Animals using tools are a rare occurrence, and using a tool to crack nuts is considered one of the most complex behaviors in wild animals. Only chimpanzees, capuchins, and macaques have been known to do so. But now, there’s a fourth animal on the list: the orangutans.
Researchers gave a large log and some nuts to orangutans living in zoos and observed that some of them spontaneously used the log as wooden hammers to crack the hard nuts. Of the twelve orangutans tested, four learned to use the log as hammers without ever seeing another animal doing it first.
“Among the great apes, and after chimpanzees, orangutans are the ones known to have the second-largest repertoire of tool use. However, wild animals have not previously been observed cracking nuts,” said Claudio Tennie of Early Prehistory and Quaternary Ecology at the University of Tübingen. “[The] orangutans themselves can develop this complex behavior purely through individual learning,” added study author Elsa Bandini.
Image credit: Claudio Tennie/University of Tübingen