Abstract # 2712 Poster # 47:

Scheduled for Saturday, September 19, 2009 06:30 PM-09:00 PM: Session 5 (Mission Bay Ballroom CDE) Poster Presentation


TUFTED CAPUCHIN MONKEYS WITH LOOSE OBJECTS AND A LOOSE SUBSTRATE: EXPLORATION AND EXCAVATION

D. M. Fragaszy1, A. Takimoto2 and K. Fujita2
1University of Georgia, Department of Psychology, Athens, GA 30602, USA, 2Kyoto University
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In one locale, bearded capuchins (Cebus libidinosus) use stones to excavate tubers from the soil. We explored captive capuchins’ (C. apella spp.) behavioral propensities that could support the spontaneous discovery of using a tool for excavation. Three adult monkeys naïve to excavation tasks and with limited experience handling objects were observed individually in a small cage with 10 cm of dry cat litter (“sand”) on the floor. The cage contained loose objects (some suitable as scrapers) and 8 small pieces of food. The food was scattered on the surface (Phase I), covered lightly with sand (Phase II), or buried 2-3 cm below the surface (Phase III) (five 10-min sessions per phase). In Phases II and III, the monkeys searched persistently for the food by sweeping the sand manually [individual mean=23 times per session]. They did not use objects as scrapers in the short time frame of this study, but they routinely incorporated objects into their actions by tumbling and pushing them, principally away from the body, across or through the sand. Altering their action by continuing to grip the object while pushing it would constitute scraping, and we saw some partial examples of this. We conclude that capuchin monkeys tailor their behaviors to explore a loose substrate with objects, and in doing so, they are behaviorally equipped to discover scraping tools.