Innovative coconut-opening in a semi free-ranging rhesus monkey ( Macaca mulatta ): a case report on behavioral propensities

The present case report provides a description of the emergence of an innovative, highly beneficial foraging 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.