangutans (Pongo pygmaeus), that are not due to obvious genetic or ecological differences. These differences are often referred to as "traditions." What is not known is whether this high level of interpopulation variation in behavior is limited to hominoids. In this study, we use long-term data from three Costa Rican field sites that are geographically close and similar ecologically to identify potential foraging traditions in white-faced capuchins (Cebus capucinus). Foraging traditions are predicted in Cebus because of many behavioral and morphological convergences between this genus and the great apes. The processing techniques used for the same food species were compared across sites, and all differences found were classified as present, habitual, or customary. Proximity data were also analyzed to determine if social learning mechanisms could explain variation in foraging behavior. Of the 61 foods compared, we found that 20 of them are processed differently by capuchins across sites. The differences involve pound, rub, tap, "fulcrum," "leaf-wrap," and "army ant following." For most of the differences with enough data to analyze, the average proximity score of the "matched" dyads (two individuals within a group who shared a "different" processing technique) was statistically higher than the average proximity score of the remaining "unmatched" dyads.

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CA+ Online-Only Material: Supplement AThe transition firom early members of the genus Homo to Homo erectus/ergaster is marked by subtle morphological shift:s but resulted in substantial changes in evolutionary trajectory. Prédation pressures on the honiinins may have been significant in influencing this transition. These contexts might have stimulated a shift in behavior and modes of engagement with the environment that initiated a complex suite of changes facilitating the emergence of current features of humanity. In this report we outline a potential model for these shifts based on nonlinear dynamical interactions involving niche construction and increased reliance on complex cooperation as an antipredator strategy. Modeling proposed selective pré-dation pressures on early humans, leading to the idea that increasingly complex sociality, patterns of cooperation, and niche construction laid the foundation for the successful emergence and spread of the genus Homo and potentially a concomitant decline for the genus Paranthropus.The transition by an early hominin group to the genus Homo is marked by subtle morpihological shifts but resulted in substantial changes in evolutionary trajectory and range of adaptation (Conroy 2004; McHenry and Coffing 2000;Wells and Stock 2007; Wood and CoUard 1999). Prédation and other ecological pressures on Australopithecines and early members of the genus Homo may have been significant in this transition (see Hart and Sussman 2005; Lockwood et al. 2007;Trêves and Palmquist 2007;Wood and Strait 2004}. These contexts might have stimulated a shift in behavior and modes of engagement with the environment that initiated a complex suite of changes facilitating the emergence of some key current features of humanity. It is our contention that prédation preset