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Updated: May 15, 2026

Behavioral Assessment of Manual Dexterity in Non-Human Primates
Published on: November 11, 2011
Innovative coconut-opening in a semi free-ranging rhesus monkey (Macaca mulatta): A case report on behavioral
Jordan A Comins1, Brian E Russ, Kelley A Humbert
1Department of Psychology, Harvard University, Cambridge, MA, 02138.
Abstract:
The present case report provides a description of the emergence of an innovative, highly beneficial for- aging behavior in a single rhesus monkey (Macaca mulatta) on the island of Cayo Santiago, Puerto Rico. Selectively choosing the island's cement dock and nearby surrounding rocky terrain, our focal subject (ID: 84 J) opens coconuts using two types of underhand tosses: (1) a rolling motion to move it, and (2) a throwing motion up in the air to crack the shell. We discuss this innovative behavior in light of species-specific behavioral propensities.

