Orangutans can use their own "currency" which they use to buy favours such as winning bananas, scientists have discovered. The apes can help each other get food by trading tokens, learning the value of each token and handing it over only in exchange for favours or food at the right value. Researchers from the University of St Andrews found orangutans could learn the value of tokens and trade them, helping each other win bananas. The discovery is the first evidence of "calculated reciprocity" in non-human primates, according to an article in Biology Letters. The research found two orangutans - Bim and Dok - who live in Leipzig Zoo, Germany, were especially good at helping each other. Initially, they were given several sets of tokens. One type of token could be exchanged by an orangutan for bananas for itself, another type could be used to gain bananas for a partner, and a third had no value.
The apes can help each other get food by trading tokens, learning the value of each token and handing it over only in exchange for favours or food at the right value.
Researchers from the University of St Andrews found orangutans could learn the value of tokens and trade them, helping each other win bananas.
The discovery is the first evidence of "calculated reciprocity" in non-human primates, according to an article in Biology Letters.
The research found two orangutans - Bim and Dok - who live in Leipzig Zoo, Germany, were especially good at helping each other.
Initially, they were given several sets of tokens. One type of token could be exchanged by an orangutan for bananas for itself, another type could be used to gain bananas for a partner, and a third had no value.
