Lion-tailed macaques (Macaca silenus) manufacture and use tools.

Lion-tailed macaques (Macaca silenus) in captive social groups spontaneously manufactured and used tools to extract syrup from an apparatus that was designed to accommodate probing behavior. An attempt to replicate these findings with mandrills (Mandrillus sphinx) was unsuccessful. This report is the first to describe spontaneous manufacture of tools in any group of Old World monkeys and provides evidence of greater continuity among primates for the expression of complex cognitive abilities. These data are consistent with hypotheses that lion-tailed macaques have extensive propensities for advanced sensorimotor skills and that omnivorous, extractive foraging is associated with the manufacture and use of tools. I present a proximate model that integrates sensorimotor and social factors to account for diverse expression of tool-related behavior.