A note on enrichment for spontaneous tool use by chimpanzees (Pan troglodytes) (2003)

Morimura, N.

Abstract

Tube feeders from which chimpanzees could access orange juice using either tools or their hands were presented. Results showed that chimpanzees opted to use tools to access the juice in the feeders, even though the use of the mouth and the hands to obtain juice continued to occur intermittently until the end of the task. This finding demonstrated that when chimpanzees have the option to access juice through a variety of methods, they employ all available choices. It also supported the hypothesis that behaviour of captive chimpanzees may come to resemble that of their wild counterparts as a function of behavioural freedom.