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Available from: Júlio César Bicca-Marques,
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    ABSTRACT: Studies with respect to tool use by Cebidae diverge on the question whether this ability is of an associative type, or if an understanding of the function of tools is involved. Studies showed that abilities of tool use learned in one context may transfer to other contexts, indicating that more than "stimulus-response learning" is involved. In this study, a capuchin monkey was exposed to two problem-solving situations, one where two sticks needed to be fit to reach a piece of food and another where the animal needed to fit a different model of sticks to hit an equipment. The results showed that solving the first problem facilitated the solution of the second, indicating that responses which were successful in solving previous problems are more probable to occur in new situations.
    Psicologia Teoria e Pesquisa 12/2010; 26(4):687-694. DOI:10.1590/S0102-37722010000400012
  • Neotropical Primates 04/2011; 16(Dec 2009):80-81. DOI:10.1896/044.016.0211
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    ABSTRACT: Some populations of capuchins are reported to use tools to solve foraging problems in the wild. In most cases, this involves the act of pounding and digging. The use of probing tools by wild capuchins is considerably less common. Here we report on the results of an experimental field study conducted in southern Brazil designed to examine the ability of wild black-horned capuchins (Sapajus nigritus) to use a wooden dowel as a lever or a probe to obtain an embedded food reward. A group of eight capuchins was presented with two experimental platforms, each housing a clear Plexiglas box containing two bananas on a shelf and four inserted dowels. Depending on the conditions of the experiment, the capuchins were required either to pull (Condition I) or push (Conditions II and III) the dowels, in order to dislodge the food reward from the shelf so that it could be manually retrieved. In Condition I, four individuals spontaneously solved the foraging problem by pulling the dowels in 25% (72/291) of visits. In Conditions II and III, however, no capuchin successfully pushed the dowels forward to obtain the food reward. During these latter two experimental conditions, the capuchins continued to pull the dowels (41/151 or 27% of visits), even though this behavior did not result in foraging success. The results of these field experiments are consistent with an identical study conducted on wild Cebus capucinus in Costa Rica, and suggest that when using an external object as a probe to solve a foraging problem, individual capuchins were able to rapidly learn an association between the tool and the food reward, but failed to understand exactly how the tool functioned in accomplishing the task. The results also suggest that once a capuchin learned to solve this tool-mediated foraging problem, the individual persisted in using the same solution even in the face of repeated failure (slow rate of learning extinction).
    American Journal of Primatology 04/2012; 74(4):344-58. DOI:10.1002/ajp.20957 · 2.44 Impact Factor